0.1 Aim of the Introduction

The last decade of the XX century brought with it an important change in the way of dealing with environmental problems caused by human activity. This, in fact, was one step further in the evolution of environmental thought (table 0.1). However, if the 1990's had one specific characteristic, it was the progressive introduction of the concept of prevention, that is, of avoiding environmental problems at their source, instead of dealing with already existing problems. Over this long period of time, it was shown that avoiding negative environmental impact is far more cost-effective than correcting it once it has been created. The advantage of prevention has become clear when it has been necessary to make major investments in correcting the impact of earlier activity for which it had been wrongly assumed that there was no cost if environmental effects were externalised (in any case there was no cost for manufacturers who externalised pollution). Within this process of changing mentalities in favour of prevention at source, a significant role was without doubt played by Cleaner Production (CP). CP is the most widespread method of prevention throughout the world in small and medium-sized enterprises (SMEs), and this is why it is used in this manual.

The aim of this introductory chapter is to give the student an idea of:

• the aim of the document,
• the scope and content of the document,
• the general structure of the document, to be a guide for better use of the document,
• the particular objectives that it is hoped will be attained with the document's publication and the transfer of its content to its readers

0.2 Curricular Introduction

Universities educate specialists who, in the future, whether as educators at different levels or as professionals in industries and institutions, will have a major influence on the behaviour of business and society. Universities are therefore responsible for raising students' awareness, providing them with the knowledge they need and training them to use management tools that, when all is said and done, are what make sustainable development possible. Universities have the ability to develop the conceptual framework for reaching this goal. They should play this role in their own areas of training and research, in public information and in helping to develop the appropriate strategies and policies suitable for these objectives.

As part of this task, universities should:

• Train professionals with the ability to act in a way that is environmentally sound in different areas of science and technology.
• Establish complete education programmes in environmental management and in the tools available for effective management.
• Incorporate a certain amount of environmental education into the syllabus for all disciplines, to ensure that all graduates have enough environmental knowledge to be able to act responsibly.
• Establish specific programmes of technical education in the conservation of resources, the reduction of waste flows, recycling techniques and the evaluation and full resolution of environmental problems.
• Provide these programmes with theoretical and experimental content, encouraging research into all the areas mentioned

0.3 Aim of the Manual

The aim of this document is to provide the student with an updated idea of the principles and methods of CP, and to prepare them for action in the future. It is aimed at university students and professionals who would like to acquire full training in CP, the most widespread method focused on prevention, or to learn about its main concepts in order to incorporate these into a more heterogeneous view of environmental techniques.

This manual is not intended to be purely informative or to be used as an encyclopaedia. Instead it is intended to be educational in the application of the different methodologies and in the elements supporting these methodologies. It is conceived as a guide to introduce CP to future professionals, using experience gained during the development period of CP.

The manual can be used for self-training or with the help of a teacher who makes a monitoring on the progress of the students. This monitoring is of particular interest for the case studies given at the end of the chapters, because often there is not one but several possible ways of interpreting the conclusions or focusing solutions. In specific circumstances it may even be possible to find a more appropriate answer to the self-assessment questions throughout the text than those given in the document. Tutors can apply their own training and experience to judge whether the students' interpretation is reasonable.

0.4 Scope and Content of the Manual

Like many other texts that aim to provide the results of a wide range of different experiences in the form of a methodology, chapters need to be divided depending on their content rather than by the industrial sector in which the experience may be applied. This would be another possibility for training in CP, that is thought to be less appropriate (and more difficult to apply) in a university context.

Fortunately, as a complement to this manual, there is a large quantity of reference material available that can be applied to almost all industrial sectors, which readers will have to use when they want to apply the methodology. A variety of books and manuals provide detailed descriptions for a specific sector. In addition, lots more information can be found on the Internet.

The manual is divided into the following chapters:

• Chapter 1: Prevention at Source and CP

  Chapter 1 explains how CP is integrated into the large-scale objectives of sustainable development. The Rio Conference of 1992 marks a decisive move in this direction and classifies the environment alongside economic and social factors as an indicator of development. In order to rectify earlier patterns of production and consumption, the need for development and the transfer of clean technologies is confirmed.

  The United Nations Environment Programme (UNEP) defines the pattern for CP, a programme of eco-efficiency with environmental and economic advantages, specifically aimed at small and medium-sized enterprises (SMEs). Likewise, the chapter outlines the development process of the concept of CP and its introduction in different regions of the world, including the Mediterranean, showing the role of governments in CP.

• Chapter 2: CP and Enterprise (SME)

  Chapter 2 reviews the relationship between CP and enterprise and provides a definition of the small and medium-sized enterprise (SME). Despite the unanimity reached in CP methodology, there are still great differences in the ways of introducing this methodology to large industrial corporations or to the SMEs and in the factors that play a positive role or provide difficulties for the adoption of CP. Despite the opportunities available, regardless of the type of enterprise, the barriers to the application of CP are very different depending on the enterprise's size and economic possibilities.

• Chapter 3: CP and Environmental Management Systems

  The relationship of CP to other tools focused on environmental improvement is analysed in chapter 3. Some tools are aimed at reflection or to be used as indicators showing to what point development is sustainable or not. Others are tools or strategies aimed at ensuring better use of resources, such as industrial ecology, ecodesign, life cycle analysis, etc., and in particular environmental management systems (EMS). In this regard, ISO 14000 standards have been adopted throughout the world as a specific system of EMS. In Europe, an Eco-Management and Audit Scheme (EMAS) was published in advance. Nowadays the EMAS includes the ISO 14000 aproach as well as the principles of environmental prevention. The European Directive on Integrated Pollution Prevention and Control known as IPPC )also includes the use of best available technologies (BAT) and therefore implicitly includes the use of CP.

• Chapter 4: Economic Aspects of CP

  Chapter 4 outlines the economic aspects required to show the advantages of CP. For the management of a company to be convinced of the benefits of investing in CP, they must have a correct economic perspective of the costs involved in the generation of waste flows and be able to see how the application of eco-efficiency measures helps to reduce these costs, making the company more competitive. This chapter reviews aspects of environmental compatibility, the cost assignation criteria for a specific activity and/or product and the financial analysis criteria that can be used to assess the viability of CP opportunities and to show that CP brings both economic advantages and environmental benefits.

• Chapter 5: CP Methodology

  The methodology for the application of CP is described in chapter 5. The most important characteristic of CP is the need to adopt a simple and coherent methodology which can be applied easily in SMEs. This chapter outlines the components of a CP programme and assessment and reviews the role played by all the people within the company, beginning with top management and including the basic figure of a coordinator who manages and organises, bearing in mind that this is a group effort. The chapter shows the steps required to generate eco-efficient options, which must be technically and economically assessed, and emphasises the usefulness of acting according to priority criteria and of making clear the benefits achieved through CP. The assessment of risks associated with using toxic products is introduced, the reduction of which is included in the definition of the UNEP definition of CP.

• Chapter 6: General Options of Prevention at Source

  Each sector has its own specific CP options, linked to the technology used within the sector, but there is also a series of opportunities that are common to almost all industrial sectors. Chapter 6 lists these CP options at different stages of the productive process, beginning with the more general options, such as Good Housekeeping Practices (GHPs) that must be followed by every industrial plant. The chapter then describes different opportunities ranging from the possibilities of a purchasing department to the application of CP in operations and maintenance, with special reference to the choice of alternative solvents.

• Chapter 7: CP in the Chemical Industry

  Chapter 7 introduces the specific case of the integration of CP into the chemical industry, probably the sector in which most of the alternatives to be found in other sectors can be found in addition to other options specific to this industry. Because of its complexity, economic value and environmental impact, the chemical industry has been subject to a number of studies of ways of improving the eco-efficiency of its processes. This chapter describes how the concepts of eco-efficiency and CP are being introduced into Research and Development laboratories under names like green chemistry. The chapter also discusses the hierarchy of unitary processes and the way to focus research into CP options in chemical reactions, a characteristic stage of the industry, which require scientific knowledge and specialist technology. The case of batch processes, more specific to SMEs, is described in more detail.

• >Chapter 8: >Water Saving in CP Projects

  This chapter reviews the basic concepts of industrial water management. In the past, water was considered an easy access, low cost resource in comparison to other raw materials. Until recently, water saving had not been given sufficient attention by manufacturers in industrialised countries. When it became clear that this resource was not unlimited, that manufacturing processes relied heavily on water, and that the cost of good quality water was increasing, specific measures for the preservation and recovery of this resource were undertaken. Possible means of water preservation and wastewater recycling are described in this chapter. Examples of effective water-saving systems during the rinsing stages in the surface treatment industry, which normally consume large quantities of water, are given. Membrane separation technology is introduced as an example of the modern technologies which are being given most attention by researchers.

• Chapter 9: Energy Saving and CP

  As in the previous chapter, chapter 9 has a specific objective, in this case concerning energy as another specific component of CP. Interest in saving energy was an industrial priority for economic reasons following the energy crisis of 1973, considerably before CP was an organised concept. In fact, the energy experience was useful for the rapid development of a CP methodology. Although specific interest in saving energy declined, it was revived within CP programmes as a result of its important role in climate change. This chapter describes the energy system, and analyses the main tools for energy assessment, together with some of the options for improvement. The beer industry is used to highlight a number of specific applications.

• Chapter 10: Progress and Future of CP

  Chapter 10 outlines ways of measuring the improvements contributed by CP, the role of CP as a form of innovation and the participation of CP in the transition to a sustainable future. Sustainable development depends on the capacity for innovation to reach the X factor multiplication of efficient use of resources. The management of the transition to a sustainable society will require institutional changes in knowledge management and the application of a technological policy that correctly focuses the trajectory into the future. Many industries will be able to make the most of their CP experience to focus their role in this transition.

• Chapter 11: Prevention Practice in Universities (teacher's manual)

  Universities do not usually have the means to send all their students for a training period in CP within an industry, in particular if course attendance is important. This chapter describes opportunities to approach industrial reality with elements that are accessible to all. The Ingenuity Factory is a group exercise along the lines of workplace training exercises, which enables participants to explore within a partially real setting the abilities acquired in their more theoretical education. A more concrete application of CP is the assessment of a family kitchen (the food factory within everyone's reach) observing the analogy of the processes taking place during cooking with real manufacturing processes. Another application is to make an assessment of the laboratories nearby, in the research faculties, to then make a list of CP options. Finally, the diagnosis of a faculty is given as an easy to apply practical case study in any university faculty.

0.5 Document Structure

Each chapter contains a theoretical element with the corresponding table of contents and a practical section including a series of exercises intended to provide a pause for examination and reflection rather than for self-assessment.

In addition, the majority of chapters also contain:

• References to MedClean files for CP/RAC, which provide access to real cases related to the content of the chapter.
• A case study to enable more in-depth reflection and to facilitate discussion on the future progress of the technique studied.
• The majority of the chapters are completed with a proposal for activities to help the student make the transition to action, overcoming the limitations of a document on paper. It goes without saying that as far as possible, the student is recommended to try and gain real experience in a factory in any industrial sector.

1.1 Objective

Cleaner Production (CP) is associated with the industry and the environment. Industry is an economic and social instrument of well-being and quality of life, but at the same time industry has led to environmental conflicts. Therefore, it is included in the goals of sustainable development. In many countries CP has been adopted for pollution prevention at the source.

The goal of this chapter is to:

• Introduce the concept of CP, defined by the United Nations Environment Programme(UNEP) and other institutions.
• Describe the development process of the CP concept and its introduction in countries in the Mediterranean area.
• Emphasize the function of CP as a programme of eco-efficiency, with environmental and economic advantages.
• Describe the role assigned to governments in CP.

1.2 Sustainable Development and CP

The concept of sustainable development [1], [2] became part of everyday language after the publication in 1987 of the report Our Common Future [3], also known as the Brundtland Report, prepared by the United Nations Environment and Development Commission. The goal of the Commission was to link environmental problems to development problems, combining the fight against poverty with the economy and ecology. The first lines of action for sustainable development were defined in 1992 in the the Agenda 21 [4].

While seeking to define sustainable development, the concept of Cleaner Production (CP) was launched by the United Nations Environment Programme (UNEP) in 1989 as the form of production that requires taking into account, conceptually and in their implementation process, all the stages of the life-cycle of a product or process, with the aim of preventing or minimizing human and environmental risk, in the short and the long term.

1.3 Hierarchy of Approaches to Environmental Management

When the dilution of pollutants in the environment proved to be an unsustainable form of environmental management, end-of-pipe treatments were implemented to eliminate or reduce the problems of waste streams, by treating them externally to the manufacturing process they originate from. Within the hierarchy of approaches to environmental management (list 1.1), waste stream treatments are currently considered the next-to-last option. In order of preference, they come just before controlled disposal.

CP allows to prevent or reduce the need for end-of-pipe treatments of waste streams. For example, in the tanning industry, applying a technique of highly spent chromium baths as a CP measure, leads to savings in raw materials while reducing the pollutant load of effluents.

1.4 Definition of CP

UNEP [5] Cleaner Production has defined PNUMA as:

The continuous application of an integrated preventive environmental strategy applied to processes, products and services to increase overall efficiency and reduce risks to humans and the environment. CP is applied to:

• Production processes. Cleaner Production results from one or a combination of the following: conserving raw materials, water and energy; eliminating toxic and dangerous raw materials; and reducing the quantity and toxicity of all emissions and wastes at the source during the production process.
• Products. Cleaner Production aims at reducing the environmental, health and safety impacts of products throughout their entire life cycles, from raw material extraction, through manufacturing and use, to the 'ultimate' disposal of the product.
• Services. Cleaner Production implies incorporating environmental concerns to designing and delivering services.

CP implementation requires a change in attitudes, aimed at guaranteeing responsible environmental management and creating conducive national policy environments and evaluating technology options.

The definition of UNEP has been adopted as such, or with minor differences, in most Mediterranean countries [6]. Only in European Union (EU) countries that associate CP directly with Sustainable Development (Italy) or that equate it with Best Available Techniques (Greece), there is no official definition or unofficial formulation of CP.

1.5 The Origin of CP

1.6 CP and Eco-efficiency

Eco-efficiency is a strategy combining environmental improvement and economic benefits. As such, it allows to achieve production processes that are more efficient while reducing the consumption of resources and pollution (diagram 1.2). Eco-efficiency boosts innovation and competitiveness and can therefore open up significant business opportunities. Its goal is to make economies grow in quality rather than in quantity. In other words, it seeks to increase value with less impact.

Diagram 1.2 CP and Eco-efficiency in Pollution Prevention at the source

The concept of eco-efficiency has been adopted by the World Business Council for Sustainable Development (WBCSD, World Bussiness Council for Sustainable Development) and the Organization for Economic Cooperation and Development (OECD). The WBCSD has gone from using eco-efficiency as a simple concept concepto simple (as it did in 1991) to using it as a vehicle to improve the business performance. The WBCSD has acknowledged a parallel between eco-efficiency and CP; both concepts appeared almost at the both concepts appeared almost at the same time and have developed simultaneously through the exchange of knowledge and experiences, leading to their mutual strengthening [15], [16].

The OCDE also promotes an eco-efficient approach Opportunities are open to all kinds of enterprises although the eco-efficiency implementation formula tends to vary from large corporations to SMEs.

For the OCDE, eco-efficiency means the efficiency with which resources are used to meet human needs. It can be considered as the relation between the production or services obtained (output) and the sum of environmental pressures generated (input). This relation can refer to either a company, an industrial sector or to the economy as a whole. The OECD studies confirm the CP experience whereby manufacturers have found cost-effective ways of reducing the use of materials, energy and water by 10-40 % per production unit. Likewise, proven technologies can reduce the use of toxic substances by at least 90 %.

1.7 The Role of Governments regarding Prevention

The OECD attributes to governments the responsibility for establishing a political framework, aimed at reducing the gap between social and private targets and reinforcing the efforts to be applied by companies in order to improve their economic, environmental and working conditions. As instruments to be used, the OECD supports regulations and economic incentives as well as the creation of a climate that encourages innovation and allows to boost new options improving those conditions. The governments must also play an important role in communication, raising community awareness regarding the difference between waste prevention and more traditional activities, such as recycling [17].

For the OECD, CP and eco-efficiency are the instrumental stimuli that have allowed to increase waste prevention efficiency. This organization calls for a governmental strategy that will prioritize waste or materials presenting an intrinsic risk or a significant indirect impact during their extraction, use and management.

1.8 Case Study: CP in Mediterranean Countries

Since the mid-nineties, Mediterranean countries have shown a continuous progress in the adoption of measures that have either directly or indirectly encouraged CP[6], [12]. centres have been created, or are in the process of starting up in most East and South Mediterranean countries.

This progress has not only been boosted by the national CP centres but other institutions have also participated including, chambers of commerce and industry, universities and other centres as well as some specialising in energy.

On the other hand, in North Mediterranean countries there are very few centres specifically devoted to CP, except in Spain, where CP is considered as part of the general programmes adopted by the agents responsible for waste management.

1.9 Activities

2.1 Objective

Cleaner Production is equally convenient and applicable to any size of enterprise, although the means available for its implementation are not the same. The goal of this chapter is to review the relationships between CP and the enterprise, with special focus on small and medium enterprises (SME):

• How SMEs are defined and their role in modern production processes.
• Differences in the introduction of eco-efficiency in large industrial corporations and in SMEs.
• Focusing on CP programmes in SMEs and increased competitiveness arising from its implementation.
• Factors that have a positive or negative influence on CP implementation.

2.2 Industrial Production Structure

Industrial production takes place in enterprises of very different characteristics, based on:

• the technological sector to which they belong,
• their size,
• or their organisation structure.

Even in the most industrialized countries, there are enterprises with very simple structures and functions. At the other end of the scale, there are large corporations with multiple production centres and many companies that, independently from their size, apply modern production processes that are also quite complex.

Eco-efficiency can be implemented in all kinds of firms. In fact, many firms included in the definition of small and medium enterprises SME often have the capacity to implement innovative improvements that large companies, with excessively centralized structures, do not have.

2.3 What is a Small & Medium Enterprise (SME)?

SMEs generally have features which distinguish them from large enterprises, such as [19]:

• Lack of a dominant market position.
• Management structures that are less defined, often family businesses that are managed by the owners.
• They act without the support of participated companies, which is often linked with more difficult access to financing and external aid.

SMEs do not respond to a specific definition but depend to some extent on the territory in which they operate which changes over time, particularly with regard to financial factors. A distinction should also be made between small and medium enterprises and micro-enterprises.

2.4 SMEs in the Mediterranean

The relative contribution of SMEs to the environmental impact in the Mediterranean cannot be specified, although it is probably significant as at least 80-90 % of all enterprises are SMEs, their contribution to the total production is important and they prevail in traditionally polluting sectors such as the textile, tanning, printing, and surface coating industries, etc.

In some countries, the availability of industrial land, the demand for cheap consumer products and the abundance of unskilled labour have led to the development of SMEs with a low level of technology within the cities. Many of these enterprises have been favoured by government protection and tolerance, which has allowed them to continue managing their businesses in an inefficient and not very productive manner. In these cases, the development model has led to the appearance of pollution black spots.

Some North-Eastern Mediterranean countries are undergoing economic restructuring programmes as a result of the political reform following the collapse of Communism and the beginning of a gradual market liberalisation process. The end of central planning has led to legal and institutional reform and a privatising process. Although they are not all developing at the same speed, these countries are showing a high level of social commitment and implementing technological improvements that coexist with obsolete and polluting technologies. In this situation, the SMEs have started their own process of development and contribution to industrial production.

2.5 Environmental Performance and Competitiveness

In order to link their processes with the environmental requirements, large companies usually have their own team of experts in environmental management, or sufficient resources to engage the external services that adapt to their extra requirements. On the other hand, SMEs often have a biased perception of what CP is and difficulties in implementing it and converting part of the standards required into a favourable factor.

Nevertheless many SMEs have a capacity for innovation and flexibility to adapt to present conditions that is higher than for large enterprises. These SMEs can benefit from the fact that the industrial complexity requires decentralized and flexible production systems able to adapt more readily to the waves of changes that the market imposes CP has the necessary ingredients to be the stepping stone for them to advance towards an innovative strategy. On the other hand, enterprises that have a narrow perception of environmental issues, can take the opportunity to become more competitive by implementing eco-efficient measures, thus securing themselves a place in the industrial future.

2.6 Incentives for CP Implementation

The first reason enterprises are given for implementing environmental management including CP is to comply with legal requirements. However, whereas other environmental measures are costly, CP measures are self justifying as they represent a tangible economic benefit or a less evident business performance improvement.

Therefore, some of the many incentives which can be identified to implement CP, are:

• easier compliance with the regulation in force,
• improve the business image,
• advantages for obtaining permits and simplified proceedings,
• raw material and energy saving,
• savings in waste stream management: treatments and/or disposal,
• economic benefits,
• advantages with insurance companies,
• reduction of possible civil and criminal liability,
• improved working conditions concerning safety and hygiene,
• a safer value for shareholders, etc.

2.7 The Customer-Supplier Chain

There is another reason for certain enterprises to implement a CP programme. Some large enterprises often require SMEs suppliers to have a sustainable policy and performance. Contrarily, an SME may be excluded from the supplier catalogue. More and more, SMEs will will find themselves having to implement an Environmental Management System (EMS) that meets with the customer's approval, as integral part of a production chain.(SGA) que satisfaga al cliente, como parte integrante de una cadena de producción.

Adapting to certain requirements from industrial customers and consumers and being able to show an appropriate ecolabel could be as important at present as quality requirements or just-in-time (JIT) supplies. In the same way that the supplier can be requested to have a quality standard, such as ISO 9000, he can also be requested for an environmental quality guarantee, such as an Environmental Management System (EMS) (chapter 3) which includes some form of CP.

2.8 Difficulties in CP Implementation

In return for the mentioned incentives, CP shall have to overcome a series of difficulties for its implementation. In order to bridge the obstacles, these difficulties shall need to be identified and overcome, at the same time as the benefits of CP are explained. There are still serious obstacles in many Mediterranean countries for the implementation of CP [20].

Among of the main difficulties found in some countries, are the following:

• At regulation and government level:
  • Absence of an efficient regulatory framework, lack of the legislative and administrative mechanisms required to stimulate CP and lack of governmental commitment or institutional support.
  • There is often an overlapping of the actions of various governmental organisms with different driving forces (industry and environment) and/or a clear lack of boundaries between the competences of state or local bodies.
  • Insufficient enforcement of existing regulations, sometimes with unequal demands from one region to another in the same country.
  • Lack of institutional financial aid for the promotion of preliminary studies or projects to evidence the advantages of CP.
• At company level
  • Little willingness of businessmen who are reluctant to change and mistrust innovation at top management level or changes in management and production at intermediate level.
  • Conservative attitude of SMEs due to lack of an appropriate structure, without experience in the implementation of measures such as CP.
  • Incapacity of many companies and lack of expert support to apply cost analysis accounting systems which will allow them to identify the environmental costs and economic benefits of CP.
  • In several countries, lack of participation from industrialists in setting up development schemes, particularly when the country's priorities are mapped out according to the government's political agenda.
  • Ignorance of the advantages of CP and lack of information (existing) regarding positive experiences in the relevant industry.
  • Lack of specialized human resources for the technician formation and worker training.
• At economic and financial level
  • Lack of financial resources for implementing measures that previous assessments have shown to be beneficial for the environment and competitiveness of the enterprise.
  • Difficulties in obtaining external financial aid in precarious business situations (which occurs quite frequently) even though the CP options are cost-effective by themselves.

On a macroeconomic scale, the international political scenario does not acknowledge the complex relationship between economy and environment, required for sustainable development. The national accounting system, from which the main economic indicators derive, that are used to develop policies and measure their effectiveness, does not take into consideration the depletion of the natural resources or the pollution of the land. Therefore, they do not consider sustainable development nor do they encourage the internationalisation process of environmental costs

Moreover, some Mediterranean countries continue to subsidise the industry's energy and water costs, leading to a lack of motivation for adopting techniques that make a rational use of the resources.

2.9 Characteristics of Enterprises

The implementation of a CP programme is made easier when there is a good perception of the particular characteristics of the company in which it will be implemented. During the initial stage and particularly if the CP simplementation is carried out with an external consultant, aside from the specific details of the company such as address, persons in charge, industrial sector, size, etc., it is convenient to obtain a characterisation of the industry with regard to the following aspects:

• Technical Complexity of Manufacture

  One of the most specific factors of an enterprise is its technical manufacturing complexity. Up to 10 groups have been proposed for classifying enterprises [21], although to focus the CP it is sufficient to reduce these to four principal groups:

  • Productions per units or in small butches
  • Mass production or in large butches
  • Chemical based batch processes
  • Continuous flow processes.o

  When different products are manufactured, knowing the percentages of the different products and the production sequences helps in the planning of the assessments. The environmental problems will most likely be concentrated in very few products or production stages, which will require further attention.

• Analysis of the Organisation's Structure

  To obtain a formal analysis of an organisation's structure, some questions can be asked about some of the sizes or primary variables of any organisation [21]:

  • Specialisation: To what extent are the activities of the organisation divided into specialized tasks?
  • Standardisation: To what degree have the processes and regulations been applied?
  • Formalisation: To what extent are instructions, processes, etc. in writing?
  • Centralisation: To what extent has the decision-making authority been delegated?
  • Configuration: Is the organisation a very vertical or not too vertical structure? What percentage of personnel is specialized? What percentage of technology comes from external aid?
• Integration in Customer/Supplier Chains

  It is very important in modern production processes, to assess an enterprise's level of integration and dependence in the customer-supplier chain. It is convenient to know some aspects on the degree of interdependence between both parts:

  • Level of integration with the supplier: simple orders vs. long term contracts
  • Level of integration with the customer: simple orders vs. long term contracts
  • Dependence of the enterprise on its most important customer
  • Dependence of the enterprise on its most important supplier
  • Sensitivity of the enterprise to the production volume of its customers

2.10 Functional View and Process

There are two main views for an organisation; the functional view and the process view. The classic division of work has led enterprises to set up departments for their organisation. Each functional department contributes to the creation of a product or service through tasks that can be managed separately. However, many activities cross over the borders of the departments with the so-called work flows or processes between departments. Total cost management systems are behind this view of the processes because, amongst other advantages, they allow to assign general costs on the basis of the cause-effect relationship (chapter 4).

The process view focuses on the work itself, identifying the work elements (processes) that must be developed for the company to function. This way of seeing the company is advantageous in the customer-supplier relationship because it corresponds to the way in which the customer interacts with the enterprise: hiring, quality assurance, reception of products and services, payments and after-sales service requirements. The basic processes are divided into sub-processes, which in turn are divided into activities. A clear understanding of which (work) processes occur in an enterprise will allow the businessman to apply continuous improvement measures and achieve a total and effective management based on costs in activities (chapter 4).

Following are some examples of typical operation sub-processes:

• product planning
• pricing of materials
• procurement
• planning of equipment and facilities
• conversion planning
• quality control
• maintenance

Example of activities analysis applied to a purchase process of material:

The process view focuses on the work itself, identifying the work elements (processes) that must be developed for the company to function. This way of seeing the company is advantageous in the customer-supplier relationship because it corresponds to the way in which the customer interacts with the enterprise: hiring, quality assurance, reception of products and services, payments and after-sales service requirements. The basic processes are divided into sub-processes which in turn are divided into activities. A clear understanding of which (work) processes occur in an enterprise will allow the businessman to apply continuous improvement measures and achieve a total and effective management based on costs in activities (chapter 4).

Following are the six basic processes [22]:

• Executive
• Internal support
• Obtaining new business
• Design of new products and services
• Operations
• Customer service.

2.11 Environmental Activity Indicators

In order to see the evolution of some of the key aspects of the environmental performance of an enterprise and easily communicate this behaviour, it is advisable to use environmental indicators [23], [24]. These indicators offer information on the current situation and allow to carry out a comparative follow up of improvements achieved over time. For many enterprises, it may be very important to formally adopt the concept of environmental performance assessment developed as a ISO 14031 Standard [25].

For the OECD, an indicator is a parameter or a value derived from parameters, that points to/provides information on/describes the state of an issue/environment/area in terms that go beyond those directly associated with the value of the parameter [26]. A parameter is a measured or observed property, just as an index is a series of aggregated or weighted parameters or indicators. The analytic framework that is generally adopted for environmental indicators is the pressure-state-response (figure 2.1).

Figure 2.1 Framework for Environmental Indicators: Pressure-State-Response

From a business management viewpoint, the indicators fulfil three basic functions:

• They warn against management aspects that divert from the correct state.
• They offer information on the overall performance and allow to plan improvements.
• They facilitate internal and external communication on the compliance of the operation.

The effectiveness of the indicators depends on the extent with which they manage to:

• Cover significant aspects relating to:
  • environmental legislation
  • the enterprise's environmental policy
• Be objective and based on available and verifiable data.
• Be simple to use.
• Respond to the concern of the parties involved.
• Allow comparisons.
• Be simple to implement and obtain at a reasonable cost.

Generally, a group of indicators is adopted--not too many--covering the different environmental aspects.

Lowell University has focused on six main aspects of sustainable production [24] to be taken into consideration when a series of environmental indicators is proposed (see case study in section 2.12):

1. Consumption of resources: reduce consumption of materials, water, energy; use renewable energies, etc.
2. Waste flows: reduce impacts on the natural environment; toxicity, greenhouse effect, etc.
3. Economy of the system: environmental costs; faulty refunds, etc.
4. Workers: accident tax, training, etc.
5. Products: recyclability, packaging biodegradability, etc.
6. Social and community development: relations with the neighbouring community, local workers, etc.

2.12 Case Study: Pollution Prevention in Process Industries

For Haas, there is a huge difference between an operational view (how can we improve?) and a strategic view (how can we use that improvement to outdo our competitors?) [28]. Eight aspects of production that are interrelated need to be taken into account. Decisions are essential in these eight aspects of manufacture to achieve strategic improvements. Berglund [29] has reintroduced the eight aspects that Haas identified as the basic aspects and has studied what role pollution prevention plays in all of them:

1. Product Design

   Products must be designed that are less toxic, less persistent, easier to recycle or to treat. The focus should be on:

   • preventing certain products from entering the environment (eliminating CFCs for example);
   • making them easier to eliminate from the environment (use of recyclable plastic, for example)
   • making them easier to reuse (vehicles that are easy to dismount, for example).
2. Process Design

   From their experience in Union Carbide, the authors have concluded that prevention in industrial plants advances in stages:

   • Phase I: the first efforts focus on alternatives that are simpler, more obvious and cost-effective; these include Good Operating Practices, waste segregation, simple recycling without treatments. They are applied to the operation rather than to the physical system and have a good economic return.

   • Phase II: operations emerge that are more complex and expensive and often related to equipment modification, process modifications and process controls. This phase can include adding or adapting ancillary equipment for simple treatments at the source, possibly to recirculate materials. These generally offer less immediate return on the investment and require further justification.

   • Phase III: focuses on intrinsic waste (inherent to the basic process configuration), more complex recycling, more essential changes in the process, changes in raw materials and catalysts, or product reformulations. As the payback periods are longer, they are easier to introduce when a new unit or process is developed.

3. Configuration of the Plant

   Two aspects are particularly important. The first is the complete integration of the plant; that is to say, a plant that can make the best use of all the products and by-products whithin the same plant. It is easier to achieve by extending the concept to a customer-supplier chain. The second aspect is easiness with which maintenance is carried out and to introduce changes in the process.

4. Information and Control

   In addition to a system which allows optimisation of yields and minimisation of unwanted by-products, a control must be made available of the waste (or of the waste management companies when the responsibility does not end with the delivery of waste to the management firm), to minimise out-of-control situations (with a solid system).

5. Human Resources

   In order to involve all the workers, their formation and training in the identification of prevention opportunities is important, as well as appropriate involvement and the acknowledgement and rewarding of improvements.

6. Research and Development

   Four aspects are considered important:

   1. Finding new processes and modifying existing processes
   2. New segregation technologies
   3. Analytical techniques to help identify pollution sources
   4. Support for incremental improvements.
7. Customer - Supplier Relations

   Waste prevention and reduction are easier to achieve with a close customer-supplier relationship. This includes suppliers of equipments and raw materials.

8. Organisation

   Support and commitment must come from all levels of the enterprise, which will be organized to encourage team work and interaction between all the personnel. For example, it is to be noted that the accounting department plays a major role in the identification of the best opportunities to acknowledge the benefits of a prevention programme, which is not always borne in mind.

Berglund proposes a group of characteristics from each functional area, implementation aspects and trends related to prevention (and CP) (table 2.1).

2.13 Activities

3.1 Objective

In the framework for a sustainable development, several approaches have been promoted to seek improvement, that are related to eco-efficiency and CP. Some of them are more intended for reflection or being used as indicators of how (un)sustainable a development is (material flows, factor 4, ecological footprint, etc.). Others are tools or strategies aimed at improving the use of the resources, from the planning of systems and products to the decision-making, either by the manufacturer or from the consumer's viewpoint (industrial ecology, ecodesign, life cycle assessment, etc.). The latter can find a place within the general framework of an Environmental Management System (EMS) that every enterprise should have [30] and [31].

The objective of this chapter is to:

• introduce environmental management systems (EMS) and its ISO 14000 standardized form.
• explain the additional step in communication transparency sought by the EMAS in the European Union (EU), aimed at guaranteeing the environmental performance of enterprises.
• outline the contribution of CP to EMSs and the relation with the best available technologies (BAT).
• check some of the other environmental tools that are associated to CP and are part of the EMS.

3.2 Environmental Management Systems (EMS)

3.2.5 Dynamics of EMS

The environmental management system EMS starts with the declaration of an environmental policy of the enterprise that includes at least the commitment to comply with the existing legislation and a continual improvement of its environmental management. The EMS implies a progressive and continual action in four stages: plan, do, check and act. It is often compared to the Deming wheel, which uses cyclic activity to progressively improve its environmental performance over time. The goals set in the EMS must be as quantitative as possible.

3.3 Environmental Audit

The environmental audit is a key factor in EMS. It includes a systematic, documented, periodical and objective assessment to check that the organization, the management and the environmental equipment is in good operating condition and, in the case of the EMAS, for example, it ensures:

• Compliance with the plans stipulated for environmental management.
• Appropriate implementation and maintenance.
• Delivery of information on the results of the audit is supplied.

Following are the main elements of the environmental audit (ICC) son:

1. Total support from the management, that is shown openly in all the stages of the audit.
2. Objectivity of the audit team, that implies being sufficiently independent from the subjects audited.
3. Professional competence of the audit team, sufficiently qualified and experienced.
4. Well defined and systematic procedures to guarantee a total and efficient audit of important subjects.
5. Well documented process and clearly written reports.
6. Assurance of the quality of the audit through appropriate mechanisms to lend consistency and reliability.
7. Follow up of the facts identified through the implementation of appropriate measures.

3.4 Other Environmental Tools

3.4.1 Industrial Metabolism and Ecology

The concept of industrial metabolism was developed [37] on the bases of the analogy between biological organisms and industrial activities, and defined as an integrated and complete series of physical processes that convert raw materials and energy, plus work, in finished products and waste streams in a more or less stable condition. The economic system acts as a metabolism regulating mechanism through the price mechanism. The limited scope of the metabolic function can be developed, among other functions, until attaining the notion of industrial ecology.

The concept of industrial ecology is based on the analogy that can be made between the natural ecologic systems and the industrial systems. In the food chain of biologic systems, some organisms become the food source of other organisms and generally, the waste produced by an organism can be used as a source of material and energy for another organism. A mature ecological community behaves like a waste stream minimization system. Industrial systems and processes are also interactive. The waste streams of some processes can be used to feed other processes. The study of the material flows of an industrial system may reveal opportunities for recycling or the reuse of materials.

Industrial ecology seeks a global balance amongst all activities, beginning with the life cycles of products and production systems. A concept which is central in industrial ecology is the evolution of the industrial system from an unsustainable linear system to a cyclical system to achieve this balance [38]. CP would be included in industrial ecology as a further element of promotion of sustainable production and consumption.

Figure 3.2 Kalundborg Industrial Ecopark (Denmark)

Examples of this are the industrial ecosystems of the Kalundborg ecopark in Denmark [39] and the NASA Closed Life- Support System, suggested for space colonies.

Figure 3.3 NASA Closed Life-support System

Figure 3.4 Transition from an Unsustainable Linear System to a Cyclical System

A specific example of applying the concept of industrial ecology can be found in the reintroduction into the food chain of whey from dairy product manufacture, as described in MedClean file no. 40 (Egypt).

From a viewpoint of industrial ecology, it has been criticized that CP has two limitations [40]. The first is that it is aimed at existing production systems and the second is that it concentrates its action on opportunities that improve competitiveness while reducing environmental impact (although this is where the maximum interest of CP lays and the main reason why CP is accepted by industrialists). Industrial ecology would like to overcome these limitations by addressing its action to any sphere of the production system, including the initial design of products, processes and services, as well as all the environmental impacts, even those that do not report any economic profit.

3.4.2 Ecodesign

Existing production systems were the main focus of CP during the first decade of its implementation, despite the fact that in this period UNEP had made it clear that products were also included in its definition. Meanwhile, ecodesign was developed separately, focusing particularly on packaging and consumer products.

Ecodesign (and its US equivalent DfE, Design for Environment) integrates the prevention of environmental impacts linked to the product in the design stage. As it incorporates a strategy of maximum added value of the products, it is part of a wide eco-efficiency concept and can be translated as the aspect of CP applied to products [41] with the corresponding barriers and stimuli for its introduction [42].

An appropriate example of ecodesign is MedClean file no. 8, concerning the reduction of packaging cardboard consumption through ecodesign (Malta).

Ecodesign includes improvements in:

• product concept and function
• choosing materials with a lower impact
• planning to reduce the impact of the production process
• planning to minimize the impact of distribution: packaging and transport
• optimize product use
• minimizing management at the end of product life.

The design of industrial plants has not received the same consideration from the Public institutions, rather it is the engineering firms themselves and the manufacturers who have boosted the introduction of environmental improvement and the implementation of safety measures aimed at reducing all kinds of risks [43].

Various techniques have been developed in the specific methodology of ecodesign. The MET matrix (figure 3.5) and the Ecodesign Strategy Wheel (figure 3.6) are two examples of the tools used for the analysis of existing products and the assessment of improvements [44].

The MET matrix is a qualitative tool to carry out a functional analysis of the environmental profile of a product. In each stage of a product life cycle (from the production of raw materials to the end disposal) environmental impacts are introduced divided into three groups: material cycle, use of energy, toxic emissions.

The Strategy Wheel enables the main areas in which product improvement is intended to be viewed, evaluating the profile from 0 to 5.

Figure 3.5 Example of MET Matrix Applied to a Coffee Machine

		Cycle of materials Inputs/Outputs	Energy Use Inputs/Outputs	Toxic emissions Outputs
Production and External supply of materials and components		-copper (exhaustible material) -zinc (exhaustible material)	-high energy content of materials	-fire delayers on printed circuits -flow improvers for injection moulding -benzene emissions -isocynanide emissions in paint and gluing
Internal production		- metallic waste - plastic waste	- process energy
Distribution			- energy for transport
Use	operation*	- plastic glasses (1,472 kg polystyrene) - filter paper (90 kg) - used coffee (2,944 kg.) - plastic spoons (110 kg. polypropylene) - cleaning material - dirty water (4,160 l) - water filters (20)	- inefficient energy use in the boiler
	service	- parts that brake easily	- transport of maintenance service
End of life of system	recovery	- valuable parts are not reused: - the boiler - machine disposal (37 kg) - packaging - non-recyclable plastic (5 kg) - printed boards (0.5 kg)
	disposal			- printed circuits (0.5 kg) - copper - zinc
(*) values calculated for the consumption of 4 cups of coffee per day for 40 persons, for 10 years (**) Elements requiring attention

Figure 3.6 Strategic Circle of Ecodesign

3.5 Case Study: an Introduction to Design Based on SME Life Cycle

Even in a country as environmentally advanced as Canada, it is difficult to gather evidence that SMEs are complying sufficiently with a coherent environmental strategy. Although the spreading of the ISO 14001 standard could be taken as an indicator of environmental awareness, in some countries, it is rather a reflection of the position of multinational enterprises and their subsidiaries. This is one of the conclusions of a study based on a sample of 386 SMEs with some environmental awareness, distributed in four sectors of activity: printing, wood, metal and electrical/electronics [47]. The authors concluded that to introduce the design based on SME, life cycle, a five-stage learning curve is followed (figure 3.7).

Figure 3.7 The 5-stage Learning Curve

The assessment of the progress made can be carried out based on four mixed indicators of the level achieved:

1. Green Design
   • Raw material
     • choose materials that can be recycled or that are less environmentally harmful
     • reduce the amount of raw materials
   • Energy
     • reduce the energy required to use/operate the product
   • Product life time
     • extend product life time
   • Ecodesign
     • design the product to accommodate it to many future users
     • design the product to make it easier to repair
     • design the product to make it easier to dismantle
     • design the product to make it easy to recycle
     • design the product to make it easy to manufacture
2. Green Production
   • Requirements for suppliers
     • choose subcontractors based on their environmental performance
   • Energy
     • reduce energy required for product manufacture and assembly and
   • Emissions
     • reduce polluting emissions
     • treat or capture polluting emissions
   • Waste
     • minimize waste
     • guarantee proper waste discharge/disposal
3. Recycling
   • Procedures
     • establish recycling procedures
     • establish appropriate procedures for hazardous substances at the end of product life cycle
   • Infrastructure
     • guarantee the existence of recycling infrastructures
   • Packaging
     • produce recyclable packaging
4. Environmental Management
   • Policies and procedures
     • detailed environmental policy, in writing
     • proactive environmental policy that exceed the legal requirements
     • establish environmental goals that can be quantified
   • Monitoring
     • monitoring of environmental costs and profits
     • regular environmental auditing
     • regular reassessment of the EMS
   • Personnel
     • assigning of roles and responsibilities in environmental programmes
     • adequate training of personnel
     • wages and promotion of personnel based on environmental goals

Following are some conclusions from the authors of the study:

• At the beginning of the millennium, the level of implementation of ISO 14001 is low and has practically not reached stages IV and V.
• The environmental initiatives of SMEs are largely affected by the fact that they are suppliers of large corporations or, in some cases, by a wish to imitate their competitors tactics.
• Although responsibility, image and financial benefits are the main motivations for implementation, business managers find an added value in the innovative aspects, management, production and process, associated with promotion in the environmental awareness scale.

Of the four sectors studied:

• The printing industry shows the best results, probably due to its experience in CP (substituting solvents or using prewashes for examples) and recycling (intensive in paper or use of recycled soya-based dyes).
• The best results in the electrical/electronic and mechanical industries, are in green design and recycling. Ecodesign, the use of benign materials and low energy consumption of products are the main aspects.
• The wood sector has taken initiatives, particularly in CP and to make their products greener (as when using timber preservers).

3.6 Activities

4.1 Objective

For a company's management to be objectively convinced of the interest in investing in CP, it must have a proper financial view of the cost involved in the generation of waste streams, and it must also be able to verify how the implementation of eco-efficiency measures will help the enterprise reduce these costs and make it more competitive. CP strives to obtain a financial and environmental benefit, simultaneously. However, many managers, due to lack of accounting evidence, think that the benefit of one of these factors will always act against the benefit of the other.

This chapter reviews:

• Some environmental accounting aspects required to better understand the environmental costs involved in a company and that are often included in the overall costs.
• criteria for assigning to a specific activity and/or product, the part corresponding to costs that are common to various activities.
• criteria of financial analysis that can be used to determine the feasibility of CP options and to evidence that CP provides both financial advantages and environmental benefits.

4.2 Environmental Management Accounting

4.3 Support Accounting Techniques

There are various types of advanced accounting systems developed for management assessment, that are applicable to environmental management and can be used to support CP programmes [51], [52]. Following are some of the main forms applied:

• Total Cost Assessment

  Total cost assessment is a comprehensive long-term analysis of all the costs and savings that an organization obtains, or could obtain directly, when making or contemplating an investment. It also represents the integration process of the environmental costs in the analysis of the general budgets.

• Activity-Based Costing

  The activity-based cost system is a process in which all the costs of an organization are allocated, directly or indirectly, to the products or processes that generate them. Traditionally, many of these costs are assigned to overhead accounts.

• Life Cycle Costing

  In the method of costs during the life cycle, all the costs are identified with a product, process or activity throughout their life cycle, from the time the raw materials are acquired to their disposal, regardless of whether they are originated by the organization making the investment, other organizations or society as a whole.

4.4 Cost Allocation

Transferring environmental costs from the item of overhead (or indirect) costs to direct costs requires an allocation process of the environmental costs to the products or processes that generate them. The allocation process is important because, if it is not carried out properly, a process or product can bear costs that do not correspond to it and this will affect the real production cost or hide the financial incentive represented by a certain measure of CP. The more accurate the knowledge of the source of the costs, the easier it will be to show the management the implicit eco-efficiency of CP options and the interest in applying some measures.

The basis of cost allocation must be the identification of a cause-effect relation between the cost and the goal pursued with a specific activity. Cost allocation decisions must reflect precisely and quantitatively the basic ideas and criteria adopted jointly by the different departments of a company. It may be necessary for the allocation process to proceed in stages, for example due to crossed dependences between auxiliary services and waste stream treatments.

4.5 Financial Analysis of CP Options

When CP options imply investments, the part of financial profit implicit in eco-efficiency must be justified as for any other production project. In order to show the advantage of implementing a CP, option, it is necessary to apply the same financial analysis tools as those applied to the company's other projects, with which it will have to compete to secure a share of the monetary resources; and although these are always scarce, they are affordable if they boost the company's competitiveness. The criteria of profitability generally applied are [53]:

• Investment Payback Period (IPP)

  The IPP is defined as the period that the accumulated differential cash flow requires to compensate the investment made for the project. The differential cash flow is the net saving imputable to the implementation of the option proposed when compared to the current production process. With the IPP, the manager can know exactly when the changes introduced in his company will start to yield net profits in his operating account. Occasionally criticized by economists as it does not take into consideration the price of money, it is however useful because of its simplicity. It is calculated as:

  

  It is generally considered attractive enough if the IPP is less than 3 years. Otherwise, the analysis can be studied in depth with other financial analysis tools.

• Current Net Value of Investment ( CNV)

  The CNV is the updated value of the differential profit generated yearly. It represents the profits that will be generated during the lifetime of the investment measured at the beginning of same. The higher (positive) the CNV, the more interesting the investment. It is calculated for n years of the investment's lifetime, such as:

  

  where:

  • i is the specific year of the project (year i=0 being the year of application of the investment, which begins to yield income in the year i=1).
  • r is the interest rate (cost of money for the company or yield of an excess of financial resources).
• Internal Rate of Return (IRR)

  The IRR is the interest at which the current value of the differential profits accumulated each year equals the value of the investment carried out. The higher (positive) the IRR, the more interesting the investment. It is calculated by equalling the CNV to zero:

  

At the time the decision is made, the business manager must also bear in mind the intangible benefits, that are difficult to quantify but that are unquestionably generated by introducing CP measures.

MedClean file no. 1 contains a good example of minimisation opportunities economic evaluation which completed the pollution prevention diagnosis in a car battery manufacturer's in Tunisia.

4.6 Case Study: Cost Allocation in ISO 14041

Generally, the technologists do not participate very much in the development of cost allocation methods [54]. However, recently the involvement of technicians has increased following the ongoing introduction of EMS and the implementation of allocation methods for materials and pollutants in the life cycle evaluation in ISO 14041 [55]. The goal of LCA The goal of LCA is implicitly to anticipate the environmental consequences of our actions. However, different forms of assignation of material consumption and waste streams in multifunctional processes result in different types of information, leading to a series of conclusions in the assignation processes that are transferrable to the allocation of costs.

The conclusions reached are not always easy to sum up. Assignation based on causal, physical interactions (based on the production volume of each product, for example) between functions is possible if the functions are physically independent from one another. However, the assignation problem can seldom be solved with a simple division and will require using an expanded system. The problem of assignation is even more complicated to solve when instead of assigning materials, costs must be allocated: which cost is allocated to the product and which to the byproduct, since the market will only accept the byproduct if the price is low enough? The assignation must bear in mind the effect, however little, on the production volume of the function exported as a byproduct.

The expanded system, or an appropriate approach, may help to resolve the assignation problem. The latter can be solved if there is a production (generation) alternative of the function exported, that indicates what are the limits of the assignation. If for example, byproduct B can be manufactured in some other way, an excessive assignation would prevent it being introduced as a useful product and convert it into waste, loading onto product A in a much worse way. The alternative gives the extra information required to decide on the assignation limits.

The system shows a multifunctional process and the activities that can be affected indirectly by a change in the production of B. As the assignation cannot be decided considering the process, the expanded system is used with an alternative production that will allow to decide what allocation can be made to product B.

4.7 Practical Exercises

Exercise 3

Cost Allocation

In a electrolytic silver-plating process a cost assessment has been carried out based on activities (recorded in the financial accounting of the company as indirect costs) according to the distribution indicated in the following table [adapted from reference 9]. Specific costs were allocated to liquid streams (L), sludge (S), vapors (V), particles (P), worn polishing materials (G) and filtrates (T).

Determine the contribution percentage of indirect costs per stage and polluted phase. Use a Pareto Diagram (chapter 6) for a graphic representation of the most important streams.

(Note: the cost distribution is relative. It is referred to a calculation basis of 10,000 units that enables to calculate the cost distribution percentages with two decimals: 100.00 %).

Diagram of the Electro-Silver Plating Process

Indirect Cost Allocation (based on 10,000 units)

Stages		Raw material	Management	Treatment	Disposal	Audit	Labelling	Laboratory	Protection equip.	Training
											2. Stripping	L	50	105	325	150	15	25	40	10	15
S	20	410	500	850	80	50	350	100	200
V	0	50	0	0	10	0	0	10	15
3. Acid washing	L	20	40	100	60	15	5	15	5	5
	S	5	95	60	140	15	15	50	25	40
	V	0	50	0	0	10	0	0	10	15
4,8,10,11. Rinsing	L	50	55	20	20	5	0	10	0	0
											5,12. Worn polishing materials	P	5	0	0	25	0	0	15	10	0
G	10	25	0	50	0	0	0	0	0
6. Soda cleaning	L	20	75	85	65	0	20	0	30	25
	S	10	180	275	350	40	25	150	45	100
	V	0	75	0	0	10	0	0	15	20
7. Neutralización	L	5	20	45	25	5	5	5	5	5
	S	5	55	60	100	10	5	40	10	25
	V	0	50	0	0	10	0	0	10	15
9. Silver plating	L	950	90	125	100	0	25	0	35	25
	S	300	265	325	525	50	30	230	55	150
	T	0	0	0	80	0	10	0	0	25
Total		1450	1640	1920	2540	275	215	905	375	680

The solution of the exercise is available.

Stages		Sum
2. Preparation	L	735
	F	2560
	V	85
3. Acid washing	L	265
	F	445
	V	85
4,8,10,11. Rinsing	L	160
5,12. Polishing	P	55
	G	85
6. Soda cleaning	L	320
	S	1115
	V	20
7. Neutralization	L	120
	S	310
	V	85
9. Silver plating	L	1350
	S	1930
	T	115
Total		10000

Pareto Chart

The first four cost factors represent more than 70% of the indirect costs registered. The influence of stages 2 and 9 is important enough to require prioritizing attention when looking for improvements.

5.1 Objective

The most important characteristic of CP is having adopted a simple and coherent methodology that is easily applied in SMEs, CP is the successor of the energy audit methodology promoted at the end of the seventies, improved through years of implementation until becoming extremely efficient. This chapter:

• Describes the components of a CP programme and of a CP assessment.
• Reviews the role played from the top management to all the personnel of a company, including the essential figure of a coordinator who manages and organizes, taking into consideration that it is a group effort.
• Details the steps required to generate eco-efficient options which must be assessed technically and economically.
• Explains the convenience of acting according to priority criteria and evidencing the benefits achieved through CP.
• Shows how to incorporate the priority that must be given to the assessment, regarding the use of toxic products and its associated risk.

5.2 The CP Programme

5.3 CP Assessment

5.4 Assessment Stages

A systematic CP assessment includes several stages, divided into a number of tasks [58], [59], [60], [61], [62], [63]. It consists basically of the following stages and contents:

1. Assessment Preparation
   • A clear statement of top management commitment and their support of the assessment

     It is essential for the management to clearly state its commitment to the process in order to guarantee the success of the CP assessment. Particularly in companies with a complex organization, it is up to the top management to involve all the groups that are potentially implied. Only when the top management clearly shows a positive disposition to implement CP measures, can it be guaranteed that the different organization levels will also feel committed to the programme.

   • Definition of final and partial objectives

     The objectives sought from the assessment must be developed in detail. Their definition may require specific participation from the personnel in the different areas of its implementation. Objectives are defined taking into consideration environmental legislation and current degree of compliance, technology used in the production processes, benchmarking information related to the products manufactured, human capacity available and imperative market requirements.

   • Organization of the assessment team

     The assessment team must incorporate members from all the functions involved and can also include an external expert who can provide his experience in other assessments and not be influenced by the routine of always working on the same installation. During the assessment period, it will be necessary to count on the participation of the operators at every level, because their continual contact with the processes makes them a source of good ideas for improvement. If the company includes a quality department, it should also be involved in the analysis, to foresee possible customer answers to any changes that may affect the real (or perceived) quality of the product. The preparation also considers the difficulties and barriers that can arise when implementing opportunities, as well as the solutions to these problems.

2. Review of Process Documentation
   • Review of the process steps and units and their diagrams, including in end-of-pipe waste stream treatments.

     The process diagrams are the representation of the transformation of raw materials into products, that include the different units and main equipments, such as the source, circulation and destination of the products, byproducts and waste streams originating from the main transformation or other process operations, including internal recirculations and waste stream treatments (figure 5.1). It is necessary to check if the process diagrams available in the files, reflect the current situation and are complete. If there are none, graphic diagrams of the process must be drawn with field data.

     Figure 5.1 Process Diagram

     
   • Identification of raw material, water and energy inputs

     All raw material and ancillary material inputs must be identified, including water and energy, and their position in the process diagram. Flow rates and material loads must also be determined, as well as the amounts accumulated in the period chosen, in order to calculate the balances.

   • Identification of process, product and byproduct outputs

     As for the inputs, all process outputs must be identified in any form:

     • products
     • byproducts
     • waste streams
     • potentially hazardous waste streams
     • recycled to an external process
   • Identification of the final destination

     The final destination of waste streams is identified (to external recycling, landfill, etc.), their characteristics and if they comply with acceptable limits at the destination point, as well as possible liability of the producer and external waste manager.

   • Determination of the initial levels of internal recycling, external recycling and reuse

     The initial levels of material recovery will allow to complete the process analysis and compare it with the end situation after the CP implementation. The flow diagram and mass balances must include material recirculations, as closed loops within the same process. The materials recycled in an external process will be computed as an output. Reused materials are usually computed twice: once as a material output and then as an input.

   • Identify which stream should be given priority

     CP, like waste minimization, particularly requires reducing, and if possible eliminating, all waste streams containing toxic or hazardous substances. Streams with a larger volume of pollutants or less efficient operations should be given priority.

3. Verify the information available with the field data
   • Carrying out a field inspection

     A field inspection is a first opportunity to inspect the operating conditions, maintenance level and cleanliness of the installations. It enables verification of the information obtained from files, diagrams and data sheets, in particular with regard to potentially hazardous waste streams.

   • Checking data on file and completing them with real data

     Field inspections of the information on process operation and instrumentation allow to check and complete the data on file. Sampling and analyses will enable comparison of the information available on file with the reality of the process.

4. Analysis of Process Balances and Yields
   • Completing material and energy balances

     Balances of material and energy are carried out on the process units, groups of equipment or separate equipment, to verify the consistency of the data available or to obtain any data that may be missing. If the process is continuous and stable over time, a balance can be carried out of the most suitable period-such as a 24 hour-period for example. If the process is not stationary over time, it will be more difficult and the analyst will have to be an expert. Some simultaneous readings of inputs and outputs, without taking into consideration the residence time, will very likely lead to a false interpretation. In batch processes, the balance is made on a complete cycle or load. If possible, it is repeated several times and assessments are made on the average.

     ∑ material input = ∑ material output

     (without accumulation)

     ∑ energy input = ∑ energy output

   • Assessing the efficiency of material and energy use

     The balances carried out on equipment in which some kind of mass or energy transfer occurs, and particularly when chemical transformations are carried out, enable the determination of the real yields of the individual processes, diagnose process or equipment efficiency and determine the reason for a lack of efficiency.

   • Carrying out exergy analyses and thermodynamic (pinch)

     These techniques, unlike the energy balance that is based on the first principle of thermodynamics, apply the second principle and the analysis of heat transfer networks which allow to determine how far away the process is from the practical energy efficiency limits.

     ∑ energy input = ∑ energy output

     ∑ exergy input ≠ ∑ exergy output

   • Checking the potential for waste stream segregation

     Many of the problems of CP or secondary stream treatments can find an easier solution in an individualized treatment. In many cases, mixing leads to waste streams of more difficult treatment. Two individual waste streams could probably be treated more easily. An inert flow mixed with a toxic flow automatically becomes a toxic flow of larger volume.

5. Identification of Opportunities and Technical Assessment
   • Identifying which options are most obvious

     Some of the options identified in the previous stages, will obviously be implemented straight away, particularly those that only involve a change in management, whereas others can also be technically disregarded immediately.

   • Identifying other options that are technically justifiable

     Between the obvious options and those that can be disregarded, there is a group of options that requires a more in depth technical and economical analysis before deciding if its implementation is suitable or not. Generally, this will require a meeting with the experts. Ideas can also be obtained from other sources such as suppliers, particularly when the options include a very specialized technological element. Options which imply a change of equipment must guarantee their availability, reliability and maintenance before they are implemented. The operators may require additional training. If additional amounts of utility services (water, steam, etc.) are required, their availability must be checked. If potential changes in product quality are expected, customer acceptance must be verified. If the productivity of the installation may vary, the changes must appear reflected in the calculations of the economic assessment.

   • Developing long-term alternatives

     Many potential options are not included in the group of presently implementable options due to economic or technological reasons. Options that are not a priority or an immediately selected target will be included in the CP programme and the best time for their future implementation will be decided.

6. Risk Assessment
   • Assessing and comparing risks linked to the presence of toxic substances

     One of the goals of CP is to minimize production risks from toxic substances that intervene or are incorporated in the process (as well as any other hazards that are included in specific studies). Ideally, the evaluation of alternative product synthesis methods, aside from raw material and energy consumptions, will include a comprehensive assessment of the toxicity, persistence and bioaccumulation of all the reagents, products and waste streams for the options evaluated (case study).

7. Economic Evaluation [7]
   • Determining current costs and anticipating future costs

     An appropriate selection of options requires completing the technical analysis with an economic evaluation. For economic evaluations, the investments required and the present operating costs are determined; however, it is also convenient to foresee costs for future disposal.

   • Carrying out financial and economic feasibility studies

     According to the economic criteria foreseen by the management (investment payback period, internal rate of return, present net value, interest rate of money, etc.) the economic feasibility studies are carried out of options that are technically justifiable. Additionally, other aspects that are difficult to quantify are considered, such as civil or criminal liability, and image improvement. An economic evaluation completes the technical study after which decisions are made and priorities assigned.

   • Determining implementation priorities

     Establishing implementation priorities is one of the most important tasks, particularly when economic resources are limited. The order of priorities determined can be discussed with the assessment team, bearing in mind:

     • legal limits authorized for all types of emissions,
     • potential risks,
     • amounts of waste originated,
     • reuse potential,
     • costs of waste treatment or disposal,
     • resources available.
8. Plan of Action
   • Preparing a report with conclusions

     The results of the assessments must be documented and reported to the top management, who will authorize the improvements. The report will serve to check the results at a later date.

   • Designing a plan of action

     The plan of action must be prepared carefully, as for any other project of new implementation. The technical data and human and economic resources required are established.

   • Obtaining sources of funding

     Although some of the options are mainly of management improvement and do not require economic resources, others will require an initial investment. Usually, their implementation must compete with other operating requirements.

   • Implementing options

     The implementation of changes must be carried out as effectively as any other project.

   • Checking

     Once the changes have been implemented and the plant is operating, the correct implementation and the improvements obtained must be checked. New consumptions, waste production, productivity, product quality, costs, etc. must be appropriately verified.

   • Measuring progress

     The benefits obtained from the different options implemented must be quantified and the improvement reported to the management, to confirm its advantages and ratify/implement the CP programme.

   • Reassessment if required

     Exceptionally, it may be necessary to readjust the progression forecasts. Whether it is negative or more positive than expected, the experience obtained will need to be gathered for future options.

5.5 Case Study: Risk Assessment Linked to Toxic Substances

5.6 Application to the Evaluation of Options

6.1 Objective

Each sector has its own prevention at the source options that are linked to the industry-specific technology; however, there are a series of options that are common to most industrial sectors. This chapter details the main CP options at different stages of the production cycle, which include:

• good Practices that all industrial facilities must follow;
• process operations, from the loading and transfer of raw materials to the unloading of products;
• maintenance of equipments and installations;
• the switch from one material to less toxic materials;
• more specific aspects such as the selection of alternative solvents.

6.2 Good Environmental Practices

Best Environmental Practices (BEPs) are a set of measures that are easily applicable to an industry and allow to improve its environmental performance. These are often a good first step towards promoting environmental awareness in a company, before going on to implement CP. programmes. Some generic GEPs can be determined that can be applied to any industry, or others can be defined for a specific industrial sector, although every company should design its own BEPs catalogue according to its particular circumstances.

There are several ways that can lead to determining a BEPs programme and they will depend partly on the coverage and the measures considered most important for the company, sector or institution.

A simple methodology is proposed for companies who wish to elaborate their own specific BEPs, programme, by proceeding in stages

In their Manual on Design and Application of a Programme of Best Environmental Practices (BEPs) in Industry[68], the Government of Catalonia's Department of the Environment and Housing proposes four TIMES (as in a musical composition) for the drawing up of a BEPs programme.

A simple methodology is proposed for companies who wish to elaborate their own specific BEPs programme, by proceeding in stages.

Another example of Good Housekeeping Practices (GHPs) is found in MedClean file no. 18, on pollution prevention in the dairy industry in Egypt.

6.3 CP in Process and Maintenance Areas

Potential improvements in the process and maintenance areas affect the procedures and the instructions, the people and the facilities [69], [70], [71], [72]. Some of the recommendations are common to all the sectors and processes (including the BEPs), but each sector has its own recommendations that are more or less specific to the process.

6.4 CP in Supplies Management

Supplies management, including purchase of materials and warehouse management activities (inventories), offers waste reduction options that do not generally require any investment or just a minimum investment [75]. A good management system can reduce the volume of stocks and therefore the necessary investment, as well as the storage space required. Storage criteria are usually determined according to criteria that may ignore the environmental factor, and also the economic advantages involved. A problem that is associated to the management of supplies is packaging, which is a source of waste streams.

Nowadays, the importance of customer-supplier relationships is well known as well as the role that the purchasing personnel plays in CP [69], [70], [76], [77]. Within the growing relationship of the customer-supplier chain, some production processes have implemented just-in-time (JIT) systems aimed at reducing, and even eliminating, intermediate storage. This is an ideal situation although in many processes, the lack of guarantee for compliance with JIT systems can lead to all sorts of problems such as stops in a continuous process, and negative consequences which override benefits expected in theory. Therefore, before implementing a JIT system, a complete study should be carried out of the associated benefits and risks.

6.5 Changes in Materials

6.5.4 Use of Solvents

Solvents are substances of general use in many different industries and applications:

• Steam degreasing for cleaning of plastic or metal parts
• Dry cleaning of garments
• Cold cleaning of parts and equipments
• Manufacture and application of paints and inks
• Extraction processes in the food industry
• Manufacture and use of adhesives
• Manufacture of chemical products
• Manufacture of pharmaceutical products
• Printing processes.

It was understood that a solvent was an organic liquid of rapid evaporation at room temperature, with emission of volatile organic compounds (VOC). Today we also refer to aqueous and semi-aqueous solvents.

In order to avoid or reduce negative environmental impacts that are linked to the use of solvents, a major part of CP in some industries incorporates the eco-efficient management of solvents (figure 6.1) [81].

A solvent management system includes the following:

• Inventory of the types, applications and amounts consumed in the company
• What cost they represent
• Emission sources and capture or destruction systems
• Measurement and quantification of emissions and retentions
• Situation in relation to the regulation
• Updating of records
• Assessment of improvement options
• Selection of appropriate options

Figura 6.1 System of dissolvent management (ref: Main directorate of Environmental Quality of the Department of Medio.ambiente and House of the Generalitat de Catalunya).

The management of solvents is a process to improve the understanding on how and why a company uses solvents and how it can control and reduce its consumption of solvents and associated VOC emissions. Following are some improvement operations:

• A switch to aqueous solvents [82], [83]
• A switch to other organic solvents [84]
• Improved use and control of emissions [85]
• Improved capture of emissions from tanks and equipment
• Internal recycling [86]
• External recycling

A structured and systematic management system can be part of a CP programme, a separate activity or part of a complete EMS. For many companies, the increasing cost of solvents is as good a reason for implementing CP as for complying with environmental requirements that are more and more restrictive with VOCs.

MedClean file no. 30 presents a specific case in which trichloroethylene was eliminated from metal parts production, through its replacement with a non-toxic water-based cleaner.

6.6 Case Study: Non-Standard CP Solutions

In the implementation of CP the manuals do not always offer solutions that are standard or that can be applied directly. It is often necessary to find original solutions or adopt decisions that are not at all simple. The evaluator needs to have a general knowledge of the methodology for solving problems and adopting decisions, applicable to CP, the same as for any other area of technology management. He can, for instance, adopt the system proposed by Edward Deming for the industrial quality area, that consists of the following steps: Planning, Acting, Checking and Reviewing (PACR). This system is also applied to the planning of EMS (chapter 3).

6.7 Activities

7.1 Objective

The chemical industry typically operates around a reactor, the key element of chemical processes, in which the molecules are transformed into other molecules according to a well defined stoichiometry. The modern chemical industry is partially linked to the oil industry, highly present in a number of Mediterranean countries, This linkage is used to increase the added value and improving the economic cost effectiveness of exportations. In fact, the unit processes of oil refining are the same as in the chemical industry, even more specific for a certain goal. The relevance in the Mediterranean region of the fertilizer production industry must also be mentioned, as well as the tradition of other industries such as the tanning and the textile finishing industries. Many other industrial sectors include chemical transformations in their technology, that are integrated in their particular manufacturing processes. Due to its complexity, economic value and environmental impact, the chemical industry has been the subject of many studies to improve its eco-efficiency.

This chapter:

• Describes how the concept of eco-efficiency and CP are being introduced in research and development laboratories, under terms such as green, benign or sustainable chemistry.
• Describes the conceptual levels or hierarchies of unit processes making up the continuous and batch processes.
• Shows how to focus the research of CP options, starting by the chemical reaction, a typical stage of this industry that requires specialized scientific and technological knowledge.
• Describes the case of batch processes, more specific to SMEs, and the appropriate methodology for CP identification.

7.2 The Chemical Industry in the Modern World

It is difficult to conceive today's world without the chemical industry. Its contribution was essential for the progress of modern society and to improve the quality of life, and provides work, either directly or indirectly, to a considerable percentage of the population.

However, the benefits of this industry have been trivialized. On the other hand, the growing production that initially ignored environmental issues, has made evident the unwanted secondary effects of the production systems adopted. The need to correct its impacts and the interest in the sector to regain a favourable image, has led this sector to anticipate the implementation of eco-efficient measures. For many years, references can be found in chemical industry publications, introducing prevention at the source and minimization as preferred initiatives for the prevention of environmental impacts, and viewing waste streams as a clear sign of loss of cost effectiveness [42], [43], [44], [45].

Before confronting the environmental problems, the chemical industry had already been forced to solve its industrial safety and health problems, that were often associated with environmental problems. Therefore, this sector has a multiple and additional interest in CP, as well as an interest in the conservation and efficient use of materials and energy, of which the chemical industry is a large consumer.

7.3 7.3 Chemical Processes

Chemical processes combine different types of unit operations (described in many basic operations and chemical reaction engineering manuals).

7.4 The Origin of Environmental Impacts

Chemical reactions do not often take place in one direction only, from one molecule to another. Atoms and activated radicals can generally be combined in more than one way, in so-called parallel or sequential reactions. The result is the formation of byproducts along with the desired product. When the byproducts have no application, they become residues (table 7.1).

Therefore, it is necessary to seek a way to increase their material efficiency, understood as the relationship between the sum of products and the sum of raw and auxiliary materials introduced in the process, and prevent process inefficiency conditions (table 7.2).

Material efficiency (the opposite of the material intensity, or raw material consumption per unit of product) varies widely depending on the industrial segment (table 7.3) involved.

The chemical industry has many environmental impacts:

• It uses a large number of catalysts often made from heavy metals which along with other auxiliary materials used in processes of absorption, ion exchange, filtration or drying aids, etc. and secondary products from the reactions, sludges from water treatments, polluted packaging and a number of others, leads to a wide range of solid waste.
• Wastewaters also originate from a variety of sources that often require complete physiochemical treatments, prior to the biological treatments, to prevent the toxicity affecting for microorganisms.
• Other non-aqueous waste liquids, such as solvents and lubricants, require specific treatments for the fractions that cannot be recycled.
• Specific gaseous emissions from the process are combined with fugitive emissions in joints and other points, and other secondary emissions, such as those produced from wastewater treatments.

Some environmental impacts of global importance, caused by the chemical industry, are receiving particular treatments. Such is the case of:

• the substitution of chlorofluorocarbons (CFC) due to their impact on the ozone layer,
• acid rain specifically linked to combustion processes,
• and the potential climatic change associated with the production of carbon dioxide and its greenhouse effect that is mainly, although not exclusively, due to the burning of non-renewable fossil resources.

The complexity of the integrated treatment of all sorts of emissions from the chemical industry, favours the introduction of eco-efficiency, implemented relatively easily by large corporations. This very complexity has made it difficult for SMEs to advance in this sector, and the CP methodology offers them an appropriate way to progress.

7.5 Green Chemistry

The name of green chemistry has probably gained the most adepts when referring to the development of new product synthesis [97], [98], [99], [100] which take into consideration the environmental issue from the first research level of new processes. Green chemistry, also known as benign chemistry, or sustainable chemistry, aims to develop forms of synthesis that apply, whenever possible:

• the use of renewable raw materials
• a minimal use of toxic materials
• good yield and selectivity in transformations
• maximum valuation of all products and byproducts
• material recyclability.

The principles of green chemistry are detailed in table 7.4

The implementation of the optimization concept, either from experience or using mathematical approach, had been easily introduced in process engineering as an almost essential design tool. However, the characteristics of chemical science in the laboratory did not make the optimization of the synthesis method too easy. In research laboratories, the focus was on obtaining a molecule through a reasonably economical method, without giving the importance required from byproducts in transformations.

Increasingly, aware of the environmental implications of the synthesis method, and of the advantages and disadvantages they can represent for a company with regard to its competitors, applied research centres have adopted the new philosophy of designing processes and chemical products aimed at reducing material use and/or eliminating waste generation, while increasing health and safety in all the production stages.

7.6 Hierarchical Methods in Process Design

The configuration of a chemical process is finally decided in the design stage. Several methods are suggested that are actually not very different from one another and establish a hierarchy of decisions aimed at developing a logical selection approach of possible options. The hierarchical methods start by braking down the design into smaller sections, which are then treated sequentially.

The first method of hierarchic design was proposed by Douglas [102] and divided the complex process synthesis, proceeding according to the following levels of decision:

• Level 1 Continuous versus batch process
• Level 2 Input/output system of the flowsheet
• Level 3 Considerations of the reactor and recycle structure
• Level 4 Separation system specifications
• Level 4a Vapour recovery system
• Level 4b Liquid recovery system
• Level 5 Heat exchanger network

One of the various alternatives suggested to modify or increase the process synthesis proposed by Douglas is the onion diagram [103] by Smith and Petela (Figure 7.1), that analyzes, in concentric layers from the centre outwards, the following components: reactor, separation and recycling, heat exchanger network and utilities.

Figure 7.1 Onion Diagram

7.7 Transformation in the Chemical Reactor

Many chemical transformations do not lead to a simple product. Along with the main reaction, serial and/or parallel reactions occur that produce secondary substances, that become byproducts or waste. Research is therefore aimed at finding optimal conditions of reactor, temperature, residence time, catalyst, etc. to achieve:

1. efficient raw material conversion
2. good selectivity in the production of the most interesting substances

Five potential sources of byproduct formation and/or waste streams (according to their possible use or rejection) in the chemical reactors, can be distinguished:

• The production of byproducts or waste streams parallel to the main reaction (table 7.5)

  A + B → P (Product) + S (Byproduct/Waste stream)

• Secondary series reactions from the main product, that produce residual byproducts (table 7.6)

  A + B → Product

  P → S (Byproduct/Waste stream)

• Low conversion and for some reason, impossibility to recirculate unreacted raw material
• Impurities in the raw materials that become waste or can react to produce additional byproducts/waste streams
• Degraded catalysts from inappropriate operation, without possibility of recycling.

Performance improvement and the reduction of residual byproducts has been widely studied. Several manuals [104], [105] and [106] offer detailed analyses of these possibilities. Assessment starts by identifying the determining factors of the reactions [107], [108].

Table 7.5 Reactor Conditions which Minimize the Formation of Byproduct for Parallel Reactions

Table 7.6 Reactor Conditions which Minimize By-Product Formation in Series Reactions

Then the principles of engineering science must be applied to:

• Improve Conversion

  To improve conversion, the following can be considered:

  • Use reagent surplus.
  • Remove product, or one of the byproducts, continuously during the reaction, for example by vaporizing it from the liquid phase.
  • Carry out the reaction in stages with separation of the product, or one of the products, between stages.
  • If during the reaction the number of overall moles is increased, the addition of an inert gas in reactions in gas phase, or of an inert solvent in reactions in liquid phase, increases the conversion in the equilibrium (inversely, its presence decreases the conversion when the number of moles is reduced).
  • In endothermic reactions, the temperature must be as high as it is possible for other factors, in order to increase the conversion. In the case of exothermic reactions, the temperature must be as low as is possibly compatible with the velocity of the reaction.
  • In reactions in gas phase, if the reaction decreases the number of overall moles, maximum pressure must be used to operate, bearing in mind the implications to safety and the additional cost of equipments and operation. If the number of moles is increased, ideally the pressure should be decreased as the reaction advances, either by reducing the absolute pressure or by introducing a diluent inert.

  When the later separation and recirculation of the unreacted raw material poses no problem, it may be preferable not to worry too much about the degree of conversion, although it must be borne in mind that a higher conversion will increase separation efficiency while decreasing its cost.

  Due to its toxicity, pesticide production is a particularly important case in waste reduction and the improvement of production yield. An example of improvement achieved in chemical processing is the case of a herbicide plant in Croatia, where significant improvements were achieved, as described MedClean file no. 12

• Select the Appropriate Reactor

  When selecting the reactor (figure 7.2) the following should be considered:

  • In the stirred batch reactor (SBR) and the piston flow reactor (PFR or tubular) ideally all the materials have the same residence time.
  • In the continuous stirred tank reactor (CSTR) there is a wide distribution of the residence time. It may be advantageous for the feed to be diluted straight after it is introduced in the reactor.
  • The behaviour of several serial CSTRs resemble the behaviour of a PFR.

  Figure 7.2 Types of Reactor

  
• Analyse optimum conditions for parallel and series reactions

  In parallel reactions that give a product (P) and a byproduct or residue (S):

  • In the case of a single raw material (A) to increase selectivity, encouraging the formation of the desired product, it is necessary to take into consideration the kinetic coefficients and the order of the competing reactions and to take advantage of the differences in the most favourable direction.
  • Kinetic coefficients can be modified favourably with a proper usage of catalysts or of the activation energy of the reactions(E).

  • When there are two reacting raw materials (A + B) feeds can be combined to make a semi-discontinuous process;

    • In the case of a stirred tank loading one of the materials right at the beginning whereas the other is fed gradually (figure 7.2 d),
    • In the case of a tubular reactor one material can be fed at the input mouth whereas the other is fed at intermediate points of the piping (figure 7.2 e),
    • Of making use of similar behaviour in serial CSTRs in which one of the materials is completely loaded in the first reactor and advances through the whole series, whereas the other material is partially loaded in each separate reactor of the series (figure 7.2 f)

  In series reactions:

  • The ideal residence time must be found. If it is too short, the conversion may be very low. If it is too long, the product may decompose excessively into byproducts. In order to prevent decomposition, a low product concentration must be maintained
• Apply Conditions Aimed at Improving Selectivity

  The following can improve selectivity:

  • using feed surplus,
  • if the formation of byproduct is reversible and reduces the number of moles, increasing the concentration of inerts; if the number of moles increases, reducing the concentration of inerts,
  • separating the product as the reaction occurs,
  • recycling byproducts in the reactor.

7.8 Use of Catalysts

Similarly, green chemistry has also set its goal on catalysis [109], [110]. Catalysts play an increasingly important role in improving the selectivity of reactions and can be the most important factor for the new approach for substance synthesis. The interest is particularly in catalyzed reactions in the heterogeneous phase, such as in the case of a solid catalyst in reacting gases, because an additional advantage is that the catalyst does not generally require a separation stage to recover it.

The ideal catalyst would be perfectly selective and not require solvents. Although it is impossible to reach an ideal state, there can be an asymptotic approach. Aside from the imperfections in the selectivity and need for solvents, there is also a problem of progressive disactivation of the catalysis.

Another advance related to catalytic reactions is the use of water instead of organic solvents. Water is a good coordination liquid for many catalytic materials. Many reactions (Dies-Alder, carbonylations, alkylations and polymerizations) can occur in an aqueous base. The only negative aspect is that metallic catalysts are not water soluble, although here too there is progress as catalysts can be joined to hydrophilic binders which stabilize their presence in the solution.

Reaction engineering has also enabled to control catalytic reactions through a technology combining reactor and catalyst. Therefore, if for example reaction temperatures wish to be adjusted within specific margins that are thermodynamically favourable to the desired reaction, fluidized bed catalysts can be used to improve flow distribution and heat transfer.

7.9 Separation Processes

Process changes must take into account any reaction improvements together with the separation processes. The separation, as selectively as possible, of products and byproducts, unwanted waste streams and materials that were not transformed in the reaction stage, have a considerable effect on processes eco-efficiency. Aside from producing products of the quality required, they facilitate direct recirculation or segregation of streams for recycling, recovery or treatment. An optimum reaction-separation combination should be carried out.

There are many CP measures that can be implemented, such as distillation, absorption, etc. and in the same way that the reaction is a typical stage of the chemical industry, separation processes have many applications in other industrial sectors. For example, solvent separation and recovery are as useful in the chemical industry as in surface treatments that use solvents for degreasing.

The search for more selective equipment and better automatic controls, multiple product separation sequences (figure 7.3), waste stream segregation, the markets for byproducts and external recycling are part of other options that are found in the improvement of chemical processes [107].

Figure 7.3 Alternatives of Separation after the Reaction A+B → P+S+(A)

7.10 Case Study: Batch Processes

Batch processes are more typical of SMEs because they are applied in many fine chemistry and pharmaceutical chemistry industries. The steps to follow in CP assessment of an existing batch-operated process are practically the same as the steps to follow when designing a new process [111], [112].

The adaptation of the Douglas proposal to a batch process is [20]:

• Level 1: Analysis of the input/output structure

  The first level identifies process feeds, basic and secondary reactions, expected conversions and selectivity of reactions, and waste streams generated. The following CP options are proposed for assessment for the first level:

  • Problems of waste streams generated by the chemistry of the reaction
  • Problems generated by used catalysts
  • Possible additive and solvent changes to prevent the generation of a waste product
  • Impurities present in feeds that can originate waste streams
  • Possibility of using some of the by-products in later reactor loadings
• Level 2: Analysis of the reactor-recycle design

  The second level concentrates on the reactor, considering the various operating stages: loading, heating, reaction and unloading of reactor. Following are some common questions that may arise in the assessment:

  • Status of reactor (open/closed) during loading,
  • Loss of material in open status
  • Order in which the reagents are added and how it affects the emission potential
  • Effects of solution heat on additional losses
  • Use of surplus reagent
  • Potential equilibrium shift of a reaction
  • How to achieve a complete reaction
  • How to minimize byproduct formation
  • Recirculación de algunas de las corrientes,
  • Recirculation of some of the streams
  • Point towards which recirculation must be directed
  • Use of reflux
  • Potential solvent emissions through the air vents during a reaction
  • Need for cooling prior to unloading.
  • Level 2a Reactor loading
  • Level 2b Heating
  • Level 2c Reaction
  • Level 2d Reactor unloading
• Level 3: Analysis of the separation system

  The third level is to decide which type of separation can be used and whether it will be carried out directly in the reactor or in a separate tank. The following considerations are common to each option:

  • Operation of continuous or batch separation system
  • Physical properties of materials and how it will affect the selection of the separation process
  • Auxiliary material required, such as solvents
  • Additional supply of energy required
  • Use of membrane technologies
  • Effluents as a result of the separation process
• Level 4: Analysis of energy integration

  The fourth level analyses the thermal process integration. In batch processes, there is an additional complication due to the fact that the hot and cold streams occur at different times during the process. A tank can be included to store heat although it will require additional equipment and lead to a loss of flexibility. Following are some considerations for this level:

  • Availability of hot and cold streams simultaneously during the cycle
  • Areas using or producing high level energy
  • Limitations in heat transfer efficiency due to temperature gradients
  • Possibility of lowering the temperature of heat supplied
  • Types of energy used and considering if it is the most suitable
  • Potential improvement of the transfer coefficient
• Level 5: Analysis of cleaning and programming

  The fifth level is specific of batch processes because there can be a significant amount of waste produced during cleaning, or an appropriate programming may be missing for the manufacture of various products in the same installation. The following points should be considered:

  • Colvents required for cleaning
  • Number of washes necessary with the method foreseen
  • Use of cleaning solvents as a load in the following process
  • Possible implementation in some form of counterflow
  • Possible usage more than once of the cleaning agent, or its regeneration.

7.11 Activities

8.1 Objective

Until recently, water saving had not been given enough attention by manufacturers. In the industrialization process, water was considered a very low cost resource when compared with other raw materials. When it became obvious that it was a limited resource-this is more evident in the Mediterranean region- that manufacturing processes depend largely on water, and that the cost of quality water was increasing, measures for resource conservation and reuse were developed.

This chapter:

• Emphasizes the particular relevance of water in the Mediterranean region.
• Reviews the basic concepts of industrial water management and the distribution of its industrial uses.
• Describes some possible water conservation and water reuse approaches.
• Describes the case of the surface treatment industry to offer some examples of efficient water saving systems in the rinsing stages of parts that would otherwise consume large amounts of water.

8.2 The Importance of Water in the Mediterranean

The shortage of fresh water in the Mediterranean region is a very important issue in industrial planning and a relevant factor to be considered when promoting and implementating a CP programme in Mediterranean countries.

Table 8.1 shows the relationship between uses and available resources [113]. This table points out very significant figures, aimed at understanding the relevance of proper water management at all levels. In some countries, the yearly consumption of water exceeds their renewable resources --such is the case of Libya, Egypt and Israel-- whereas other countries use very large percentages without reaching the extreme situation of the first mentioned. The deficits must be balanced with the use of non-renewable fossil waters or by implementing energy consuming technologies.

In the Mediterranean region, sustainable water management in the industry and its efficient use, is a task that requires particular consideration when diagnosing CP opportunities, including monographic actions directed exclusively at water. Indeed, some agents in the Mediterranean region involved in Cleaner Production, already consider water as a priority.

8.3 Water Management in Industrial Sectors

8.4 Industrial Use of Water

Water is used industrially for many different applications that vary with regards to both the quantity and the quality required for the processes. Depending on the application, the volumes used go from a few litres to many cubic metres per hour: [115], [116]

Used in large volumes

Uses in moderate volumes

Uses in lesser volumes

Potable service

The quality required varies largely according to use. Very few applications require a very high water quality. Applications often use water of higher quality than is strictly required. The different quality requirements offer the possibility of carrying out water recovery and cascade uses by progressively using the partially contaminated water for applications with lower requirements, although it is usually necessary to implement a partial treatment technology before reuse. Only waters that cannot be recycled should be sent to the sewer after being treatment, if they do not meet the quality standards for discharge.

8.5 Types of Wastewater

Wastewaters generated in the processes can be classified according to their origin and quality. The quality is particularly linked to the use it has been given. It is often advisable to segregate wastewaters in order to give them a more efficient treatment or a specific destination. Concentrated waters can make contaminant recovery economically viable. This may be the case with chromium from tanning wastewaters or heavy metals from surface treatment systems. Some of the segregated waters are also easier to treat for reuse rather than having to purify them further for their discharge to the receiving medium in appropriate conditions.

A plant can start segregating their waters according to their origin:

1. Waters from manufacturing and process units
   • Waters which have been used in the main reactions and transformations
   • Product cleaning waters
   • Water from recipient cleaning and rinsing
2. Water from utilities services and support operations
   • Boiler blowdown
   • Cooling tower blowdown
   • Gas scrubbing blowdown
   • Water from ejectors and vacuum pumps
   • Treated wastewaters
   • General housekeeping water
3. Stonewater
   • Contaminated
   • Non contaminated.

8.6 Reduction of Industrial Consumptions

The three main forms of reducing the volume of water used are:

• Elimination of losses
• Minimization of use in individual applications
• Water reuse (8.7)

Water use does not always correspond to real requirements There are many water conservation options in manufacturing plants, that can be identified and evaluated, starting with measurements without having to resort to experts, although undoubtedly the contribution of an expert may increase the possibilities of conservation.

Following are a few examples of water conservation options in processes and in utility services:

• Control flow rates by using restrictions or automatic systems
• Carry out cleaning with efficient systems such as:
  • high pressure water jets instead of using deep tanks,
  • using counter-current or cascade systems for washing and rinsing,
  • control conductivity of aqueous baths before discharge in surface coatings.
• In utility water systems, the following measures can be adopted:
  • install automatic shutoff systems on drinking fountains,
  • install limiting flow rate controllers in showers,
  • limit flushing in toilets.
• Change from aqueous-based systems to dry systems, such as:
  • using filters to retain particles in gas instead of washing with scrubbers,
  • switch to air cooling instead of water cooling systems.

8.7 Water Reuse

The alternatives for reuse that can be given to wastewaters depend on their characteristics, the quality of the water required, and on technical and economical assessment criteria. Therefore, information must be obtained regarding:

• the type of contaminants (organic, inorganic, etc) and their concentrations,
• the variability in quantity and quality of the waters to be treated,
• whether the contaminants are dissolved or in suspension,
• if the dissolved contaminant is gas, solid or liquid,
• the yields obtained with each technology,
• all the investments and costs linked to recovery,
• operation and maintenance requirements, and
• the type and quantity of waste left after treatment.

Providing a too drastic change in quality is not sought, important water savings can be obtained with reuse measures. Wastewaters of complex contamination should not be treated to a high level of quality. When waters from different sources are mixed together, the compatibility of the substances contained in the water must be checked.

Water consumption is very important in some industries, such as sugar. For this reason reuse actions, such as those carried out in a Moroccan factory in the sector, described inMedClean file no. 9, achieve reductions in water consumption of 60%.

The formation of scale, corrosion and deposits due to microbiological growth are common problems that arise from the use of reused water, which will require controlling. Other problems are specific to each industrial sector. For example, in the manufacture of paper, its colour may be affected by the presence of iron or manganese.

8.8 Recovery Technologies

Many recovery technologies are the same as the technologies used in typical wastewater treatments (table 8.2). Large flow rate treatment processes such as sedimentation, softening or biological treatment, have relatively low purifying costs per cubic metre of treated water. Other processes are more selective and for specific applications, with higher unitary costs that depend on the degree of purity sought [116], [117], [118].

An example of water recovery after passing through an evaporator is described in MedClean file no. 28, in a Spanish mechanical parts firm.

Table 8.2 Technologies Applicable in Contaminated Water Treatment

Technology	Soluble inorganic contaminants	Soluble organic contaminants	Suspended contaminants	Biological contaminants
Stripping with steam, air, etc.
Ion exchange
Active carbon
Centrifugation
Crystallisation
Electro-dialysis
Evaporation, distillation
Solvent extraction
Filtration
Flotation
Biological oxidation
Chemical oxidation
Precipitation
Sedimentation (coagulation, flocculation)
Membrane separation (osmosis, ultra-filtration)

8.9 Membrane Technology

Among the different technologies developed for water recycling and reuse, membrane technology is particularly important. Membrane filtration allows to separate the components through polymer membranes giving a permeate and a concentrate. The permeate is the fraction that passes through the semi-permeable membrane. The concentrate, that follows the tangential flow on the membrane, entrains, with part of the fluid, the components that cannot go through the membrane.

The degree of concentration is associated with the distribution of pollutants between purified water and concentrated water (a 4x factor, for example, corresponds to a 75/25 permeate/concentrate distribution relation). The effectiveness of the separation depends on the size and other factors relating to the molecule.

8.10 Case Study: Surface Treatments

Understanding the advantages of CP requires bringing students into contact with real situations and presenting evidence that is interesting enough to reinforce their interest. Many sectorial publications are aimed at covering these aspects. One of the CP/RAC publications studies the surface treatment industry [119]. Likewise, MedClean file no. 2, "Cleaner production in a company in the electroplating bath sector through adopting Good Housekeeping Practices (GHPs) and process changes", describes a selection of measures applied and the results obtained.

The metal surface coating industry generates very complex and toxic wastewaters, with heavy metal ions, cyanides and solvent residues, which require physicochemical treatments. In this sector, some of the best CP opportunities are precisely of water saving during the rinsing of parts after coating.

After each coating stage, rinsing is required to eliminate the excess metal carried over from the baths, making it necessary to use large quantities of water that are proportional to the production [119], [120], [121]. This is one of the processes that offers the best opportunity for water saving and an excellent example of the advantages of counter-current rinsing, as compared with single rinsing and parallel rinsing.

8.10.1 Single and Multiple Rinsing Without Addition of Fresh Water

Single rinsing is carried out in a tank after the coating process without any other water than that originally contained in the tank. No fresh water is added during the rinses and it is assumed that the mixture in the tank is perfect. If the initial concentration (in contaminant) of the rinse water is zero, then the concentration in the rinsing tank after n immersions is

where

v = volume carried over in each immersion (litres)

V = volume of rinsing tank

C₀ = initial concentration of contaminant solution carried over from the coating

C_n = concentration in the rinsing tank after n immersions (mg/litre)

8.10.2 Rinsing in a Single Tank with Addition of a Constant Fresh Water Flow Rate (Q)

q = v·n/t·Q

where

n =number of carry overs in a time t

Q = Constant flow rate of fresh water added to the tank and discharged by overflowing

After a certain time a stabilized concentration is reached

8.10.3 Rinsing In n Series Tanks, each with Parallel Addition of an Equal Fresh Water Flow Rate (Q)

Concentration at the outlet of tank n is

The fresh water flow fed into each tank to obtain a specific concentration of contaminant C_n is

When q<<Q approx. the usual form is obtained

And the total flow rate of fresh water consumed is

8.10.4 Counter-current Rinsing with a Single Supply of Fresh Water Flow (Q)

Concentration of contaminant in tank n, and in the carry over after going through n series tanks is

Flow rate Q required when q<<Q is

8.11 Activities

Exercise 2

1. The first activity proposed is to reach the equations for the four types of rinsing systems presented: (8.10.1 to 8.10.4)

   The solution to this exercise is available.

   1. Single and Multiple Rinsing without Addition of Fresh Water

      

      There is a single rinse without addition of fresh water and it is assumed that the mixture in the tank is perfect. If the initial contaminant concentration of the rinse water is zero, and

      v = volume carried over in each immersion (litres)

      V = volume in rinse tank

      C₀ = initial concentration of the contaminant solution carried over from the coating bath (mg/litre)

      C_n = concentration in the rinse tank after n immersions (mg/litre)

      The balance of contaminant for the 1st rinsing operation is

      

      and the contaminant concentration is

      

      The balance for the 2nd rinsing operation is

      

      and the contaminant concentration is

      

      Then, concentration in the rinse tank after n immersions is

      

   2. Rinse in a Single Tank with Addition of a Constant Fresh Water Flow Rate

      The carry over for each immersion (v) is assimilated to a constant flow rate q,

      q = v.n/t. Q

      where n = number of carry overs in a time tQ =constant fresh water flow rate added to the tank and discharged by overflowing

      

      In transitory regime, concentration after a time t is

      

      After some time a stabilized concentration is obtained

      

   3. Series Rinsing in n Tanks, each with the Addition of a Constant Fresh Water Flow Rate Q

      

      In stationary state, concentration at the:

      • Outlet of the 1st tank (previous problem)

        

      • Outlet of 2nd tank

        

      • Lastly, concentration at the outlet of tank n is

        

      The fresh water flow rate fed to each tank to achieve a specific concentration of contaminant C_n is

      

      when q<<Q, approx. the regular form is obtained

      

      Overall fresh water flow rate used, is

      

   4. Counter-current Rinse with a Single Supply of Fresh Water Flow Rate Q

      

      In the case of 2 stationary tanks(C₃= 0):

      Balance in 1st tank

      

      Balance in 2nd tank

      

      By substituting and operating, the following is reached:

      

      The contaminant concentration in tank n, and in the carry overs after going through n series tanks, is

      

      Flow rate Q required when q<<Q is

      

2. The second activity is to determine the water use and average concentrations of effluents corresponding to the cases mentioned, when a stationary operation is reached and carry over from the process tank is 1 litre/minute at a concentration of 100,000 mg/litre:

   Types of rinse	Water use (litres/minute)	Average effluent concentration (mg/l)
   Single
   2-stage parallel
   3-stage parallel
   4-stage parallel
   2-stage counter-current
   3-stage counter-current
   4-stage counter-current

The solution of this exercise is available

Example of a Solution for 2-Stage Parallel Rinsing

The balance is started at the outlet of the last (2nd) tank

Q = 99 l/min and tank

Total water use = n. Q = 2.99 = 198 l/min

Outlet from 1st tank

Average effluent concentration = (99x1000 + 99x10)/198 = 505 mg/l

Table of Solutions

Types of rinse	Water use (litres/minute)	Average effluent concentration (mg/l)
Single	9.999	10
2-stage parallel	198	505
3-stage parallel	62	1.622
4-stage parallel	36	2.777
2-stage counter-current	100	1000
3-stage counter-current	22	4.641
4-stage counter-current	10	9.999

9.1 Objective

Industrial plants use several forms of energy (electricity, steam...) as well as different equipments. The interest in energy saving became a priority due to economic reasons following the energy crisis in 1973, long before CP was organized. In fact, some years later the energy experience helped to rapidly develop a CP methodology. Although the concern for energy saving declined, it has been renewed with CP programmes due to its relevance in climate change.

This chapter includes:

• a description of the energy system,
• a review of the history of energy audits,
• an analysis of the main tools for energy assessment,
• a description of some of the applications of energy assessments.

9.2 Energy Eco-efficiency

In the mid seventies, the price of energy increased a lot more than the price of industrial materials and equipment. This justified many investments in energy-efficient equipment. In the new economic framework, a movement began for the conservation of energy and the introduction of improvements in energy efficiency. Later, the relative price of energy declined again, along with the interest for improving energy management.

Some Mediterranean countries are large producers of fossil energy and obtain a major part of their income in the trade balance from fuel exportations. This fact should not lead them to boost a domestic industry based on low cost fuel, because a disincentivation of energy efficiency can end up outdoing any theoretic benefits by causing a cascade effect on the whole industrial fabric. In any case, eco-efficiency should not be discouraged, it should be promoted as a component of industrial culture of any country.

CP has always considered energy as one more element of eco-efficiency in transformation. And, the probability of a climate change, principally linked to carbon dioxide emissions from the burning of fossil fuels, has renewed the interest in energy efficiency and conservation and the implementation of renewable energies. The positive effect of renewable energies on climate change is reinforced indirectly by a reduction of CFCs, which is closely linked to energy consuming equipment.

9.3 Energy Systems

An energy system consists of various sub-systems that can be studied and optimized separately, although they will eventually be assessed jointly. The heterogeneity of the energy system starts with the different forms of energy present (kinetic, potential, chemical, etc.), but the most commonly used in all industries are heat and electric energy. Heat energy is applied in many different ways: as hot water, pressurized steam and thermal oil; it is also associated with the transformation process of some materials such as sensible heat from melted metal or vaporization heat in the steam phase of a distillation tower.

In an energy system, there are [122] (figure 9.1):

1. Different forms of energy inputs (fuel, electricity, steam, renewable, etc.)
2. Internal conversions from one form of energy to another
3. The distribution systems that take the energy to the consumption points
4. Utilisation points and their different destination uses
5. Energy recovery systems
6. Energy outputs or losses

Figure 9.1 Main Subsystems of the Energy System

9.4 The Energy Audit

Over time, the price of energy is subject to changing trends that are quite different from the price variations of raw materials. Therefore, an energy system that is designed optimally for certain conditions may not adapt well to others. Technologies also improve, seeking higher efficiencies. The energy audit (incorrectly called an audit as it is more like a diagnosis or assessment of the energy system) can be conducted as an isolated exercise, although it is preferable if it is part of a permanent energy management programme, a CP programme, or an element of a well-implemented EMS. These are all good occasions to adapt to the changing circumstances .

The methodology for energy programme auditing [122], [123], [124] is similar to carrying out a CP diagnosis or assessment (section 5). It requires complete support from the management, assigning of responsibility to a real promoter and the participation of all the parts interested, including the system operators. The audit team can start by verifying if there are any previous studies carried out on the energy system. The first step for an assessment will be to obtain relevant information regarding the system, which will allow to set goals and establish progress indicators.

The physical system audit is then planned and conducted in various phases. Document studies must be accompanied by on-site visits and checks that will help the energy experts to identify possible discrepancies between the actual situation and the printed information, as well as to identify other opportunities based on a series of practical rules which any expert has assimilated over time. This phase includes:

• The energy system technical data collection

  This includes data on the original design and any possible modifications of the system; lists of equipment, specifications; the best presently available technique applicable, etc.

• Analysis of subsystems and individual system components [125]

  Each subsystem and component (cogeneration, steam generation, cooling system, etc.) is studied separately, before assessing the overall system. The efficiency of each separate equipment, insulations, ducts, etc., is compared with the original data and the presently best available techniques that do not imply too high a cost.

• Checking the energy balances of processes

  The energy conservation principle is applied (1st law of thermodynamics) to carry out the energy balances and check the destination and losses from the energy inputs. These checks are more complex when transformation processes are involved such as: combustions, chemical reactions, etc.

• Analysis of exergy [126], [127]

  Exergy is the maximum amount of work that a system can provide until achieving a balance with its environment. Exergy results from the analysis made according to the second law of thermodynamics (for example, 1 MJ of heat at 1, 00ºC is not the same as 1MJ at 200ºC). The work we can recover from a gas at 1,000ºC is much higher than that recovered at 200ºC). The efficiency losses indicated by the exergy analysis can differ greatly from those determined by a simple heat balance.

  Example of Energy and Exergy Losses in a Coal-based Thermoelectric Plant

  Component	Energy loss (%)	Exergy loss (%)
  Steam generator	9	49
  Turbines	0	4
  Condenser	47	1,5
  Others	3	5,5

• "Pinch" analysis (thermodynamic adjustment of heat networks) [128], [129]

  The Pinchtechnique assesses optimum heat recovery in industrial plants with parallel cooling and heating requirements. The technique is supplemented with a thermo-economic assessment. In complex heat exchange networks this technique has led to improving energy savings up to 40%.

• Use of practical rules

  Energy experts have a series of practical rules acquired from experience, that allow them to easily identify the points at which good results can be expected by implementing measures for process improvement. For example, flue gases that come out of a stack at 200ºC is clearly a possible heat recovery option.

• Diagnosis of the energy system

  In view of the technical opportunities and economic assessments, the range of conservation opportunities or energy efficiency improvement can be determined, to decide which options will be chosen for their implementation.

• Programme Implementation

  As with any CP programme, the implementation usually starts with opportunities offering better economic advantages that are easily justifiable to top management.

At present, many firms have carried out some sort of energy-saving exercise when the energy cost is a relevant part of the overall production cost. However, permanent economic and technological change factors still allow the identification of new opportunities. For enterprises that have not granted special attention to the energy issue, the success level is usually equivalent to other CP aspects.

9.5 Options to Reduce Energy Consumption

There are many different options to improve energy management in each energy subsystem [125], [129].

Some options focus on making the design of process equipments more efficient and reducing their energy requirements (in the distillation for example). Other options use auxiliary systems that allow recovery of the energy that would otherwise be discharged in the environment (economizers, thermo-compression), or manage to extract energy from the environment with a supplementary contribution (heat pumps).

Management improvement is often achieved by paying attention to the overall heat system (transfer networks), or through an optimum combination of the different forms of energy (electricity and heat in cogeneration systems) for manufacture requirements. Another option is to consider and study jointly the requirements of plants located in the same area.

The following subsystems offer some of the best options:

• Combustions: furnaces and boilers
  • Control excess air at optimum value and CO in flue gas.
  • Install air economizers and preheaters to lower flue gas temperature.
  • Adjust burner periodically.
• Heat exchangers
  • Maximum recovery of residual heat.
  • Use pinch techniques to set recovery limits.
  • Determine an optimum cleaning programme and the best way to implement it.
  • Consider using low Δt exchangers.
  • Promote turbulence to increase transfer coefficients.
• Fluid separation subsystems
  • Optimize heat integration between feeds and products.
  • Use efficient packings.
  • Optimize column feeding point.
  • And many other specific options.
• Process auxiliary systems
  • Optimize the steam/electric power balance.
  • Reduce losses in steam blowoffs.
  • Use optimum cogeneration system.
  • Replace internal parts of inefficient cooling towers.
  • Optimize cooling water circuits.
  • Use heat pumps.
  • Consider using thermo-compression systems.
• Electrical subsystem
  • Use high efficiency motors.
  • Replace with variable-speed motors when operating below capacity.
  • Check the system's power factor.
  • Test for possible lowering of peak consumptions.
  • Consider using generators to prevent peaks.
• Lighting
  • Replace with efficient systems.
  • Activate lighting in work area only.
• Check the efficiency of pumps, compressors, fans, etc.
• Check refractory of insulations and refractories

  A firm in the Croatian food sector has achieved a significant reduction in heat losses through insulating the pipes carrying hot fluids MedClean file no. 54, Reduction of energy losses in the transportation pipes"). At the same time, the reduction in energy consumption represents a reduction in CO2 emissions and a positive effect on climate change prevention.

• Check control systems and instruments

9.6 Case Study: the Brewing Industry

9.6.1 Manufacturing Process

Brewing (figure 9.2) is based on an old fermentation process. In the past, brewing involved using large amounts of water and energy (table 9.1). With the new techniques available, consumption per production unit can be considerably reduced. Many modern installations are already including these advances, and they are also used as upgrading options for existing facilities [130]. In the process, there are several instances in which CP energy-saving measures can be implemented.

Malt is the basic raw material in a brewery. However, malting is generally considered an industry in itself. To manufacture malt, barley is dampened and left to germinate. Then it is dried with hot air and the germs are separated. To dry, air is blown during 40 hours at a temperature of 60ºC to 85ºC. During this stage, the humidity drops from 45% to 4% in order to maintain the grain in condition and facilitate transport. Drying is a process that uses large amounts of energy.

Then the malt is ready for brewing, and although a general method is followed, it varies from one factory to another. First the malt is ground and cooked with water to produce the beer wort. Then the wort is filtered to separate the insoluble matter and it is roasted by adding hops, that lends it its typical bitterness. During roasting, 6-12% of the wort evaporates. If the vapour is not recovered, there will be a loss of energy and foul odours. The simplest form to recover the vapour is to use it in other applications and for cleaning. However, it can also be reused in the same operation after going through a recompression stage that will increase its temperature. The solid waste pulp separated during the filtration, can be given as fresh feed to cattle that are nearby the facilities, or it can be pressed and dried.

The boiled wort is cooled and clarified before yeast is added for fermenting. The new yeast formed in excess must be separated and stabilised to be recovered as feed. After the first fermentation, the wort is submitted to centrifugation and cooled at a controlled temperature for storage. These cooling operations are an important part of the cooling requirements of the brewing industry.

For shipping, before bottling, the beer is filtered to clarify it, additives are added and it is carbonated with CO₂, recovered from the fermentations. Much of the beer is bottled, although some of it is put in barrels. In order to ensure its stability, the beer that is in storage is sent through a sterile filtering or pasteurisation process.

Figure 9.2 Diagram of Brewing

Table 9.1 Typical Inputs and Outputs to Obtain 1 hl. of Beer

		Inefficient	Efficient
Input	Malt and other	18	15
	Energy MJ	350	150
	Electricity kWh	20	8-12
	Water hl	20	5
Output	By-products
	Grains used	17	14
	Yeast	3	3
	Wastewaters
	Volume hl	18,5	3,5
	BOD	1,2	0,8

9.6.3 Energy Applications

The use of energy in the manufacture of beer is high, although the present technologies offer several options of improving the energy yield. In an energy assessment, the implementation of three specific techniques of energy conservation can be considered, beyond a simple heat exchanger:

1. Co-generation systems are very effective when a large supply of heat is required and the electric energy from the system can also be sold.
2. The heat pump has many application options within a specific temperature range. It extracts heat from a cold source: air or water at room temperature and delivers it at 55-80ºC using an appropriate carrier fluid in an inverse Rankine or Carnot cycle.
3. Another alternative is the mechanic compression of water steam when this fluid can be recovered with its energy content.

In every case, the process economy varies depending on the relative prices of gas or fuel and of electricity. In the malt production stage, the kiln drying process consumes large amounts of energy. One possibility would be to use the hot gas from a cogeneration system for drying. This solution has applications with a payback period of 2-3 years [135].

Exist two alternative options for drying malt with energy recovery. One of them with a simple heat recovery using an exchanger (figure 9.3), in which the additional heat required to complete the drying is obtained from the auxiliary boiler.

Figure 9.3 Malt Drying Installation

The other option would be the use of a heat pump (figure 9.4) to increase thermal efficiency. This device allows a reduction in the energy consumption specific to the drying process of 705 kWh, in a traditional installation with a gas boiler, by up to 213 kWh per tonne of malt [136].

Figure 9.4 Malt Drying Installation Using a Heat Pump

The same heat pump cycle can be applied to the cooling circuit [137]. In this case, energy is extracted at low temperature and released at room temperature. The cooling requirements are around 35 MJ per Hl. of beer.

Roasting is another operation that uses a large amount of energy. There are two alternatives for heat recovery: roasting with single exchanger with intermediate storage (figure 9.5), and using an ejector or mechanical steam compression system (figure 9.6) [130], [138]. The typical heating solution requires consuming 737 kWh per tonne of steam, whereas mechanical compression reduces consumption to 52 kWh [138].

Figure 9.5 Heat Recovery through Preheating

Figure 9.6 Heat Recovery through Mechanic Steam Compression

The pinch technique has also been applied to the brewing industry, to integrate all the heating and cooling loads [139].

9.7 Activities

Exercise 2

Application: Water and Energy Saving in an Industrial Washing Machine

The following is an exercise proposed as a practical example in which there is possibility of water and energy saving. It is the case of a firm specializing in industrial laundry that washes around 500 tons of laundry yearly, divided in 200 working days. The washing process used, that is technically similar to the system used in a household washing machine, is particularly polluting. The water used for each separate operation of the washing process is used once and discharged to the sewer system. Initially, there is no energy recovered.

The operation is very inefficient from a viewpoint of consumption of resources. And, the trend is to increase the price of water and a consumption tax has been established. There is also a requirement for treating water before its discharge.

The washing programme is sequential and includes the following process cycles and conditions:

Soaking	40 ºC	soft water	8 litres water/kg of laundry
Prewash	40 ºC	soft water	8 litres water/kg of laundry
Washing	80 ºC	soft water	5 litres water/kg of laundry
1. Rinsing	40 ºC	soft water	6 litres water/kg of laundry
2. Rinsing	cold	soft water	6 litres water/kg of laundry
3. Rinsing	cold	soft water	6 litres water/kg of laundry
4. Rinsing	cold	soft water	6 litres water/kg of laundry
5. Rinsing	cold	hard water	6 litres water/kg of laundry

Except for the last rinse, the water used is soft water, to guarantee the quality of the process.

The relation between litres of water and kilograms of laundry indicated is the amount in litres of water that there must be in the machine (partly soaked up by the clothes and partly free) per kilo of laundry. It can be calculated that the laundry soak up 2.5 litres of water/kg of laundry are after the machine is emptied. Spinning will help to drain off one more litre of water per kilo of laundry.

In the prewash and the wash, a detergent is used that is part soap part bleach. The soap has the following composition:

fatty acid	40 %
non-ionic surfactants	5 %
alkylbenzene sulphonic acid	5 %
isopropylic alcohol	10 %
optical brightener	0,1 %
water	up to 100 %

The bleach is a 30% weight sodium hypochlorite solution

In the rinsing, the bleaching agent used is a sodium hypochlorite solution with a 12.5% weight of active chlorine, and the neutralizer is a 40% weight acetic acid solution.

The following amounts are added:

Prewash	15 g soap/dry laundry
	15 g bleach/dry laundry
Wash	20 g soap/kg of dry laundry
	15 g bleach/kg of dry laundry
First rinse	2 g chlorine/kg of dry laundry
Fifth rinse	2 g acetic acid/kg of dry laundry

The prewash water that is discharged has a pH of 9.5, and the washing water a pH of 10,5.

The energy used for heating the water is obtained from overheated steam at 120 ºC.

Suggest approaches for water and energy saving (independently, the added cleaning agents should be adapted).

The solution of this exercise is available

Possible Solutions to be Implemented in an Industrial Washing Machine

10.1 Objective

Some of the applications of CP show results that are immediate or visible in the short term. Other options could possibly be applied in the future when the environmental costs are internalised, financial criteria are applied that are more sensitive to sustainable development, or technologies are improved. In order to stimulate new applications it is important to keep a record of the progress achieved with the implementation of CP measures. However, aside from being a means of introducing environmental management in industrial enterprises, it also prepares them for innovative options and future competitiveness. To achieve sustainable development, a transition period will be required during which the necessary changes are carried out. These changes must be capable of originating sufficient technological development to attain the efficiency factor X that is considered necessary in the use of resources.

This chapter describes:

• The measure of progress in the implementation of CP.
• The role of CP as a form of innovation.
• The changes required to achieve sustainable development.
• The Factor X by which eco-efficiency must be multiplied.
• The relation between knowledge and technological policy to determine the future guidelines of innovative research.

10.2 The Measure of Progress

There are many proposals concerning how to measure the environmental progress achieved with CP, as an index or as indicators. It is always preferable to use a quantitative form. At the same time, it is also advisable, whenever possible, to measure the actual economic benefits of CP. The group of measures can then be compared to the forecasts made in the preliminary assessments and judge whether the forecasts made were realistic. The measures of progress should become part of the integrated business management indicators [140].

The results can be expressed in absolute values or relative indexes. As absolute values they can take on a series of values measured on a yearly basis and the comparison between values that are consecutive in time can then be used to determine the measure of progress. Alternatively, standardised indexes can be used that give the measure of progress by themselves.

The reduction index, RI, is calculated according to the following equation

where:

Gb = quantity processed or generated in the base year

Gn = quantity processed or generated in the current reporting year

Pb = product produced in the base year

Pn = product produced in the current reporting year

The Pn/Pb relation is also the activity index on the production facility

Other indexes of specific internal use can also be used, such as:

• Yield of raw materials in a transformation

  Yield % = 100 * 100Product/Feed

• Recovery efficiency in a separation unit

  Efficiency=Recovery/Feed

• Waste index

  Waste index = ∑ Waste streams/∑ Feeds

10.3 CP as an Innovative Process

During the 20th century, the prosperity of the industrial society was partly due to an intensive scientific and technological research process, which was followed by the innovative process. Basic scientific research (the generation of new knowledge) and applied scientific research (the solving of specific technical problems) are the basis for building a cumulative, organized and systematic body of knowledge. This knowledge opens the door to new findings (discovering something that already existed but was unknown to us) and inventions (inventing something that did not exist). The technological innovation process is fuelled by these findings and discoveries and develops activities that enable them to be put into practice. In order to judge CP as precursory of innovation in enterprises, need it only be highlighted that CP is also "fuelled by findings and discoveries and develops activities that allow to put them into practice".

Innovation is a necessary complement for the successful introduction of technological novelty in the society. Some innovations can be considered as simply incremental, whereas others are radical. Companies that opt for CP tend to be vocationally innovative and adopt CP as an additional business element of technological progress, or even as an initiator to put their vocation into practice.

The Mediterranean countries have unequal capacities, in the short term, of participating in the development of radical innovations, but when it comes to incremental innovations their competency is almost the same, particularly when many of the incremental innovations involve adapting technologies to the specific conditions of each country. CP contributes to development and benefits from local experiences that take into account the differentiating facts such as the availability of material resources and qualified labour, environmental conditions, etc.

10.4 The Transition to a Sustainable Development

When the advances achieved with CP are described with satisfaction, the present situation must be put into perspective. The transition from the current society to a society focusing on sustainable development requires changes that are much more significant than the incremental changes provided by CP, or any other tools focusing on producing short term improvements. During the coming decades, incremental improvements will not be sufficient to ensure an economic growth that has to be combined with environmental and social improvements.

The changes required to achieve a sustainable society are of a different scale and will need to be included in a transition process [141], [142], [143]. The possibility of optimizing this process of transition towards a sustainable development will depend largely on the availability of appropriate technologies, as well as on an innovative strategy and conditions that must necessarily focus on sustainability at all levels (international, local, governmental, scientific and social). The necessary transformations in the industrial field will affect most sectors (table 10.1) [142]. Therefore, to stay on this innovative course (table 10.2) it will be particularly useful if the companies have previously acquired a certain capacity for changing, through implementing CP.

This process of transition involves many factors and as many actors. Its success will require the creation of transition prospects shared between parties of different characteristics. Therefore, a transition management system with a view of the future will be necessary as well as an efficient communication system between the parties. The following example (figure 10.1) of a transition system to create an energy supply system that does not increase atmospheric CO₂ will require implementing various technologies. However, for the productive actors to consider them as commercial opportunities, some decisive institutional actions will also be necessary such as, subsidies, fiscal measures, regulations, etc.) [144].

Figure 10.1 The Transition from a Fossil to a Neutral Fuel Supply

Figura 10.2 Transición desde el origen de la P+L a la innovación

In the Mediterranean countries where CP plays an important role in incremental innovation, its cooperation with the national or university centres for applied technology, contributing with the on site experience achieved in the industry, should act as a stimulating element to help these research centres increase their possibilities of success in participating in radical innovation.

10.5 The Social Dimension of Technological Change

The first efforts to improve the environment were aimed at applying end-of-pipe cleaning technologies instead of applying cleaner technologies. To correct this trend, a movement sprung up in the seventies under the concept of appropriate technology, called "technology adapted to the psychosocial and biophysical context prevailing in a particular location and period" [141]. This movement proved to be a failure, as it did not take into account the social dimension of the technological change, required to have a crucial influence on the redesigning of the technological systems. The reluctance of many engineers to apply alternative design technologies is partly explained by the technological paradigms.

In circumstances of ordinary technology, the development or technological path is determined by the existing paradigm (figure 10.2). Radical technological innovation often comes up against many companies due to the social changes that may be required (changes in operators' work and skill, the way production is organized, relations with customers and suppliers, etc.). Since decisions must be adopted in situations of conflicting interests, the regulatory and economic instruments applied are rarely strong enough to lead to a technological change of the required magnitude to approach sustainability. However, the very concept of sustainability incorporates the need to harmonise development, environment and social respect.

Figure 10.2 The Technological Path Determined by the Existing Paradigm [141]

10.6 Transition Management

It is difficult to make a strict definition of the framework in which to progress towards transition, but some countries have started a period to assess and analyse the trends and results of actions focusing on sustainable development [143], [144]. As a result, transition management principles can be offered to mark the beginning of the path to a new period of technological innovation:

• Long-term strategy in target setting

  The incentives for environmental innovation are currently focused on optimizing existing systems, often as a result of short and medium term approaches. Some persistent environmental problems (climate change, reduction in non-renewable resources) are almost impossible to solve with the current policies. These problems need a new focus to meet the requirements. In general terms, it is necessary to identify and solve the conflicts between current activities and the future goals of society.

• Integrated strategies for economic, social and ecological aspects

  After restoring the quality of the environment to a reasonable level, an unlimited environmental policy would not be justified should it not integrate economic and social aspects. The strategy should focus on optimizing the integrated system, without neglecting the intensification of environmental improvements, balanced with other strategic aspects.

  
• Composition of transition through projection and retroaction

  One of the main challenges is to connect the current trends with trend changes that can be induced in the short term, after defining a situation required in the long term, which would lead to reorganizing the path to transition. To achieve the goal of a continuous transition, it is advisable to point out as many viable paths as possible in both directions (figure 10.4) and build scenarios of intermediate situations in which the targets of both lines converge.

  Figure 10.4 Diagram of the Two Definition Lines for Future States

  
• Institutional support in its initial stage

  The transition will require changes in the companies. Most companies feel better acting as they always have and it is difficult for them to make changes on their own initiative if they are not convinced that their competitors will also make the change. It will be necessary to induce the industries to invest in sustainable technologies, pointing out the changes in society values and consumer awareness. Although there is always a small percentage of firms that can see the advantages of being the first in making changes, the speed of transition will be set by the whole sector involved. It is positive for governments to support pioneer movements. Subsidy schemes are justified and legitimized by the reasoning that R+D costs are paid by a few actors only, whereas the benefits are gathered by many actors and eventually by the entire society.

• Culture of consultation and cooperation

  This transition process requires a new approach for the production of new technologies. This new approach encourages companies, by using all the instruments available, to start developing technologies according to a new competitive outlook based on future requirements and functionality. Change can be speeded up if the industries participate in the setting of priorities. Aside from being involved in the definition of the future, the cultural change should also include cooperation, provided by setting up networks based on sharing knowledge and actions of common interest.

• Re-engineering the institutional system

  The transition process involves a re-engineering of the institutional and social systems, encouraging the development of new technologies focusing on sustainable development and the implementation of a good combination of all the institutional instruments.

10.7 Change Factor X

A change of the scale described in this chapter can be measured according to a factor X (4,10, or other) [145]. Factor X is the multiplier of process eco-efficiency. In the immediate term, CP is associated with incremental improvements to existing processes. In a second stage of progress, new technologies are implemented that multiply by 4 the efficiency of the current processes. And lastly, sustainable technologies would be achieved reversely, determining first the target to be attained and then how to achieve it (figure 10.5).

Figure 10.5 Temporary Framework for Sustainable Technologies

In a framework of progress such as in figure 10.6, the scientists must identify the signs and evidences of physical and environmental unsustainability through studying the state of the world (with measures, indicators...) at a global and local level. The trends are influenced by the complex biological, geological, physical and chemical cycles of the environment. For each piece of evidence (such as climate change), the environmental strategy needs to establish an inventory of cause-effect relations and assess the degree by which the different causes contribute to the effect studied. This information (indicators of state, trends and causes) must be shared with the social agents.

Figure 10.6 Evolution to the New Sustainable Technologies

To achieve the Factor X change, the current range of management tools and methodologies [146], [147], [148], [149], [150], [151], [152] must evolve and adapt to future requirements; we must be able to surmount new obstacles and introduce the appropriate technological changes in the production system. Future proposals for new technologies should undergo a technological assessment to check their conditions of sustainability.

10.8 Case Study: Technological Policy Instruments

Different outlooks on sustainable development can lead to different types of interventions from governments in the management of the transition process. A review of the different instruments implemented by European countries has allowed to compile the guidelines of potential action [146] for the development of a technological policy based on knowledge. It is up to the governments to adapt the appropriate composition to each country's circumstances, from among the following categories.

11.1 Objectives

In recent years, there has been a growing focus on environmental education with the creation of new degrees in environmental science and engineering, and the introduction of environmentally-based courses in other professional careers (known as curriculum greening). Many academic subjects focus on solving environmental problems through the implementation of end-of.pipe treatments and there is generally little CP content in these disciplines [153] and [154]. However, the university is also the place where the concept and practice of pollution prevention at the source should be taught in order for it to be adopted spontaneously as a future business value. The subject of this chapter is to bring the students as close as possible to real experience in industries. This is done:

• By explaining the exercise of The Ingenuity Factory, used internationally as an introduction to minimization and CP, that can be adapted to all ages.
• When it is difficult to gain access to a plant to practise CP, an alternative that is accessible to everybody is their home kitchen (that can be compared to a factory specialized in cooked foods) in which the relevant CP assessment can be made.
• Carrying out a diagnosis of an experimental laboratory, such as the chemical laboratory of any scientific faculty, and proposing CP measures.
• Using an example of an environmental diagnosis of a school or faculty, that can be compared to a service activity.

11.2 The Ingenuity Factory

11.2.1 Introduction

This exercise was developed by the Minnesota Technical Assistance Program and Waste Reduction Institute for Training and Application Research in the United States and since then it has become part of CP training programmes worldwide, aimed at very different audiences: industrialists, legislators, administrations and generally, anyone interested in the concepts of CP.

The principles of minimization are illustrated by simulating an industrial process. The objective is to initiate the participants in the identification of opportunities leading to the reduction at the source of waste generation and resource consumption. The difficulty with the identification and implementation of minimization measures quite often arises from different circumstances such as the staff's refusal to accept changes, the pressure to which the management is subjected or the difficulty in choosing and justifying changes in the production processes without the necessary information and communication.

Good communication can be as essential as the technical capacity to identify and implement the measures leading to waste minimization. The objective is that once the exercise has been completed, the participants will be able to acknowledge the capacity that everyone has, even in unfamiliar situations, to apply CP principles and identify improvement opportunities and the benefits of formulating the right queries while listening to the appropriate people.

11.2.2 Material Required

Groups of 6-7 persons are organized. Each group will require:

• A work table
• A sheet of paper to position the production plant 1 m² approx.
• Markers and sticky labels
• Plasticine extrusion machines (such as Play-Doh, Fabrica Loca, with the suitable accessories such as a knife, etc.)
• 2 pots of yellow plasticine
• 2 pots of blue plasticine
• 2 pots of any other plasticine colour.

Scales will also be necessary and shared by all the groups.

11.3 The Kitchen Factory

11.4 CP in University Laboratories

11.5 Case Study: Diagnosis of the Faculty