Tools and Methods for Pollution Prevention

Eliminating that activity altogether can prevent man-made pollution from any specific activity. In view of the attendant benefits accrued from human endeavors, this is obviously not a desirable outcome. A somewhat more practical scope of pollution prevention, which offers incremental reduction in pollution, is given by the US Pollution Prevention Act, 1990¹. According to the Act, pollution prevention means “source reduction” and other practices that reduce or eliminate the creation of pollutants through (i) increased efficiency in the use of raw materials, energy, water, or other resources, or (ii) protection of natural resources by conservation. Source reduction in the Act is defined as any practice which (i) reduces the amount of any hazardous substance, pollutant, or contaminant entering any waste stream or otherwise released into the environment prior to recycling, treatment, or disposal; and (ii) reduces the hazards to public health and the environment associated with the release of such substances, pollutants, or contaminants. The National Commission on the Environment (NCE)²gives a more expansive definition of pollution prevention that does include recycling/reuse of material which would otherwise be released as wastes. In essence, pollution prevention is a term that represents realization of pollution reduction resulting from purposeful improvement in the designs of products and processes, rather than definite elimination of pollution. Rational design of products and processes requires appropriate scientific and engineering tools that aid in the analyses of specific situations and comparative cleanliness of competing approaches.Such toohs are only beginning to be developed, and the rest of the chapters in this book contain the dominant and emerging examples.

The Czech Republic is a country with a transforming economy. A specific feature affecting the public attitude about environmental protection is the neighbourhood of developed countries. The paper is based on my personal view on the history and perspectives of environmental protection in the Czech Republic. The role that the chemical and chemical engineering community in the Czech Republic should play in improving environmental protection is discussed.

The European Commission supports the Environmental Action Programme (EAP) for Central and Eastern Europe [1], which offers criteria for identifying critical short-term environmental needs in the region, priority projects dealing with the reform of institutions, laws and policies, and immediate expenditures targeted directly at specific environmental threats.

Many Romanian industrial plants and technologies are either old and inefficient or not well operated. They need to be modernized through process modification; by increases in the efficiency of equipment, operation and maintenance procedures; or by undergoing complete technological change.

Life Cycle Assessment (LCA) is a technical tool to use to identify and evaluate opportunities to reduce the environmental effects associated with a specific product, production process, package, or activity. It has three separate but interrelated components: inventory analysis, impact analysis and improvement analysis. Implementation of opportunities pointed out in the third stage of LCA can be made using pollution prevention techniques.

The paper presents characteristics of the iron and steel industry, a case study of an LCA in a Romanian iron and steel plant, and some resultant pollution prevention measures for the studied system.

Life cycle assessment (LCA), i.e. the systematic analysis and assessment of environmental impacts of a product “from the cradle to the grave,” is a new and emerging tool. On the one hand, it is employed by governments when, for instance, establishing ecolabelling criteria for certain product groups or when defining mandatory re-use or recycling quotas as it has been undertaken in the context of the German packaging ordinance. On the other hand, LCA is increasingly applied by companies for the identification of environmental weak spots in products and processes.¹But how is this tool of environmental management actually applied in practice? To which extent is it embedded in companies’ decision-making processes? Has its use ever yielded environmental improvements? And how can small and medium sized firms be supported in effectively adopting this complex tool? The IÖW has addressed these questions in a number of projects.²This paper provides a summary of the main results of this research.

Although Life Cycle Assessment (LCA) has been developed primarily as a tool for product development and comparison, it has much wider scope. This paper addresses the application of LCA to the selection, design and optimisation of process operations, with examples from the chemical, water and mining sectors. Of particular interest is the problem of reconciling incommensurable environmental impacts - known as the “valuation” problem - in LCA. For optimisation problems, rather than attempting to reduce impacts to a single metric constituting the objective function, the non-inferior (or “Pareto”) surface can be used to define the space within which optimal solutions lie, and thus to provide the basis for implementing environmental improvements in process design and operation.

This work compares the life cycles of returnable and non-returnable beer bottles. The methodology, principles and framework adopted are those proposed by SETAC’s working group. The “Critical Dilution Volume” method is used to evaluate the inventory data and perform the environmental impact assessment. The inventory data was obtained from two Portuguese industries and compared with the BUWAL database. The differences between returnable and one-way beer bottles were analysed and show that recycling of glass bottles provides larger environmental benefits than reuse.

Phosphorus is the nutrient that most often limits growth in freshwater systems. A major part of the Black Sea is critically eutrophic, because there has been an enormous increase in the nutrient load to the Sea in the past 25 years, probably as a consequence of the widespread use of phosphate detergents and fertilisers in the Danube Basin.

The removal of P from detergents is the fastest way to reduce P-discharge into surface water; however all appropriate steps should be taken to encourage industries to develop phosphate substitutes that are harmless to the environment. A simplified LCA study was completed in the frame of the EU PHARE Project on Removal of Phosphate from Detergents in the Danube Basin Countries (Detergent Project). A consortium consisting of SENATOR Consult Ltd. and VITUKI Consult Rt. (Hungary), RIIDHE (Research Institute for Irrigation, Drainage and Hydraulic Engineering, Bulgaria) and WRI (Water Research Institute, Slovakia) was formed specifically for the purposes of this project. In addition to the consortium, experts from the EU member countries and local organisations and experts from the Danube Basin countries worked on the project.

The Detergent Project was funded by the PHARE Programme of the Commission of the European Union on the advice of the Danube Programme Coordination Unit, Vienna. However, the findings, interpretation and conclusions expressed in this paper should not be attributed in any manner to the Commission of the European Union, to the Danube Programme Co-ordination Unit, or to the countries they represent.

The overall objective of the Detergent Project was to support the riparian countries in the Danube Basin to eliminate phosphorous from detergents as soon as technically possible and economically and environmentally justified. The study aimed at providing support for the preparation of integrated, coherent detergent-policy and strategy in the Danube Basin and for the integration of LCA with other tools into processes that aid water quality decision-making, combining environmental life cycle thinking with economic and social decision-making criteria. The countries studied were Germany, Austria, Czech Republic, Slovakia, Slovenia, Croatia, Hungary, Romania, Ukraine, Moldavia and Bulgaria.

According to the objectives of the Detergent Project, those criteria have to be developed for detergents which lead to a reduced environmental impact during their entire life cycle. The criteria were based on the results of a simplified LCA approach. It is apparent that the criteria are of different importance and should be of different weight in the final scoring result.

The results of the environmental impact studies confirmed that the emissions to waste water/water are the most important ones. Whereas the packaging of the detergents is dealing with an impact to soil (dumping sites), air (combustion of packaging waste) and recycling management, the detergent ingredients are solely related to an impact on waste water/water.

It is a result of the current discussion in LCA for laundry detergents that the impact and effects on different environmental compartments should be assessed separately but can be combined to a final result by appropriate assessments. All the environmental loadings that occur during the life-cycle of detergents have to be studied.

Since development and use of Life Cycle Assessment (LCA) methods gained momentum in the beginning of the 1990s, methods have much improved and a lot of experience has been gained in application of the methods. Today, a level of consensus about methodology has been achieved that allows for international standardisation on the frames of the method and on some substantial parts as well.

There has been an increasing recognition that many environmental efforts of the past have succeeded only in transferring pollution from one medium to another — from water to air, or from air to solid waste. It has become clear that more holistic approaches to solving environmental problems are needed. The emphasis on pollution prevention has led those in industry and government to look beyond their own fences at the causes of pollution both upstream and downstream from the production process — during the entire life cycle of products and their constituents.

The Eco-indicator 98 project aims at a complete revision of the Eco-indicator 95 methodology. Like its predecessor, the target is to develop single scores for designers. The method now includes resources and land use. Important improvements are: the use of fate analysis, the much better definition of the damage categories (human health and ecosystem health), using the PAF and DALY concept, and a completely new approach to modelling resources and land use. Perhaps the most fundamental improvement is the management system for value choices. The result of this management system is that there will be three in stead of one indicator. Each version is based on a different cultural perspective. The method should be updated continuously. The author proposes to set up an independent organisation to guide this future development

The paper first addresses the applicability of steady-state mass balance models for evaluating the fate of a chemical in a multi-media environment as part of the process of impact assessment and pollution prevention. It is suggested that such models can be used to deduce concentrations in a variety of environmental compartments, including media such as air, water and foodstuffs, which are important vehicles for chemical exposure to humans and wildlife. The models can be applied both to continuous fluxes of chemicals into the environment (e.g. 100 kg/day of benzene from a petroleum refinery) and to pulses of chemicals associated with the use of functional units within an LCA framework (e.g. 100 g of volatile solvent from a can of paint). An Index for Potential Toxic Impact (IPTI) for comparing pollution prevention alternatives of consumer products and manufacturing processes is presented. The index brings together steady-state emissions or pulse LCA emissions, substance partitioning and persistence properties, inter-media transfer rates, exposure pathways and toxicity in an overall evaluation of potential toxic impacts. The use of the EQC Level III Multi-Media Model for this purpose is illustrated for both flux and pulse discharges in the hope that it may encourage the use of such models for impact assessment and pollution prevention.

An overview of the field of Environmental Impact Assessment is presented. The different types of methods considered in this overview are presented and their key terms and traits are identified. The role of impact assessment in various applications is discussed, along with identification of key questions and issues that need to be addressed.

At present, designing processes is considered necessary as part of sustainable development in the process industries. Energy savings and pollution prevention have become priorities. Thus, it is necessary to place great emphasis on waste minimisation and energy efficiency in the context of good economic performance and good health and safety practices.

An integrated approach to the reduction of toxic waste in pharmaceutical and specialty chemical manufacturing is presented. The approach focuses on fundamental understanding and redesign of the relevant production processes.

Organic solvents are ubiquitous in the reaction and separation steps of pharmaceutical and specialty chemical processes. This typically leads to the formation of nonideal mixtures of solvents, and the resultant difficulties in separating solvent in pure form for recycle due to the presence of azeotropes. Solvent that is not recovered typically becomes toxic waste. This problem is exacerbated by the nature of manufacturing in these industries: large numbers of small volume products, short process development and product life cycles, and the use of multipurpose batch equipment.

The synthetic component of our work observes that the presence of azeotropes imposes a structure on the overall composition space. This space is divided into a series of batch distillation regions, each of which is characterized by a different sequence of cuts achievable. Hence, we can design a stream composition by moving it from one region to another, hopefully identifying more environmentally favourable alternatives. We present a process wide geometric approach that will, given a set of candidate solvents and entrainers, choose solvents and design the mixtures formed in the process to maximize the potential for solvent recovery and recycling, subject to typical constraints such as reaction stoichiometry, solvation of reactions, etc.

Industrial examples illustrating solvent integration internal to a process, and integration across parallel processes in a multi-product facility are presented. In conclusion, outstanding issues and future directions for solvent recovery targeting are discussed.

Pollution prevention is one of the key objectives of a processing facility. Notwithstanding its importance, it must be reconciled with other process objectives such as cost effectiveness, quality assurance, yield enhancement, debottlenecking, safety, and energy conservation. For many years, environmental issues of manufacturing operations have been conveniently isolated and addressed with little or no interaction with the other process objectives. The result has been a widespread adoption of pollution control, strategies that focus primarily on end-of-pipe treatment, in which chemical, biological, and physical processes are applied to terminal,streams to reduce toxicity or magnitude of environmentally undesirable compounds. This approach has enabled engineers to avoid in-plant changes and has, therefore, allowed the development of pollution-control technologies as stand-alone devices that can be used to treat the symptoms without much regard to the root causes within the core processing operations. The result has been in the form of solutions that worked but nonetheless had poor economic indicators. This situation has led to the common misconception that the solution to environmental problems of the process is an economic burden and that objectives of cost effectiveness and benign manufacturing cannot be reconciled.

Chemical process industries including petrochemicals, and plastics are major sources of hazardous wastes. Process simulation models and other design tools allow engineers to design, simulate, and optimize chemical processes. However, there is a critical need to incorporate more environmental considerations into the design of these processes. These environmental objectives have placed additional requirements on process data and models, as well as increased the need for sophisticated simulation technology to quantify the impact of pollution prevention options. Therefore, process design for environmental considerations calls for new methods and models to be incorporated in all phases of process engineering activities, ranging from conception to design to operation. This paper presents the integrated approach to process design for environmental considerations and analyzes the state-of-the-art methods and tools to address the problem of pollution prevention by design.

Computer aided molecular design provides a means for determining molecules or mixtures of molecules (CAMD) having a desirable set of physico-chemical properties. Therefore, it is ideally suited for selection/design of material substitutes in the prevention and/or cure of some pollution problems. Even though CAMD has found useful industrial applications, the application range is restricted because of the limitations on the complexity of the generated molecular structures and on the availability of suitable models for property prediction. In this paper we have combined molecular-level information with the current group contribution based methods in order to open new horizons of applicability and accuracy of CAMD. With our new integrated approach, we have a multi-level method for molecular structure generation and property prediction. The first two levels are macroscopic, while the third and fourth levels are microscopic. The purpose of adding the microscopic representation is that it allows a more thorough analysis of the generated molecules and it provides an interactive feature for generating structural alternatives. With this combined approach, it is now possible to apply CAMD for a large range of problems involving pollution prevention by substitution. Through a case study involving several sub-problems, application of CAMD for solution of typical problems in pollution prevention by substitution is highlighted.

Since the signing of 1987 Montreal Protocol, reducing and eliminating the use of harmful solvents has become an internationally prominent environmental protection mission. Solvent substitution is an effective way to achieve this goal. The Program for Assisting the Replacement of Industrial Solvents, Version 2 (PARIS II) is a Windows-based solvent design tool which can greatly reduce the time and cost required for finding solvent substitutes. It can handle either pure chemical or mixture substitute designs. This paper briefly introduces the theory and methods used in PARIS II and gives two examples of solvent design applications using PARIS II as an illustration.

Material substitution has a long history - illustrating a constant search for new materials that would provide advances in performance and convenience.

Recent interest in pollution prevention (P2) has resulted in development of a host of assessment tools for specific industries. The Manufacturing Environmental Services division of the Great Lakes Manufacturing Technology Center (GLMTC) has been involved in P2 assessment tools development as a part of the NIST (National Institute for Standards and Technology) for the purpose of assisting small and medium-sized companies to improve their competitions while promoting environmentally friendly processes. This paper will review the availability of various tools, their effectiveness, and a road map for their usage. This overview concentrates on P2 tools developed for the metal finishing industry which are aimed in conducting assessments to determine what changes should be made to improve quality, productivity, profitability and overall competitiveness of a manufacturing facility. The paper highlights various types of assessment tools, as well as their applications. In addition, it addresses barriers to successful application of assessment tools. Finally, it discusses recent case studies where significant savings were realized by implementing one of the P2 assessment tools. The paper discusses importance of the tools as building blocks for designing processes that are environmentally friendly and confronts the challenges confronting tools practitioners.

Design engineers and managers make decisions daily that result in various impacts to the environment. Product performance and profitability are historically their central concerns and primary areas of expertise. While many recognize the potential liability and other negative impacts of a decision that is made without consideration for the environment, the ability to include it in the decision process, quantitatively and reproducibly has been lacking. The evaluation of multiple criteria with complex tradeoffs can be a difficult problem, particularly when dealing with diverse criteria such as cost, health, safety, and a myriad of potential environmental impacts.

Over the last several years, under a number of private and public initiatives, tools and methodologies have been developed that show promise for easing the integration of environmental considerations into product and process design decisions. Difficulties with integrating multiple criteria in the decision process have, however, slowed the rigorous inclusion of these tools and methodologies into regular decision processes.

A modified approach of the Analytic Hierarchy Process (AHP) for decisionmaking has been developed. This approach combines quantitative data relevant to the process or product as well as the qualitative priorities of decision-makers on weighing trade-offs and will assist in factoring multiple criteria in everyday decisions.