Roland Clift

The application of life cycle assessment to process optimisation

Abstract One of the main potential uses of life cycle assessment (LCA) in environmental management is for identifying options for environmental improvements of a system in which complete supply chains are considered. The main problem, however, lies in finding the optimum improvement strategies and choosing the best alternative in a decision environment with multiple, and often conflicting, objectives. To aid the decision-making process, this paper proposes the use of multiobjective optimisation (MO), whereby the system is simultaneously optimised on a number of environmental objective functions, defined and quantified through the LCA approach. This results in a Pareto or noninferior surface, with a range of environmental optima, from which the best compromise solution for improving the environmental performance of the system can be chosen. However, system improvements cannot be based solely on environmental considerations and other factors, including socio-economic, must be considered in parallel. This paper also shows that MO coupled with LCA provides a powerful tool for balancing environmental and economic performance, thus enabling the choice of best practicable environmental option (BPEO) and best available technique not entailing excessive cost (BATNEEC). The value of this approach in environmental system analysis lies in providing a set of alternative optimal options for system improvements rather than a single prescriptive solution, which may be optimal but not necessarily appropriate for a particular situation. A decision–aid tool–optimum LCA performance (OLCAP)–has been developed for these purposes. OLCAP is tested and demonstrated by application to a case study of an existing mineral-processing system producing boron products. It is shown that LCA can successfully be combined with optimisation techniques to satisfy both economic and environmental criteria for more sustainable performance of the product system over the whole life cycle.

Life cycle assessment and multiobjective optimisation

Abstract Life cycle assessment (LCA) is a method to identify and quantify the environmental performance of a process or a product from “cradle to grave”. Its main potential in environmental decision-making lies in providing a quantitative basis for assessing potential improvements in environmental performance of a system throughout the life cycle. This paper introduces the use of multiobjective system optimisation in LCA as a tool for identifying and evaluating the best possible options for environmental management of the product system. A life cycle of a system is optimised on a number of environmental objective functions, defined in terms of the usual LCA burden or impact categories, and a range of environmental optima is found on the Pareto or non-inferior surface. As a result, possibilities for improving the environmental performance of the system are identified. Since system improvements cannot be carried out on the basis of environmental LCA only, it is also shown in this paper that the compromise between environmental and economic performance can be found on the non-inferior surface. The value of multiobjective optimisation in system analysis lies in providing a set of alternative options for system improvements rather than a single prescriptive solution, thus enabling the choice of the Best Practicable Environmental Option (BPEO) and Best Available Technique Not Entailing Excessive Cost (BATNEEC). This approach is illustrated by application to a real case study of a system producing five borate products.

Including Carbon Emissions from Deforestation in the Carbon Footprint of Brazilian Beef

Effects of land use changes are starting to be included in estimates of life-cycle greenhouse gas (GHG) emissions, so-called carbon footprints (CFs), from food production. Their omission can lead to serious underestimates, particularly for meat. Here we estimate emissions from the conversion of forest to pasture in the Legal Amazon Region (LAR) of Brazil and present a model to distribute the emissions from deforestation over products and time subsequent to the land use change. Expansion of cattle ranching for beef production is a major cause of deforestation in the LAR. The carbon footprint of beef produced on newly deforested land is estimated at more than 700 kg CO(2)-equivalents per kg carcass weight if direct land use emissions are annualized over 20 years. This is orders of magnitude larger than the figure for beef production on established pasture on non-deforested land. While Brazilian beef exports have originated mainly from areas outside the LAR, i.e. from regions not subject to recent deforestation, we argue that increased production for export has been the key driver of the pasture expansion and deforestation in the LAR during the past decade and this should be reflected in the carbon footprint attributed to beef exports. We conclude that carbon footprint standards must include the more extended effects of land use changes to avoid giving misleading information to policy makers, retailers, and consumers.

The application of Life Cycle Assessment to Integrated Solid Waste Management - Part 1 - Methodology

Integrated Waste Management is one of the holistic approaches to environmental and resource management which are emerging from applying the concept of sustainable development. Assessment of waste m ...

Relationships Between Environmental Impacts and Added Value Along the Supply Chain

Abstract The ecometric approach developed by Unilever for overall business impact assessment (OBIA) is extended to show how environmental impacts and economic value build up along the supply chain of a product. Aggregated data for industrial sectors and specific data for one type of product—mobile telephones—both show the same conclusion: the primary resource industries give rise to environmental impacts disproportionate to the associated added value. This simple result has important implications for the positioning of companies in the supply chain, for the developing economies, and for the re-use and recycling of manufactured goods.

Sustainable Development in Practice: Case Studies for Engineers and Scientists

About the Editors ix List of Contributors xi Preface xiii Part 1 1 The Concept of Sustainable Development and its Practical Implications 3 Slobodan Perdan 2 Measuring Sustainable Development: An Overview 26 Slobodan Perdan and Adisa Azapagic 3 Assessing Environmental Sustainability: Life Cycle Thinking and Life Cycle Assessment 56 Adisa Azapagic Part 2 4 Translating the Principles of Sustainable Development into Business Practice: An Application in the Mining and Minerals Sector 83 Adisa Azapagic and Slobodan Perdan 5 Climate Change and Policy: The Case of Germany 117 Wolfram Krewitt and Hans Muller-Steinhagen 6 Sustainability Assessment of Biofuels 142 Adisa Azapagic and Heinz Stichnothe 7 Scenario Building and Uncertainties: Options for Energy Sources 170 Richard Darton 8 Fuel Cells in Stationary Applications: Energy for the Future? 189 Martin Pehnt 9 Sustainability of Nuclear Power 211 Adisa Azapagic and Slobodan Perdan 10 Municipal Solid Waste Management: Recovering Energy from Waste 261 Adisa Azapagic 11 Sustainability Issues in Food Provisioning Systems 326 Adisa Azapagic, Heinz Stichnothe and Namy Espinoza-Orias 12 Providing Sustainable Sanitation 348 Richard Fenner and Amparo Flores 13 Sustainable Process Design: The Case of Vinyl Chloride Monomer (VCM) 374 Adisa Azapagic 14 Urban Sustainability: The Case of Transport 420 Slobodan Perdan and Adisa Azapagic 15 Aviation and its Response to Environmental Pressure 449 Alice Bows and Kevin Anderson 16 Health Impact Assessment of Urban Pollution 467 Zaid Chalabi and Tony Fletcher 17 Social and Ethical Dimensions of Sustainable Development: Mining in Kakadu National Park 483 Slobodan Perdan Index 511

On the two-phase theory of fluidization

The distribution of gas flow between bubbles and the dense phase in a fludized bed is considered. By deriving general equations for gas and solids continuity in a freely-bubbling fluidized bed, the possible contributions to the invisible gas flow are formulated. It is shown that the gross assumptions inherent in “two-phase theories” of fluidization are not justified. Measurements of visible bubble flow and bubble volume fraction can give nothing more than estimates for the gas flow through the two phases.

Life cycle assessment of energy from waste via anaerobic digestion: A UK case study

Particularly in the UK, there is potential for use of large-scale anaerobic digestion (AD) plants to treat food waste, possibly along with other organic wastes, to produce biogas. This paper presents the results of a life cycle assessment to compare the environmental impacts of AD with energy and organic fertiliser production against two alternative approaches: incineration with energy production by CHP and landfill with electricity production. In particular the paper investigates the dependency of the results on some specific assumptions and key process parameters. The input Life Cycle Inventory data are specific to the Greater London area, UK. Anaerobic digestion emerges as the best treatment option in terms of total CO2 and total SO2 saved, when energy and organic fertiliser substitute non-renewable electricity, heat and inorganic fertiliser. For photochemical ozone and nutrient enrichment potentials, AD is the second option while incineration is shown to be the most environmentally friendly solution. The robustness of the model is investigated with a sensitivity analysis. The most critical assumption concerns the quantity and quality of the energy substituted by the biogas production. Two key issues affect the development and deployment of future anaerobic digestion plants: maximising the electricity produced by the CHP unit fuelled by biogas and to defining the future energy scenario in which the plant will be embedded.

Teaching sustainable development to engineering students

Sustainable development is a complex concept which concerns a wide range of social, techno‐economic and environmental issues. Without addressing all these dimensions, teaching of sustainable development would not be complete. Therefore, taught modules and teaching materials for engineering students should include not only technological analysis and economic evaluation, but also environmental and social considerations. This paper outlines the way in which a multidisciplinary approach to teaching sustainability has been embodied in learning programmes and activities in engineering at the University of Surrey, UK. More specifically, it describes a project to develop a comprehensive IT‐based learning resource comprising a set of multidisciplinary case studies and support material in order to aid engineering students in understanding the concepts inherent in sustainability and how solutions can be developed.

A methodology for assessing soil quantity and quality in life cycle assessment

Changes resulting from economic activities in the quantity and quality of soil in a system under analysis are important considerations in a life cycle assessment (LCA) study because they affect the safeguard subjects of resources and future agricultural productivity. In the approach proposed here, soil is treated as an ancillary which may leave the system in a form different from that at entry. Relevant factors describing possible changes in the soil include: soil mass, nutrients, weeds and weed seeds, pathogens, nutrients, salts, pH, organic matter, and soil texture and structure. Many of the factors can be included by modelling the effects of infrequent activities benefitting the crop(s) under analysis. Three additional factors require separate assessment: changes in the mass of soil, its organic matter content, and soil compaction. Taken together, these approaches provide an integrated assessment method capable of accounting for the overall impacts of agricultural production on soil.