Methods for aggregation and communication of life cycle inventory data within the framework of eco-efficiency analysis - A case study at Akzo Nobel
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Typ
Examensarbete för masterexamen
Master Thesis
Master Thesis
Program
Publicerad
2008
Författare
Borén, Tobias
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
In meeting the needs of a large and growing population with increasing affluence, industry puts a significant stress on the environment. Thus there are demands on the corporate world to decouple economic activity from environmental impact, i.e. to become more eco-efficient. Eco-efficiency analysis (EEA) is a tool that implements the concept of eco-efficiency into the daily operations of a business by integrating Life Cycle Costing (LCC) and Life Cycle Analysis (LCA). These tools help decision makers in making environmentally and economically motivated choices. However, LCA:s can generate life cycle inventory lists of complex environmental data which decision makers often have limited time or knowledge to interpret. Also the economic and environmental indicators need to be combined in a way so as to facilitate sound eco-efficiency comparisons in decision making. Therefore the purpose of this thesis was to investigate methods for aggregation and communication of life cycle inventory data within the framework of eco-efficiency analysis, i.e. weighting methods for aggregation of LCA inventory data, and methods for integration of LCA and LCC data. Seven different weighting methods, and different ways of integrating LCC and LCA data, were applied in an eco-efficiency analysis of a waste water treatment plant at Akzo Nobel Site Stenungsund. In this case study the present process conditions are scrutinized and compared to different scenarios representing other process settings. Furthermore, two established principles for weighting were used to develop a set of weighting indexes adapted to the environmental targets and preferences of the authorities in Stenungsund municipality. The results from the case study indicate that from an eco-efficiency perspective it is not motivated to change the present process conditions. It also shows that different weighting methods generate different results concerning what is the most environmentally benign process setting. This is because different weighting methods are based on different preferences towards nature and society. However, the study also identifies possibilities for case and site specific weighting, i.e. weighting which is adapted to the environmental and institutional context of the study. This proves the weighting to be meaningful in adding information, and providing adequate and easy-to-interpret indicators, to assist in decision processes. The most appropriate way to aggregate LCA and LCC data will depend on the context of the study. What is to be communicated and who is to take part of the information are important aspects. The LCA and LCC data can be kept separate in a two-dimensional index, and be presented in a graph, or they can be combined into a one-dimensional eco-efficiency index by taking the ratio of the two. The study indicates that in general interpretation of a onedimensional index requires more knowledge of the concept of eco-efficiency. This can be a problem when applied in decision making. Simpler to grasp is a two-dimensional graph which communicates the absolute and/or relative effectiveness of different alternatives. A onedimensional index can however complement a two-dimensional index in also communicating the efficiency in terms of a benefit over costs incurred to generate that benefit. Moreover, depending on which interpretation key that is used, the effects of choices at the micro level on the macro level eco-efficiency will vary. For the global community to become more eco-efficient all actors in society need to take responsibility for becoming more ecoefficient in their actions. For corporations this means that it could be wise to measure the ecoefficiency at the corporate level. The measure should then be in the form of a one-dimensional index with e.g. value added on the nominator and environmental impact on the denominator.
Beskrivning
Ämne/nyckelord
Miljöteknik , Environmental engineering