Life Cycle Assessment (LCA)– A Means to Optimise the Structure of Sustainable Industry

Sustainable development will become a forceful driver of re-structuring industry in the 21st century. As a comprehensive development concept, sustainability will influence all aspects of industrial processes, from their raw material base to their size and location to their interaction with each other and the environment and finally to their economic and social implications. This tall task requires completely new approaches to decision support. The methodology for the decision making process within the framework of sustainable development is still far from complete. LCA will, however, almost certainly become part of this process. This contribution explores the capacity of LCA for (and the requirements for LCA methods necessary to) solve questions of optimal process size, raw material base and structure. It will do so by using first generation bioethanol processes and the interaction between an industrial and a municipal energy system as case studies, using the Sustainable Process Index as an LCA evaluation method.

Size and raw material

The first part of the contribution will explore different structural approaches for the production of bio-ethanol, from conventional central bio-ethanol plants with natural gas as an energy source to integrated, more de-central solutions based on various possibilities to provide process heat on the base of renewable resources. This analysis shows that with a change of the raw material base towards renewable resources a completely new discourse about size, location and technology choices will be opened. Besides the well known concept of ?economy of scale? the new concept of ?ecology of scale? will become increasingly important. The analysis shows, that an integrated, de-central process network based on renewable resources will reduce the ecological pressure of providing alternative fuels dramatically.

Integration of industry and societal needs

The second part of the contribution discusses new structural ways to integrate industrial production and societal demand for energy provision. Including societal needs (provision of heating for a city) and changing the raw material base to renewable resources again shows a very high potential for reducing the overall environmental burden while generating positive societal results (jobs as well as regional added value).

New industrial structures and requirements for LCA methods

The case studies show on the one hand that sustainability requires a profound re-structuring of industry as not only economic optimisation will shape industrial processes. The integration of environmental and social considerations into the decision making process will affect the raw material base, size and structure of the industry in the 21st century. As a rule process industry will be faced with the necessity to optimise not only single production lines but more complex, network-like structures, where de-central and central facilities will operate and provide services in terms of energy provision and regional value added besides the provision of goods.

LCA will play a prominent role in the optimisation of such integrated industrial systems. In order to support decisions in future, LCA evaluation methods have to fulfil certain requirements: they must be able to distinguish between different raw material and energy systems (especially to distinguish between fossil and renewable resources) and they must provide easy to read information for decision makers (preferably via aggregated measures). On top of that they must be able to evaluate networks of technologies rather than single technologies and provide clear indication about ecological ?hot spots? within technology networks as well as information about the effect of logistics and transport on the overall ecological pressure of industrial systems.

Key words: LCA, Sustainable Process Index (SPI), sustainable industrial systems, renewable resources