The simulation of industrial ecosystems

The ISO 14000 norm provides a framework in which a continuous improvement of the environmental performance of a process may be realised. Life Cycle Assessment (LCA) forms an integral part of ISO 14000 however, its inventory analysis presently often simplifies process routes for metals processing to simple averaging black-boxes that represent whole processes. This approach hardly makes it possible to capture the detail of complex interconnected materials processing systems as found in metals processing. As a consequence the use of LCA in its present form as a tool to invoke improvement for metal processing and recycling systems may be questionable. As an alternative to the poor inventory analysis of LCA for the above mentioned systems, this paper discusses the architecture of a simulation model that permits the detailed simulation of interconnected material cycles in view of realising the ISO 14000 norm and other imposed environmental legislation. This means that interconnected routes such as for Cu, Sn, Zn, Pb, Al, Mg and Mn are simulated simultaneously. This would put the very useful LCA methodology for these applications on a more sound basis, rendering the subsequent improvement analysis better for these systems. The proposed architecture is characterised by four levels, each of the levels providing information to different interested parties, i.e. from decision-makers, politicians to plant managers and metallurgists. Very much like thermodynamic simulators, which communicate with appropriate thermodynamic data in a suitable standard database, a possible environmental database is defined, which can efficiently communicate with the different levels defined by the simulator. This architecture clarifies the complexity of these systems. Various illustrative case studies and corresponding numerical results provide an overview of the proposed architecture as well as the scope of this approach. Without providing a statement regarding the overall environmental soundness of the interconnected Al, Cu, Sn, Zn, Mn, Mg and Pb production routes, the results give an indication what detail results can be produced for these process routes spanning countries and continents. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.