in the field of non-energy use of fossil fuels, energy and material flows are very complex. We developed a process chain model to understand the interlinkages and the resulting CO2 emissions of such a system. This work aims to assess the implications of structural changes in production processes together with recycling strategies and production rates. The model is based on data for West Germany in 1989. Starting from an Excel spreadsheet model for mass flows we began to transfer our model to a conventional process simulator in order to test the optimizing capabilities and the balance options for material and energy flows. Due to the complexity of the task, we tested the usefulness of the simulator for the envisioned purposes using a small example for the production of PVC. The first results of a sensitivity study and an optimization run for recycling strategies are presented, Finally, the advantages and disadvantages of using a process simulator for the modelling of process chains is discussed.