Prozeßentwicklung: Von der Exergieanalyse bis zur EDV‐gestützten Optimierung

Process development: From exergy analysis to computer‐aided optimisation. In processes in which chemical compositions or states are altered, limiting case analyses based on the first and second laws of thermodynamics are often of use during preliminary process analyses. Since the introduction of computers for process calculations exergy analyses can be carried out in a simple way and weak points in initial designs in the sense of the second law conveniently located. It is also possible to use exergy analyses to make product predictions if transferable practical exergy losses are available from past experience. In low temperature and energy technology the use of suitably defined efficiencies have been of use for many years in eliminating less attractive processing routes and thus reducing the number of possible designs to be investigated. For many decades so‐called „Sum Q/T Diagrams” have been used in low temperature processing to visualize and improve temperature profiles in heat exchanger networks. Recently technology has been further developed into „Pinch Technology”. At the end of process development comes the final detailed optimization. The expensive and time consuming sequential way of working used in the past is being gradually replaced today with equation‐oriented simulation and optimization tools such as the O PTISIM program. Expert systems, in principal, offer the chance of supporting the chemical engineer during the initial design of complete and complex processes. However, the experience with such systems to date has shown that a practical solution lies a long way into the future.