Steady state and dynamic simulation of complex chemical processes : Process design

Based on the general framework of either an equation oriented approach or the modular methods, simulation strategies related to different problems involving complex chemical processes have been developed. These strategies include features that provide default initial estimates for simultaneous simulation and optimization with the steady state modular approach and consistent initialization for solving the differential-algebraic (or only algebraic) equations by the equation oriented approach. Accurate simulation of a process is made possible through the prediction of correct physical properties. The simulation strategies, therefore ensure robust and efficient simulation of complex chemical processes even though non-linear and computationally expensive thermodynamic models are used. Numerical examples covering such complex processes as the high pressure, high temperature methanol synthesis process, the highly interactive aromatic extraction process and a heterogeneous azeotropic separation process are presented. Also, the different features of the two simulators used, SEPSIM and DYNSIM, are highlighted through simulation of several single unit and multiple unit processes