Absorption-hydration Hybrid Method For The Sparation Of Light Hydrocarbon Mixtures:Process Simulation And Optimization

An absorption-hydration hybrid method for the separation of ethylene from dry gas is proposed.Water in oil emulsion is utilized,in which oil provides absorption and water for the hydration.However,currently there is no available property pack for multiphase equilibrium calculation that includes hydrate in any of the commercial softwares.In order to simulate and evaluation the performance of proposed absorptionhydration process,in this thesis parameters for ethylene formation in water in oil emulsion are regressed.Subsequently,the kinetic models as well as equilibrium models are built as moduals via Aspen Custom Modeler.The moduals are then exported to Aspen Plus as blocks,which can be used as unit operations in Aspen Plus flowsheeting.Afterwards,simulation of the whole process is carried out in Aspen Plus.Meanwhile,economic evaluations are also incorpated into the simualtions.By comparing the proposed process with conventional absorption process,it is found the hybrid process can reduce cost by about 12%.It is also found in the simulation that the structure of hydrate has a great influence on its separation ability,especially for multistage designs.Finally,the challenges as well as the key technologies of large scale flow chart simulation is analyzed.A parallel global optimization framework for the simulation of large flowcharts is proposed,which includes parallel implemented global optimization algorithm,simplified models,the method to help the convergence of complex models and heat integration evaluation tools.The proposed framework is especially useful for large scale heat integrated flow charts.