Simulation And Optimization Of The Process Of Producing DME By Gasified Methanol

With the increasing demand of oil resources, oil price is increasingly climbing. Given the relatively rich coal energy structure in our country, taking coal to replace oil as raw material to produce chemical products has become a hot research in recent years. Among the research hot, the program of coal preparation of Dimethyl ether (DME) is a research project with development prospects.The process of producing DME by gasified methanol was investigated. In this paper, the optimization and simulation of preparation process of Dimethyl ether through gasified methanol was studied based on large process simulation system Aspen Plus.This paper mainly was reviewed characteristics and uses of Dimethyl ether, Dimethyl ether was briefly introduced in internal and external current situation of the development of industrialization of China. Dimethyl ether synthesis process route and catalyst were introduced, including sulfuric acid method, syngas synthesis method, CO2hydrogenation method and gas phase methanol method.Optimization and simulation of preparation process of Dimethyl ether through gasified methanol was studied based on large process simulation system Aspen Plus. Simulation of the process parameters and product specifications meet with the technological requirements of the plant. The simulated annual output was100400t, which closed to the actual value of100000t, dimethyl ether mass fraction of the product is99%, methanol mass fraction is0.7%, the water mass fraction is0.2%,Dimethyl ether rectified column which was mainly contained separate-absorb and rectify-separate cell was simulated and optimized, the result of simulation and optimization was that theoretical plate of CH3OH gasification column was equal to21, importing position was equal to6, amount of distillation was equal to23350kg/h, and reflux ratio was equal to1.5. Besides, washing column theoretical plate number was10, DME distillation column theoretical plate number was10, importing position was5, and amount of distillation was12700kg/h, and reflux ratio was0.4. After optimization, the reboiler energy consumption of dimethyl ether rectifying column was reduced by28%.Dimethyl ether distillation process was improved, the process parameters were simulated and optimized, the result of simulation and optimization was that amount of distillation of high pressure distillation column was equal to300kg/h, dimethyl ether mass fraction and product was maximum; reflux ratio was0.9, reboiler and condenser heat load of high pressure distillation column was minimum. DME distillation column theoretical plate number was10, importing position was5, and amount of distillation was12650kg/h, and reflux ratio was0.1. Compared with the previous processes, reboiler heat load is lower30%, condenser heat load is lower33%the improved distillation process is better.