Design of a Process Plant for Dimethyl Ether Synthesis from Syngas Using Direct Method

Abstract

The search for alternative renewable and less polluting energy sources has gained prominence thus, there is an increasing interest in the use of Dimethyl Ether (DME) as a clean alternative fuel and raw material in the chemical industry. The simulation of a plant for the production of Dimethyl Ether from Syngas using direct synthesis method has been carried out in this work. The simulation was done using ASPEN HYSYS software. In this research, equations were developed for the reactor by adopting the principle of conversation of mass. The developed equations were simulated using computer software called MATLAB in order to solve the developed reactor model. The change in reaction rate and mole fraction across the reactor length in the process as regards the yield of products and depletion of reactants are discussed. The variation of reactor volume, space time, space velocity, heat load and pressure drop with fractional conversion are discussed. The results of the variation of mole fraction of the reactants and products in the reactor from HYSYS and MATLAB simulation softwares were compared. The product composition for the Mixer, Compressor, Reactor, Stripper, Distillation Column and Separator were analyzed and it showed that the yield of DME, which is our product of interest, increased across the mixer, compressor, reactor, stripper, distillation column and separator with percentage values of 28.67%, 44.69%, 83.61% and 93.79% respectively. DME had a final yield of 93.79%. The results of the variation of mole fraction of the reactants and products in the reactor from HYSYS and MATLAB simulation softwares were compared and they were observed to follow the same trend of decrease in mole fractions of the reacting species and increase in mole fraction of product along the length of the reactor