Process Study Of Transesterification Assisted Separation Of Coal-based Ethylene Glycol With Co-production Of 1,2-Butene Carbonate

Five-membered cyclic carbonates are very important organic chemical raw materials and intermediates with a wide range of applications,such as organic synthesis,battery electrolyte,supercritical fluid separation technology,cosmetic additives and other fields.1,2-butene carbonate(BC)is an important five-membered cyclic carbonate with high commerical value.But there is a shortage of raw materials1,2-butanediol(1,2-BDO)for BC production by transesterification.While 1,2-BDO is the byproduct in coal-to-ethylene glycol(EG)route,which brings the puzzle in separation.Therefore,this article innovatively proposes integrated processes to achieve the separation of EG and 1,2-BDO while continuously producing 1,2-BC.The whole process of transesterification distillation was established,and the design parameters and operating conditions of each tower were obtained through sensitivity analysis.First,the kinetics data was measured in an autoclave in the presence of KIP321 catalyst.Effects of stirring speed,catalyst loading,initial molar ratio of reactants and temperature on the conversion of glycols were investigated.Based on reasonable assumptions,a pseudo-homogeneous reaction kinetic model was established,kinetic constants were regressed and kinetic equations were obtained.Then,a reactive distillation column model was proposed,in which transesterfication occurred from mixed glycols and and dimethyl carbonate to cyclic carbonates and methanol.Sensitivity analysis resulted in better design parameters and operating conditions.Finally,two complete technological processes of reactive distillation were designed,and the analysis and comparison of the two processes were carried out.The work done in this paper can provide basic data and design guidance for industrial applications.