The Novel Study Of Reactive Distillation For Synthesizing Ethylene Glycol Diacetate

Ethylene glycol diacetate(EGDA)is a commonly used chemical solvent,under the background that people increasingly attach importance to environmental protection,as a kind of environmental friendly green organic chemicals,ethylene glycol diacetate can be used as a substitute for many organic solvents used in industrial production.At present,most of the industry synthesis ethylene glycol diacetate by esterification method with ethylene glycol and acetic acid.It's a typical reversible,consecutive second-order esterification and the conversion of EG and yield of EGDA are limited by the reaction rate and chemical equilibrium.Owing to the absence of ethylene glycol and ethylene glycol monoacetate in the reaction mixture,it is difficult to abtain high purity ethylene glycol diacetate from the reaction mixture.In this work,not only RD technique,but also the reaction of ethylene oxide(EO)hydration is activated as an auxiliary reaction to intensify the EGDA production unit.It's a novel intensified reactive distillation process to produce high purity EGDA in one column with only 19 theoretical trays.EO hydration is a non-catalytic,rapid,irreversible and exothermic reaction.The water produced by the esterification reaction is removed and in situ used in the EO hydration reaction.That could break the equilibrium of the esterification reaction and promote the EG conversion.And this intensification can save a huge amount of energy that previously consumed for removing water.After that,the EG production in hydration reaction is right to be the reactant of the esterification reaction.That is to say,ethylene oxide hydration reaction as auxiliary,can not only reduce the concentration of the main reaction products,but also increase the concentration of the reactants.Double effect promote the esterification reaction to the positive direction.As a result,both the reaction rate and productivity will be improved in theory.The steady state simulation and dynamic simulation of the process were carried out by Aspen Plus and Aspen Dynamics simulation software.Impacts of four important parameters,i.e.,number of theoretical stage,feed position,reflux ratio,rate of distillation and operating pressure on the purity of EGDA,energy consumption,conversion,selectivity and yield were investigated to achieve an optimal processdesign in the steady state simulation by Aspen Plus,including energy saving optimization design based on steady state simulation.What,s more,the dynamic state simulation by Aspen Plus Dynamics has achieved an innovative process to produce EGDA without EG feed on the basis of steady state.Higher purity of ethylene glycol diacetate was gained with less energy consumption.