Design and analysis on new process for synthesis of ethyl methyl carbonate by reactive extractive distillation.

A new process for the synthesis of ethyl methyl carbonate through reactive extractive distillation was proposed to address the difficulties in separating azeotropic mixtures and the excessive formation of byproduct (diethyl carbonate) in the production of ethyl methyl carbonate via reactive distillation. Using Aspen Plus software, the effect of the extractant (diethyl carbonate) on the vapor-liquid equilibrium of the system was first investigated. Then the reactive extractive distillation column was simulated to study the effects of the number of theoretical plates in the reaction section, the number of theoretical plates in the extraction section, the feeding position, entrainer ratio, and reflux ratio on the reactive extractive distillation process. Under the optimized process parameters, the molar fraction of dimethyl carbonate at the top of the reactive extractive distillation column was reduced to 0.49%, and the single conversion of dimethyl carbonate, selectivity of ethyl methyl carbonate, and ethyl methyl carbonate yield reached 83.5%, 99.9% and 83.4% respectively. Finally, a process for the reactive extractive distillation was designed with the objective function of total annual cost, achieving process parameters that meet the production requirements. It was found by comparison that the reactive extractive distillation process exhibits better economic performance than conventional reactive distillation processes when the added value of 1 t of ethyl methyl carbonate is 145.50 CNY higher than that of diethyl carbonate. [ABSTRACT FROM AUTHOR]