工业副产醋酸甲酯制醋酸正丙酯工艺设计与优化

Process design and optimization of industrial byproduct methyl acetate to n-propyl acetate

工业生产精对苯二甲酸的过程中会产生大量醋酸甲酯。为实现醋酸甲酯的有效利用,提出了一种利用酯交换和反应精馏技术的工艺,将醋酸甲酯和正丙醇转化为高附加值的醋酸正丙酯和甲醇,并进行了稳态建模计算。为降低产品分离过程的公用工程消耗,进一步采用变压精馏和热集成技术,对醋酸甲酯处理量为50 kmol/h的工艺进行了优化设计,并从技术(系统能耗和CO_(2)排放量)和经济(年均总成本)两方面对优化前后的工艺进行了比较。结果表明,优化前,工艺的系统能耗为7.85MW,CO_(2)排放量为1.33×10^(4)t/a,年均总成本为4.71×10^(6)CNY/a;优化后,工艺的系统能耗降至4.44MW,CO_(2)排放量降至0.75×104t/a,年均总成本降至3.29×10^(6) CNY/a。本研究可为醋酸甲酯的高效利用和醋酸正丙酯的工业生产提供参考。

In the industrial production of purified terephthalic acid,a significant amount of methyl acetate is generated as a byproduct.To efficiently utilize methyl acetate,a process utilizing transesterification and reactive distillation technologies has been proposed to convert methyl acetate and n-propanol into high-value n-propyl acetate and methanol,with rigorous steady-state modeling.To reduce utility consumptions during the separation process,pressure swing distillation and heat integration technologies were further employed to optimize the process with a feedstock of 50 kmol/h of methyl acetate.A comparative analysis of the process before and after optimization was conducted from both technical(systematic energy consumptions and CO_(2) emissions)and economic(total annual costs)perspectives.The results show that prior to optimization,the systematic energy consumptions of the process are 7.85 MW,CO_(2) emissions amount to 1.33×10^(4) t/a,and the total annual cost is 4.71×10^(6) CNY/a.However,following optimization,systematic energy consumptions decrease to 4.44 MW,CO_(2) emissions are reduced to 0.75×10^(4) t/a,and the total annual cost decrease to 3.29×10^(6) CNY/a.This study serves as a reference for the efficient utilization of methyl acetate and the industrial production of n-propyl acetate.