醋酸加氢制乙醇精馏模拟与优化

Process simulation and optimization of hydrogenation of acetic acid to ethanol

对醋酸加氢制乙醇液相产物的分离过程进行模拟优化,通过Aspen Plus流程模拟软件,采用修正的NRTL模型,在醋酸加氢制乙醇体系全流程模拟的基础上,分别考察了回流比、塔板数、进料位置等对脱酸塔(T1)、脱轻塔(T2)、脱水塔(T3)的分离过程的影响。对于20万t/a的工业乙醇生产装置三塔操作参数优化结果为:脱酸塔T1塔板数43、进料位置30、回流比(物质的量比)0.64;脱轻塔T2塔板数40、进料位置14、回流比11.8;脱水塔T3塔板数45、进料位置42、回流比2.9。通过优化出最佳分离操作参数,可使塔釜能耗降低39%。同时得出各塔板上温度分布、气液相浓度分布模拟结果。为进一步的工业放大提供坚实基础。

Base on the process simulation of hydrogenation of acetic acid to ethanol and the modified NRTL model,the effects of the operating parameters,including the stage number of distillation column,the number of feed stage and reflux ratio,on the separation process were investigated by using Aspen Plus software.The result shows that when ethanol annual outputis 0.2 million tons,the optimum operating parameters are as follows：the stage number of distillation column T1 is 43,the feed stage is No.30,reflux ratio（molar ratio） is 0.64;the stage number of distillation column T2 is 40,the feed stage is No.14,the reflux ratio is 11.8;and the stage number of distillation column T3 is 45,the feed stage is No.42,the reflux ratio is 2.9.Under the optimized separation parameters,the reboiler duty can reduced by 39%.The simulation results of temperature and gas-liquid concentration distribution on each column plate can be achieved.It has great significance for further industrialization.