用于甲醇与乙腈体系分离的变压间歇精馏模拟优化  

Simulation and optimization of pressure-swing batch distillation for separating the methanol-acetonitrile system

作　　者：郭昊乾 李雪飞 李小亮 GUO Haoqian;LI Xuefei;LI Xiaoliang(Beijing Research Institute of Coal Chemistry,China Coal Research Institute Corporation Ltd.,Beijing 100013,China;Beijing Key Laboratory of Coal Based Energy Conservation and Environmental Protection Carbon Materials,Beijing 100013,China;State Key Laboratory of Coal Mining and Clean Utilization,Beijing 100013,China)

机构地区：[1]煤炭科学技术研究院有限公司煤化工分院,北京100013 [2]煤基节能环保炭材料北京市重点试验室,北京100013 [3]煤炭资源开采与洁净利用国家重点试验室,北京100013

出　　处：《煤质技术》2020年第2期21-26,33,共7页Coal Quality Technology

基　　金：国家重点研发计划资助项目(2018YFB0605604);国家科技重大专项资助项目(2016ZX05045-005)。

摘　　要：为了有效降低排放废水的COD及原料成本,采用变压间歇精馏工艺以分离由甲醇和乙腈形成的最低共沸物。针对甲醇和乙腈共沸物,基于Txy相图以分析分离该共沸物系的可行性,并借助Aspen Plus和Aspen Dynamics模拟软件对工艺流程进行构建,即以年度总费用最低为目标,优化工艺的进料组成、液体分率、操作压力等参数。结果表明,当进料组成中甲醇含量为85 mol%、液体分率为0.5、低高压塔操作压力分别为1 atm和3 atm时,年度总费用(268514美元)最低。基于以上参数,分离后的甲醇-乙腈共沸物系中各组分的纯度均高于99.9 mol%;甲醇产品罐中,甲醇纯度最终达到99.96 mol%,持液量为80.15 kmol;乙腈产品罐中,乙腈纯度最终达到99.999 mol%,持液量达到15.6 kmol。In order to effectively reduce the COD and raw material cost of discharged wastewater,a pressure swing batch distillation process to separate the lowest azeotrope formed from methanol and acetonitrile was adopted.For methanol and acetonitrile azeotrope,the feasibility for separation of azeotrope was analyzed based on the Txy phase diagram and the simulation flow sheet was established by using the Aspen Plus and Aspen Dynamics simulation software.To minimize total annual cost,the feed composition,liquid division ratio,and operating pressure were optimized.Results show that when the methanol feed composition is 85 mol%,the liquid division ratio is 0.5,the operating pressure of the two columns is 1 atm and 3 atm respectively,the total annual cost($268514)is the lowest.Based on the above parameters,the purity of each component in the separated methanol-acetonitrile azeotrope is higher than 99.9 mol%;in the methanol product tank,the purity of methanol finally reaches 99.96 mol%and the liquid holding capacity is 80.15 kmol;in the acetonitrile product tank,the purity of acetonitrile reaches 99.999 mol%and the liquid holding capacity reaches 15.6 kmol.

关 键 词：变压间歇精馏 共沸物 体系分离 模拟优化 年度总费用 进料组成 液体分率 操作压力 

分 类 号：TQ028.3[化学工程]