绿色化学原则下国内外乙腈生产工艺分析  

Analysis of the acetonitrile production technology under principles of green chemistry

作　　者：陈阳 白鹏[1] 郭翔海[1] CHEN Yang;BAI Peng;GUO Xianghai(School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学化工学院

出　　处：《化工进展》2019年第10期4374-4388,共15页Chemical Industry and Engineering Progress

摘　　要：从绿色化学角度对乙腈合成、提纯、废物处理、成本控制等方面进行了分析。主要介绍了以乙醇为原料直接合成乙腈的方法,包括氢化氨化法和氨氧化法;分析了合成方法中催化剂的性能,对比了各类催化剂对应的乙醇转化率和对乙腈的选择性;介绍了萃取精馏和变压精馏的提纯工艺,分析了变压精馏的优势、废物处理的方法以及成本控制的策略。提出了符合绿色化学要求的乙腈生产工艺组合:生物乙醇来源广泛且工艺逐渐成熟,适合作为合成原料;合成工艺宜采用氨氧化法,以分子氧为氧化剂,负载钒或钯的活性氧化锆作为催化剂,乙醇转化率接近99%,乙腈的选择性达到95%~99%。变压精馏作为提纯工艺比萃取精馏更加符合绿色化学要求,达到产品纯度99.9%的同时避免了溶剂的使用,有利于进行工艺放大。分析了副产物处理工艺的有效性和经济性,严格控制全流程的碳排放,为乙腈工厂升级转型提供了新思路。The synthetic methods,purification,waste treatment and cost control of acetonitrile synthesis processes were analyzed according to the principles of green chemistry.The methods of directly synthesis of acetonitrile from ethanol,including hydrogenated ammonization and ammoxidation,were mainly introduced.The performance of the catalysts was analyzed and compared in terms of the conversion of ethanol and selectivity to acetonitrile.Two purification processes of extractive distillation and pressureswing distillation,were discussed,and the advantages of pressure swing distillation,waste treatment methods and cost control strategies were illustrated.An acetonitrile production process was proposed based on the requirements of green chemistry.Bioethanol is a renewable and rich available source and its production technology is mature,making it an ideal synthetic substrate.The synthesis process would be better to adopt the ammonia oxidation method,with molecular oxygen as oxidant,and supported vanadium or palladium on activated zirconia as a catalyst.The ethanol conversion is close to 99%,and the selectivity of acetonitrile is 95%—99%.As for the purification process,the pressure-swing distillation was more advantageous with respect to the green chemical requirements than the extractive distillation.And the product purity could reach 99.9%without the use of additional solvent,which were beneficial to the process scale-up.The by-product treatment processes were evaluated by their effectiveness and economy.Besides,the carbon emission of the whole process is strictly controlled,which provides a new idea for the upgrading and transformation of acetonitrile factory.

关 键 词：乙腈 制备 绿色化学 氨氧化 催化剂 纯化 过程系统 

分 类 号：TQ226.6[化学工程—有机化工]