ω-腈基十一酸分离提纯工艺优化

Optimization of the Processes of Separating and Purifying ω-Cyanoundecanoic Acid

以ω-腈基十一酸(11-CUA)的收率(或质量百分含量)及纯度为目标函数,采用液相色谱法与电位滴定法进行相应的分析检测,对自行设计的两种不同的分离提纯11-CUA的萃取与结晶工艺进行对比实验,确定了合理的分离提纯工艺,然后用单因素实验法对所选的合理工艺的部分单元操作进行工艺参数优化.优化工艺参数为:氨气氨化时溶液pH值8.0-10.0、温度25-35℃、搅拌速率120-240rpm,萃取溶剂为甲苯,酸化试剂用硫酸(或盐酸)、酸化剂试用量:H2SO4;HN3为0.6(摩尔分数)、溶液pH值1.5-2.0、温度55-60℃,采用环己烷作为结晶介质,结晶溶液溶质初始质量比为5.00g粗品11-CUA/100.00g环己烷,粗品11-CUA溶解温度50-55℃,粗品11-CUA溶解后结晶前的静置沉降时间20min、结晶温度10℃,结晶母液可以直接重复利用一次.

ω - cyanoundecanoic acid(11 - CUA), which obtained from pyrolyzing 1,1- peroxydicyclohexylamine(FXA), can be separated and purified by extraction and crystallization treament. Comparative experiments of two different processes were carried out on the basis of taking the recovery yield and pureness of 11 - CUA and other indexes as the objective functions of these processes. The reasonable process were thereby defined.The reasonable process was as follow: ammonifying the solution of pyrolyzing PXA containing 11- CUA with ammonia gas or ammonia aqueous solution, washing impurities away by extraction, acidifying the solution of ammonium of 11- CUA to give crude free 11 - CUA, crystallizing crude 11 - CUA to yield pure 11 - CUA.The single factor experiments of some unit operations of the reasonable process were carried out to optimize the operation parameters of unit operations. Some important operation parameters were listed:pH value of the solution being ammonified was 8.0- 10.0,temperature 25- 35℃, stirring rate 120-240rpm,extraction solvent was toluene, reagent for acidifying ammonium of 11 -CUA was sulfuric acid or hydrochoric acid, and pH value of the solution being acidified 1.5-2.0, H2SO4 : NH3 was 1.2: 2.0(mol/ mol) , temperature 55 - 60℃, crystallixation solvent was cyclohexane, initil ratio of mass of crude 11 - CUA and cyclohexane 5. 00g/ 100.00g, dissolving temperature of crude 11 - CUA in crystallize was 20 minuted, crystallization temperature 10℃, reuse times of crystallization mother liquor was one times.