甲苯法生产己内酰胺废液的处理和综合利用研究

对甲苯法生产己内酰胺的废液进行处理及综合利用,探讨了废液的分离工艺条件、盐的提纯与精制及油的分析与利用。结果表明,通过共沸蒸馏和溶剂萃取洗涤,己内酰胺废液分离成水、粗盐和油,最佳共沸蒸馏条件为:m(甲苯)∶m(苯)∶m(废液)=1∶1∶2,共沸温度82℃,洗涤剂为甲醇,得其m(水)∶m(油)∶m(粗盐)=30∶44∶26。水可并入公司现有处理排放系统;粗盐经液相色谱分析,其主要成分为环己烷羧酸磺酸,采用双氧水氧化-活性炭吸附进行提纯精制,较佳的精制条件为:m(活性炭)∶m(双氧水)∶m(粗盐)=0.50∶0.75∶15,65℃氧化10 min,活性炭吸附30 min,w(环己烷羧酸磺酸)=98.5%,收率达90.2%,可外销或进行深加工利用;对油建立了反相离子对色谱法,鉴定了其成分并测定了各成分的质量分数:w(己内酰胺)=6.36%,w(环己烷羧酸)=4.53%,w(环己羧酸磺酸)=0.25%,可进行回收利用;同时测定了油的主要技术指标:燃烧热为20 384 J/g,28℃时运动黏度为225 mm2/s,w(硫)=1.07%,闪点为108.5℃,w(水)=0.8%,w(灰分)=0.08%和w(机械杂质)=0.09%,达到了炉用燃料油(重油)的技术指标。己内酰胺废液的分离工艺已在石家庄化纤有限责任公司进行了小试。

Studies on Treatment and Comprehensive Utilization of Waste Fluid in the Production of Caprolactam from Toluene

In order to study the caprolactam waste fluid treatment and the comprehensive utilization of Shijiazhuang Chemical Fiber Company,the waste fluid separation process conditions,refining and purifying of the salt as well as the analysis and utilization of the oil were discussed. The results showed that the waste fluid was segregated into three parts with m(water):m(salt):m(oil)=30:44:26 by the azeotropic distillation and solvent extraction washing.The best azeotropic distillation condition is found:m(toluene):m(benzene):m(waste fluid)=1:1:2,azeotropic temperature is 82 ℃,extraction detergent is methanol.The water can be treated with the company′s existing drainage system.The main component of the crude salt is cyclohexane carboxylic acid-sulfonic acid detected by liquid chromatography.The purification of the salt is achieved by using hydrogen peroxide and activated carbon.The optimum condition is found:m(activated carbon):m(hydrogen peroxide):m(the beginning of salt)=0.50:0.75:15,oxidation temperature 65 ℃,oxidation time 10 min and adsorption time 30 min.The w(cyclohexane carboxylic acid-sulfonic acid) was 98.5% and the yield reached 90.2%.The salt can be exported or for further application.The main components of the oil and their relative contents were identified and determined by the reversed-phase ion-pair chromatography:w(caprolactam)=6.36%,w(cyclohexane-carboxylic acid)=4.53%,w(cyclohexyl carboxylic acid sulfonic acid)=0.25%.All of them can be recycled.The main technical indicators of the oil were determined.The results showed that the heat of combustion was 20 384 J/g,the kinematical viscosity was 225 mm~2/s at 28 ℃,w(S) was 1.07%,flash point was 108.5 ℃,w(water)=0.8%,w(ash)=0.08% and w(mechanical impurities)=0.09%,in accord with the technical indicators of a furnace fuel oil (heavy oil).Caprolactam waste filed separation process had been proved successful in Shijiazhuang Chemical Fiber Company in a bentch-scale test.