己内酰胺生产中产品消光值调优措施浅析

Analysis of optimization measures for extinction value of product during caprolactam production

根据己内酰胺生产装置实际情况,采用单因素法讨论了环己酮肟贝克曼重排反应条件、粗己内酰胺萃取条件、己内酰胺-苯溶液水洗条件等对己内酰胺产品消光值的影响,并提出了消光值的调优控制措施。结果表明:当一级重排温度为100℃、二级重排温度为125℃时,己内酰胺产品消光值最低,为0.013;当重排反应发烟硫酸中游离三氧化硫(SO3)质量分数为18%时,己内酰胺产品消光值最低,为0.013;萃取塔的萃取温度为40℃时,萃取塔所得到的己内酰胺-苯溶液的消光值最低,为0.402;当萃取塔残液界面为75%时,己内酰胺-苯溶液的消光值最低,为0.435;当己内酰胺-苯溶液中己内酰胺质量分数为19.5%时,己内酰胺-苯溶液的消光值最低,为0.386;己内酰胺-苯溶液的一级和二级水洗流量分别为600kg/h和400kg/h时,己内酰胺产品的消光值可降低至0.012。

In view of the actual production situation of caprolactam refining unit,the effects of Beckmann rearrangement reaction conditions of cyclohexanone oxime,extraction conditions of crude caprolactam-benzene solution and washing conditions of caprolactam-benzene solution on the extinction value of caprolactam were discussed.And the control measures for optimizing extinction value of caprolactam were put forward.The results showed that caprolactam had the minimum extinction value of 0.013 when the first rearrangement temperature was 100℃and the second rearrangement temperature was 125℃or when the mass fraction of free sulfur trioxide(SO 3)in fuming sulfuric acid of rearrangement reaction was 18%;the caprolactam-benzene solution obtained by the extraction column showed the minimum extinction value of 0.402 at an extraction temperature of 40℃and exhibited the minimum extinction value of 0.435 when the residual liquid interface was 75%in extraction column;and the caprolactam-benzene solution showed the minimum extinction value of 0.386 when the mass fraction of caprolactam was 19.5%in caprolactam-benzene solution;and caprolactam exhibited the minimum extinction value of 0.012 when the first and second washing flow were 600 kg/h and 400 kg/h,respectively,for caprolactam-benzene solution.