对甲苯磺酰氯生产中副产物的清洁利用研究

Study on Cleaning Utilization of By-products of p-Toluenesulfonyl Chloride Production

对甲苯磺酸是一种重要的化工中间体。本文主要研究对甲苯磺酰氯生产中副产物废硫酸为磺化剂制备对甲苯磺酸的清洁工艺。考察了甲苯和浓硫酸的投料比、反应温度、反应时间、结晶的析出温度等因素对精制后产品纯收率的影响。通过单因素法确定最佳的合成工艺。最佳的工艺条件为:甲苯:浓硫酸(98%)为3:1(摩尔比)、反应温度为120℃、反应时间为4 h、结晶的析出温度为50℃。在最佳工艺条件下,产品的收率在62%左右,纯度为98%以上。

P-toluenesulfonic acid is an important chemical industry intermediate.Waste sulphuric acid produced in preparation of p-toluenesulfonyl chloride,which was used as sulfonating agent,sulfonated toluene to produce high pure p-toluenesulfonic acid and the technology of preparing p-toluenesulfonic acid was studied.The effect of the weight ratio of toluene and concentrated sulfuric acid,reaction temperature,reaction time,crystallization temperature on the purity and yield of the product were investigated.The optimum conditions of synthesizing technology were determined,toluene： concentrated sulfuric acid=3：1,reaction temperature 120 ℃,reaction time 4 h,crystallization temperature 50 ℃.Under the optimum conditions,the yield of the product was about 62% and the purity can exceed 98%.