对甲苯磺酸的制备与应用

摘要

本文主要对对甲苯磺酸的制备工艺和应用前景进行了研究，分别采用了传统工艺和两种改进工艺制备对甲苯磺酸，并对此进行了比较。改进工艺克服了传统工艺的弊端。第一种改进方案是运用了部分结晶选择性原理制备对甲苯磺酸。甲苯与浓硫酸在甲苯沸腾回流(110℃)的条件下反应5h后，在80℃下加一定量的水使对甲苯磺酸结晶水合物从磺化混合液中析出，而间位和邻位两种异构物留在体系中，补充原料后继续反应，体系重新达到化学平衡状态，再析出产品。如此循环反应-结晶过程，即抑制了新的间位和邻位异构物进一步产生，又使较纯的对位产物分离出体系。优化了工艺条件，结果表明，该生产工艺路线为硫酸定量反应，无废酸或甲苯排放，产品纯度大于85%，对于高选择性生产对甲苯磺酸和清洁磺化过程具有重要的意义。第二种改进工艺是将甲苯缓慢滴加到热的浓硫酸中，此工艺减短了实验时间，使操作时间为平时的四分之一，不但节省了反应物的用量，而且还大大提高了产量，改进的方法制备收率高，反应操作简单。

本文以对甲苯磺酸做催化剂催化合成了邻苯二甲酸二丁酯，其产率为84.0%，用浓硫酸作催化剂的产率为82.8%，尽管两者间的产率相近，但对甲苯磺酸没有腐蚀性，且在反应过程中不能产生废酸，对环境无污染。

关键词:对甲苯磺酸;磺化;结晶;催化剂

Abstract

This paper focuses on the p-toluene sulfonic acid preparation process and application prospects were studied, respectively using traditional technology and two kinds of improved preparation process of p-toluene sulfonic acid, and make a comparison. Improved technology overcomes the defects of the traditional process. The first improvement plan is the use of partially crystalline selective preparation principle of p-toluene sulfonic acid. Refluxing toluene with concentrated sulfuric acid in toluene (110 ℃) 5h reaction conditions, adding a certain quantity of water at 80 ℃for crystalline hydrate precipitated from the sulfonated toluene sulfonic acid in the mixture, and meta - and ortho two isomers in the system, supplementary materials after reaction, system to achieve chemical equilibrium, then precipitation products. So the cycle reaction crystallization process, which inhibits the new meta - and ortho isomer to produce, and the para product is pure isolated system. Process conditions, the optimization results show that, the production process for sulfuric acid quantitative reaction, no waste acid or toluene emissions, the purity of product is more than 85%, high selectivity for the production has the vital significance to the toluene sulfonic acid and clean the sulfonation process. Process improvement of second is concentrated sulfuric acid to toluene is slowly added into hot, this process to shorten the experimental period, the operation time is usually 1/4, not only to save the amount of reactants, but also greatly improve the yield, high yield improved method of operation is simple, reacti

The catalyst p-toluene sulfonic acid dibutyl phthalate was synthesized, its yield is 84%, with concentrated sulfuric acid as catalyst. The yield is 82.8%, although similar between the yield, but no corrosive p-toluene sulfonic acid, and can not waste acid produced in the reaction process, no pollution to the environment.

Keywords: catalyst p-toluene sulfonic acid sulfonation crystallization