The Research On Low Pollution Production Of CLT Acid

In this thesis, a method of producing CLT acid with less pollution is introduced.In order to minimize the pollution of the environment with waste acids and waste acidic salt solution, following measures were taken: (1) Instead of using excess sulfuric acid, - sulfonation reaction was carried out in the presence of excess toluene and the water produced during the sulfonation was removed by azeotropic distillation. After sulfonation the excess toluene was removed by distillation and small amount of sulfuric acid was added; (2) After chlorination and nitration using traditional method, contrary to the traditional method of salt out or acid out process, the product of nitration was directly neutralized with sodium carbonate; (3) After removing most of byproduct and sodium bisulfate,85～90%of waste acidic salt solution was recycled. The producing rate of CLT acid we gained from the method is more than 60%,which is calculated by toluene sulfonic acid, and its production content is more than 98%.