Study Of Oxime Hydrolysis Reaction- Separation Coupled Process

Hydroxylamine is a widely-used chemical raw material, which is applied in biochemistry, fine chemicals, medicine and so on. Because hydroxylamine is unstable, hydroxylamine salt is in place of hydroxylamine in industry and transport. Hydroxylamine hydrochloride is the most common and most used hydroxylamine salt. There are many routes in the production of HA, However the routes have shortcomings, which are complicated, costly, troublesome, low product yield and other issues. It is necessary to develop a new production process of hydroxylamine hydrochlorideOxime hydrolysis is a feasible route of synthesis of hydroxylamine hydrochloride. This reaction is a thermodynamically limited reaction, which has a lower equilibrium conversion of the reaction. And the reaction temperature has little effect on the reaction equilibrium conversion. Oxime hydrolysis has not been applied. In this work, Oxime hydrolysis-distillation process is proposed for the production of hydroxylamine hydrochloride to solve the problem of Oxime hydrolysis reaction.The reaction starting material was investigated. Butanone oxime and hydrochloric acid are the most appropriate the starting material for oxime hydrolysis-distillation process. The influence of hydrolysis reaction conditions is studied. Thermodynamic equilibrium conversion of butanone oxime hydrolysis reaction is only about 14%. The reaction temperature is less impact on the thermodynamic equilibrium. It is necessary to use reaction-distillation technology to remove reaction by-product butanone, to promote the equilibrium of the reaction, to improve the conversion.The reaction-distillation process optimum conditions are studied. the optimum concentration of hydrochloric acid was 0.5mol/L, with the reaction-distillation temperature of 120?, with oxime acid ratio of 1.2: 1. The conversion of reaction-distillation process can reach about 94%. The conversion of oxime hydrolysis reaction is also improved by reaction-vacuum distillation process. With temperature 80? and degree of vacuum reaction 80 KPa, the conversion of the reaction-vacuum distillation process can reach about 93%.The factors of reaction-distillation process were investigated. There are three equilibrium factors affecting the reaction-distillation process. The reaction equilibrium constant is 15. Increasing the concentration of hydroxylamine hydrochloride promotes the reaction-distillation process. The temperature of reaction affects reaction-separation process, because it reduces hydroxylamine hydrochloride solubility.