Experimental Study Of Preparation Of Hydroxylamine Sulfate By Hydrolysis Of Ketone Oxime

As an important chemical product,hydroxylamine sulfate is widely used in pharmaceutical,pesticide and other research and industrial production.The traditional production process of hydroxylamine sulfate has many problems,such as:complex process,low yield,high cost,large waste discharge and high energy consumption.Based on the successful industrialization application of hydroxylamine hydrochloride by A-O-H process(combined process of ammonia oxime-oxime hydrolysis),our group proposed the preparation of hydroxylamine sulfate by A-O-H process,which has good atomic economy and good prospects for industrial applications.This paper selects the Butanone oxime/Butanone system,and studies the preparation of hydroxylamine sulfate by hydrolysis of ketone oxime in A-O-H process,the main contents are as follows:The reaction equilibrium conversion rate of butanone oxime hydrolysis is only 12-15%.In order to improve the yield of hydroxylamine sulfate,the reaction of butanone oxime to the positive reaction direction was promoted by using reactive-distillation coupling to strengthen the removal of the by-product butanone.Under the low concentration reaction system(sulfuric acid concentration<40 wt%),the yield of hydroxylamine sulfate increased by 80%relative to the equilibrium conversion rate.To further reduce the energy consumption of distillation,the preparation of hydroxylamine sulfate under high concentration reaction system is realized.Based on the solubility data of hydroxylamine sulfate,through the theoretical analysis of the high concentration reaction conditions,the concentration range of sulfuric acid was selected for 45 wt%-60 wt%,and the hydrolysis reaction of butanone oxime was strengthened by coupling reaction-distillation and reaction-crystallization,and the yield of hydroxylamine sulfate reached 91%-93%.Under the high concentration reaction system,the bulk precipitation of hydroxylamine sulfate crystals with reaction,which has an effect on the safety of the process.By analysing the influential factors of liquid mass transfer and heat conduction in high concentration reaction system,two or more reactive-distillation units were proposed in tandem operation,and the crystallization of a crystallization kettle was added to the two reaction-distillation unit.The improved process not only improved the safety of process,but also the yield of hydroxylamine sulfate reaches 96%-99%.The effect of the acid oxime ratio and reactant concentration on the hydrolysis process of butanone Oxime was investigated experimentally,the optimum reaction conditions for preparation of hydroxylamine sulfate from the hydrolysis process of butanone oxime is "Acid ratio oxime is>0.5:1,sulfuric acid concentration 60 wt%".