Process for continuously producing trimethyl phosphite by using N, N-dimethylaniline

Abstract

The invention relates to a process for continuously producing trimethyl phosphite by using N, N-dimethylaniline, belonging to the technical field of trimethyl phosphite preparation. Through steps such as synthesis, water washing, layering, drying, distillation and wastewater reclamation, wastewater treatment expenses are low, the quality and the production capacity of trimethyl phosphite products are guaranteed, and the wastewater can be produced into a widely used ammonium chloride fertilizer through concentration and crystallization. The defects that the energy consumption is higher, the alkali charge is great, the production cost is higher, the produced wastewater contains a large quantity of sodium chloride and the sodium chloride obtained after concentration cannot be used when triethylamine is used for continuously producing trimethyl phosphite are overcome; and the problems that a batch process is only suitable for small-scale enterprise production, the output is smaller, the yield is low and the environmental pollution is great are also solved. Besides, products and solvent in water washing liquid are separated through a centrifugal separator, ammonium chloride is effectively removed through second alkali washing, and the problem that the ammonium chloride blocks distillation equipment is well solved.

Description

technical field [0001] The invention relates to a process for continuously producing trimethyl phosphite by an N,N-dimethylaniline method, belonging to the technical field of trimethyl phosphite preparation. Background technique [0002] At present, there are two main methods for preparing trimethyl phosphite in China: [0003] 1. Use N,N-dimethylaniline as the acid-binding agent to prepare trimethyl phosphite, all of which are batch methods. The process is to first mix the solvent, the acid-binding agent N,N-dimethylaniline, and methanol once Put it into the reaction kettle, while adding phosphorus trichloride dropwise, feed ammonia, the pH value is 5-6 to keep the reaction; The part of trimethyl ester and solvent is put into the salt dryer, and the solvent containing trimethyl phosphite after salt drying is referred to as crude ester, and then the crude ester is put into the distillation tower for separation, and the product trimethyl phosphite is obtained. The separated...

AI Technical Summary

Problems solved by technology

[0019] The object of the present invention is to provide a kind of under the same condition as triethylamine continuous production trimethyl phosphite, can overcome the energy consumption that exists when triethylamine continuous production trimethyl phosphite is higher, use alkali Large quantity and high production cost; it can also solve the shortcomings that the batch method is only suitable for small-scale production, the output is small, the yield is low, and the environmental pollution is large; and the product quality of trimethyl phosphite can be guaranteed The process of continuous production of trimethyl phosphite by N,N-dimethylaniline method and production capacity

Images