A kind of preparation method of high-purity tributyl phosphate

Abstract

The invention discloses a method for preparing high-purity tributyl phosphate. The method includes steps of enabling butanol and phosphorus oxychloride to react with each other to generate mixtures, carrying out tower washing on the mixtures, layering the mixtures after the mixtures stand still, acquiring 25-28% of hydrochloric acid solution from water phase, neutralizing organic phase by the aid of gaseous ammonia until a pH (potential of hydrogen) value of the organic phase reaches 7, allowing the mixtures to stand still, separating the water phase from the organic phase, crystallizing the water phase, separating solid from liquid to obtain ammonium chloride solid, recycling mother liquid, adding water into the organic phase to wash the organic phase, keeping the pH of 6-7 under the control, coarsely removing alcohol from coarse ester layers under the pressures of 7-15kPa at the temperatures of 80-110 DEG C after the water phase is separated from the organic phase, recycling the most butanol; adding water into the coarse ester layers to be used as entrainers, and carrying out reduced pressure distillation under the conditions of pressures of 7-15kPa and temperatures of 80-110 DEG C; recycling the butanol in distilled mixtures of the butanol and the water; obtaining the high-purity tributyl phosphate from column reactors. A mass ratio of the water added into the coarse ester layers to distillates is 0.5-1.5:1. The method for preparing the high-purity tributyl phosphate has the advantages that consumption of a large quantity of alkali, degradation of the tributyl phosphate and generation of chloride waste liquid can be prevented, conditions of high required pressures and high temperature can be omitted, and energy consumption and the cost can be reduced; the tributyl phosphate obtained by the aid of the method is high in purity, the purity of the tributyl phosphate can reach 99.9% at least, and export-grade requirements can be met.

Description

technical field [0001] The invention relates to a purification method, in particular to a preparation method of high-purity tributyl phosphate. Background technique [0002] Tributyl phosphate is referred to as TBP, and its molecular formula is (C 4 h 9 O) 3 PO, a colorless liquid with a pungent odor, is an important chemical product with a wide range of uses. It can be used as industrial defoamer, plasticizer, metal extractant, solvent extractant, etc. It also has an important use in purifying phosphoric acid. [0003] At present, the industrial production of TBP generally uses butanol and phosphorus oxychloride as raw materials, and reacts at room temperature to obtain tributyl phosphate. The chemical reaction equation is as follows: POCl 3 +3C 4 h 9 OH→(C 4 h 9 O) 3 PO+3HCl [0004] The methods currently used for the purification of tributyl phosphate are: 1. acid-binding method, adding sodium formate (or sodium acetate, sodium butoxide) in advance to remove t...

AI Technical Summary

Problems solved by technology

This method needs to consume a large amount of alkali, and the neutralization process will also cause the degradation of tributyl phosphate due to the local excessive concentration of alkali, release a large amount of heat, increase energy consumption, and the potassium chloride and sodium chloride solutions produced cannot be recycled. , causing environmental pollution

The conditions of vacuum distillation are harsh, the energy consumption is high, the requirements for equipment are high, and the production cost is high, resulting in low technical and economic value of the process

At present, the yield of tributyl phosphate is lower than 85%, and the purity is not high

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