Method for recycling phosphorous acid from dimethyl ester rectification residual liquid

A technology of phosphorous acid and dimethyl ester, which is applied in the direction of phosphorous acid, phosphorus oxyacids, chemical instruments and methods, etc., can solve the problems of environmental pollution, limited growth benefits, etc., reduce production costs, increase recovery rate, and reduce three wastes The effect of emissions

Inactive Publication Date: 2017-01-18
ANHUI DONGZHI GUANGXIN AGROCHEMICAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

A certain amount of liquid phosphorous acid (dimethyl ester raffinate) is produced during the distillation process, which is now sold directly, with limited growth benefits and certain environmental pollution

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] A method for recovering phosphorous acid from the rectification raffinate of dimethyl phosphite, which mainly includes the following steps: (1) heating the rectification raffinate of dimethyl phosphite to 50°C, and then adding activated carbon to the raffinate Carry out decolorization treatment, keep the temperature until the decolorization is complete; (2) filter the solution after decolorization in step 1 while it is hot, collect the filtrate, and transfer it to the reactor; (3) add dropwise to the reactor of step 2 For hydrochloric acid, the dropping rate is controlled at 100mL per second, the acidolysis temperature is controlled at 70°C, and the vacuum degree is controlled at -0.1MPa. When the vacuum degree drops, the amount of acid to be dropped is reduced and fully stirred until the acidolysis is complete; (4) After acidolysis When there is no obvious gas discharge, the acid dripping should be stopped. After the acid dripping stops, there is still gas discharge, an...

Embodiment 2

[0019] A method for recovering phosphorous acid from the rectification raffinate of dimethyl phosphite, which mainly includes the following steps: (1) heating the rectification raffinate of dimethyl phosphite to 60°C, and then adding activated carbon to the raffinate Carry out decolorization treatment, keep the temperature until the decolorization is complete; (2) filter the solution after decolorization in step 1 while it is hot, collect the filtrate, and transfer it to the reactor; (3) add dropwise to the reactor of step 2 For hydrochloric acid, the dropping rate is controlled at 100mL per second, the acidolysis temperature is controlled at 50°C, and the vacuum degree is controlled at -0.1MPa. When the vacuum degree drops, the amount of acid to be dropped is reduced and fully stirred until the acidolysis is complete; (4) After acidolysis When there is no obvious gas discharge, the acid dripping should be stopped. After the acid dripping stops, there is still gas discharge, an...

Embodiment 3

[0022] A method for recovering phosphorous acid from the rectification raffinate of dimethyl phosphite, which mainly includes the following steps: (1) heating the rectification raffinate of dimethyl phosphite to 60°C, and then adding activated carbon to the raffinate Carry out decolorization treatment, keep the temperature until the decolorization is complete; (2) filter the solution after decolorization in step 1 while it is hot, collect the filtrate, and transfer it to the reactor; (3) add dropwise to the reactor of step 2 For hydrochloric acid, the dropping rate is controlled at 100mL per second, the acidolysis temperature is controlled at 30°C, and the vacuum degree is controlled at -0.1MPa. When the vacuum degree drops, the amount of acid to be dropped is reduced and fully stirred until the acidolysis is complete; (4) After acidolysis When there is no obvious gas discharge, the acid dripping should be stopped. After the acid dripping stops, there is still gas discharge, an...

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PUM

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Abstract

The invention provides a method for recycling phosphorous acid from a dimethyl ester rectification residual liquid, wherein the method mainly includes the following steps: (1) heating the dimethyl phosphite rectification residual liquid, and decoloring with active carbon; (2) filtering the solution after decoloring in the step 1 while being hot, and collecting the filtrate; (3) dropping hydrochloric acid, controlling the dropping speed, the acidolysis temperature and the vacuum degree, and stirring fully until acidolysis is completed; (4) when no obvious gas is discharged after acid dropping, stopping acid dropping, after the acid dropping is stopped, if gas is still discharged, requiring to appropriately supplement hydrochloric acid, and allowing tail gas generated in the acidolysis process to be merged into a chloromethane recycling header pipeline; and (5) obtaining an aqueous solution having chloromethane gas removed, namely liquid phosphorous acid, concentrating and crystallizing the aqueous solution, and purifying to obtain solid phosphorous acid with the content of more than or equal to 98% or directly taking as an aqueous solution for use. The method achieves clean production, reduces three-waste emissions, improves the by-product recovery rate, and reduces the production cost.

Description

technical field [0001] The invention belongs to the field of fine chemical production, and in particular relates to a method for recovering phosphorous acid from dimethyl ester rectification raffinate. Background technique [0002] The raffinate, also known as phosphorous acid, is a cyan viscous liquid with a strong pungent odor. The boiling point is 200°C and the relative density is 1.651. It is easily soluble in water and alcohol. The CAS number is 13598-36-2. It decomposes into phosphine and orthophosphoric acid at high temperature, which is highly toxic and explosive. [0003] Phosphorous acid is mainly used as a reducing agent, a nylon brightener, and also as a raw material for phosphite, a pesticide intermediate, and a raw material for organic phosphorus water treatment chemicals. In recent years, the market demand for phosphorous acid products in my country has shown an increasing trend year by year. The development of related application technologies has played a po...

Claims

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Application Information

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IPC IPC(8): C01B25/163C02F9/04C02F103/36C02F101/10
CPCC01B25/163C01P2006/80C02F1/001C02F1/283C02F1/66C02F9/00C02F2101/105C02F2103/36
Inventor 刘云飞金斐王先武钱潮涌
Owner ANHUI DONGZHI GUANGXIN AGROCHEMICAL CO LTD
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