Ethyl chloride production desulfurization method

A technology of ethyl chloride and ethyl thiophosphoryl, which is applied in the field of preparation of low-toxic pesticide intermediates, can solve problems such as incompleteness, difficulty in industrial realization, and difficulty in wastewater treatment, and achieve the effect of eliminating sewage

Inactive Publication Date: 2016-05-11
WUHAN UNIV OF TECH +1
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The main problems of this process route are: 1) about 450 kilograms of liquid caustic soda water analysis is required for each ton of product, and the amount of wastewater produced is about 1200 kilograms. The wastewater contains a large amount of sodium sulfide, salt, and by-products, and wastewater treatment is difficult; 2) sulfur treatment produces A large amount of exhaust gas, the exhaust gas contains a certain amount of hydrogen sulfide, mercaptan, sulfide
[0005] In the chlorination product body, the sulfur is dissolved in the ethyl chloride liquid, and the promise is not separated, and the subsequent process cannot be processed
Sulfur will gradually precipitate out by cooling down and standing still, but this process needs at least 72 hours, and it is not thorough, so it is difficult to realize industrially

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Ethyl chloride production desulfurization method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] In a 1000ml three-neck flask equipped with a stirrer and a reflux tube, add 640g of the chlorinated product obtained after chlorination, raise the temperature to 85°C, add 5.4g of sodium thiosulfate, stir and cool down to below 50°C, stir for 1 hour, and put into the filter to filter the precipitated sulfur. The filtrate ethyl chloride crude product I was returned to the flask, heated to 70°C, added 3.1g of sodium metabisulfite, stirred and cooled down to below 25°C, stirred for 30 minutes, put into a filter to filter the secondary precipitated sulfur, and the filtrate was ethyl chloride The crude compound II was put into a distillation flask, and distilled under 60Pa vacuum at 95°C to obtain 465g of ethyl chloride. According to GC analysis, the purity was 99.3%.

Embodiment 2

[0030] In a 1000ml three-neck flask equipped with a stirrer and a reflux tube, add 640g of the chlorinated product obtained after chlorination, raise the temperature to 70°C, add 5.5g of sodium bisulfite, stir and cool down to below 50°C, stir for 1 hour, put into the filter to filter the precipitated sulfur. The filtrate ethyl chloride crude product I returns to the flask, heats up to 55°C, adds 2.6g of sodium dithionite, stirs and lowers the temperature to below 25°C, stirs for 30 minutes, puts it into a filter to filter the secondary precipitated sulfur, and the filtrate is ethyl The crude chloride II was put into a distillation flask, and distilled under 60Pa vacuum at 95°C to obtain 467g of ethyl chloride. According to GC analysis, the purity was 99.26%.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a method for desulfurizing in ethyl chloride production. The method comprises the following steps: (1), carrying out primary crystallization: in an ethyl chloride chlorination process, heating after chlorination is completed, adding a crystallization aid B, cooling to lower than 50 DEG C under stirring, placing into a filter tank for filtering sulfur, wherein filtrate is an ethyl chloride crude product I; (2), carrying out secondary crystallization: heating the ethyl chloride crude product I, adding a crystallization acid C, cooling to lower than 25 DEG C under stirring, placing into the filter tank for filtering sulfur, wherein the filtrate is an ethyl chloride crude product II; and (3), refining: distilling the ethyl chloride crude product II under reduced pressure to obtain a product with purity over 99%. The method disclosed by the invention has beneficial effects that the method realizes hydrolysis-free chlorination production of ethyl chloride, eliminates production and emission of sewage in the chlorination link, poisonous and harmful gases such as hydrogen sulfide, and the like, and can obtain ethyl chloride crude product II with purity over 96%; and the ethyl chloride crude product II enters a distillation kettle, a finished product with content over 99% is obtained by distilling through a decompression film, and kettle residue is lower than 10%.

Description

technical field [0001] The invention relates to a preparation method of a low-toxic pesticide intermediate, in particular to a method for desulfurization in the ethyl chloride chlorination process. Background technique [0002] Ethyl chloride is one of the basic raw materials for organic synthesis and an important intermediate for the production of pesticides and medicines. In terms of pesticides, it can be used to synthesize organophosphorus insecticides phoxim, chlorpyrifos, triazophos, diazinon, profenofos, etc. It has a wide range of uses. [0003] The currently commonly used process route in China is to use phosphorus pentasulfide as raw material, add ethanol to vulcanize, and generate ethyl sulfide (O, O-diethyl phosphorodithioate) and hydrogen sulfide, hydrogen sulfide is absorbed with lye, ethyl sulfide The product is made into ethyl chloride and then the process of chlorination and hydrolysis is adopted. The specific process is as follows: chlorine gas is introduce...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & AuthorityPatents(China)
IPC IPC(8): C07F9/20C01B17/027
Inventor桂厚瑛王新洪雍道新周秋名王成城李忠良易玲芳彭辉
OwnerWUHAN UNIV OF TECH