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Method for treating waste gas in ethyl nitrite production process

A technology of ethyl nitrite and treatment method, which is applied in the field of waste gas treatment in the process of ethyl nitrite generation, can solve the problems of inability to achieve absorption effect, low proportion of ethyl nitrite, harsh reaction conditions, etc., and achieve good economic benefits and social benefits, environmental protection, mild reaction conditions

Active Publication Date: 2016-11-16
CHEM TECH ACAD OF SHANDONG PROVINCE
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Uncondensed ethyl nitrite is usually recovered partly by secondary condensation, but it is usually difficult to recover completely due to the low proportion of ethyl nitrite in the waste gas
The inventor found through experiments that no matter whether liquid caustic or weakly acidic urea solution is used for uncondensed ethyl nitrite, it cannot achieve a good absorption effect, and the absorption rate is generally below 50%.
[0007] The application number is 201210575718.4 and the title of the invention is: a method for removing nitrite in CO coupling oxalate tail gas, which discloses the use of copper as a catalyst at a reaction temperature of 200 ° C and a reaction pressure of 0.3 MPa to remove nitrite. In addition to the reaction of ethyl nitrite, the reaction conditions are harsh and the cost input is large

Method used

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  • Method for treating waste gas in ethyl nitrite production process
  • Method for treating waste gas in ethyl nitrite production process
  • Method for treating waste gas in ethyl nitrite production process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Mix 51g (0.51mol) 98% concentrated sulfuric acid and pure water into a 50% sulfuric acid solution. The obtained sulfuric acid solution is dropped into 69.7g (1.0mol) 99% sodium nitrite aqueous solution under stirring, and the reaction temperature is controlled at 25-40℃ , About two hours after dropping sulfuric acid. Pass the generated gas through the air supply bottle connected to the air pump, which is the air supply oxidation device. The red-brown gas after the air supply is passed into a two-stage absorption bottle with an absorption liquid temperature of 40℃. The composition of the two-stage absorption liquid is 300g ( 5mol) urea+588.7g (1.5mol) 31% hydrochloric acid+5g ammonium nitrate+606.3g water is a 20% urea acid solution. All waste gas was collected and analyzed by spectrophotometry with naphthalene ethylene diamine hydrochloride, and the conversion rate of nitrogen oxides reached 99.7%.

Embodiment 2

[0039] Add 75g (1mol) ethyl nitrite into 150g of 80% ethanol aqueous solution, heat it in a water bath at 35°C for 1 hour, increase the temperature of the water bath to 50°C and heat it for another hour, and pass the produced ethyl nitrite gas directly into the absorption liquid without condensation. It is a two-stage absorption bottle at 40℃. The composition of the two-stage absorption liquid is 300g (5mol) urea + 588.7g (1.5mol) 31% hydrochloric acid + 5g ammonium nitrate + 606.3g water to form a 20% urea acidic solution. Absorbed by absolute ethanol at 5°C. After the reaction, gas chromatography was used to detect the absolute ethanol that absorbed the exhaust gas, and the conversion rate of ethyl nitrite was 99.3%.

Embodiment 3

[0041] Mix 51g (0.51mol) 98% concentrated sulfuric acid and pure water into a 50% sulfuric acid solution, and the resulting sulfuric acid solution is dripped with 69.7g (1.0mol) 99% sodium nitrite + 46.9g 99% ethanol (1.01mol) + 150g while stirring In the mixed solution composed of pure water, the reaction temperature is controlled at 25-40°C, and the sulfuric acid is dropped in about two hours. The gas produced is first collected by the refrigerant at -5°C to collect most of the ethyl nitrite, and then the uncondensed gas is passed through the gas cylinder connected to the air pump. The reddish-brown gas after the gas supply is passed into the two-stage absorption bottle. The composition of the grade absorption liquid is a 20% urea acidic solution made up of 300g (5mol) urea+588.7g (1.5mol) 31% hydrochloric acid+5g ammonium nitrate+606.3g water. The exhaust gas was first absorbed by absolute ethanol at -5°C, and all that could not be absorbed was collected and analyzed by the ...

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Abstract

The invention discloses a method for treating waste gas in ethyl nitrite production process, belonging to the technical field of environmental protection. The method comprises the following steps: introducing gas flow containing ethyl nitrite and nitric oxides into absorption liquid containing urea, hydrogen ions and nitrate for reacting. According to the method disclosed by the invention, the cost of treating the produced waste gas mixed with nitric oxides and ethyl nitrite during ethyl nitrite protection is low, the reaction is mild, the concentration of the ethyl nitrite in tail gas can be greatly reduced, the environment can be effectively protected, and the method has excellent economic benefits and social benefits.

Description

Technical field [0001] The invention belongs to the technical field of environmental protection, and is specifically a method for treating waste gas during the generation of ethyl nitrite. Background technique [0002] Ethyl nitrite is a commonly used chemical product, often used in the synthesis of sodium azide and diethyl oxalate. The main method for producing ethyl nitrite is ethanol-sodium nitrite-sulfuric acid method. This method has high yield and low equipment requirements, but the nitrous acid produced in the reaction cannot be completely converted, and a large amount of nitrogen oxides will be produced by-products. At the same time, the produced ethyl nitrite is difficult to be completely collected because of its low boiling point. . [0003] Nitrogen oxide refers to a compound composed of only two elements: nitrogen and oxygen. Common nitrogen oxides are nitric oxide (NO, colorless), nitrogen dioxide (NO 2 , Reddish brown), nitrous oxide (N 2 O), dinitrogen pentoxide (...

Claims

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Application Information

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IPC IPC(8): B01D53/78B01D53/86B01D53/76B01D53/56
CPCY02C20/10B01D53/78B01D53/76B01D53/8625B01D2251/2067
Inventor 岳涛邢文国杨旭冯维春陈琦魏凤邢伶王达彤纪晓红
Owner CHEM TECH ACAD OF SHANDONG PROVINCE
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