Method for processing nitrous oxides in chlorinated exhaust of nitroaromatic compounds

A technology for nitro compounds and aromatic compounds, applied in the fields of energy saving, emission reduction and environmental protection, can solve the problems of high storage risk, low product added value, and difficulty in obtaining solid ammonia salts, etc., and achieve the effect of improving economic benefits.

Active Publication Date: 2009-08-12
JIANGSU YANGNONG CHEM GROUP +1
View PDF0 Cites 18 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The above two commonly used methods: the first method will produce a large amount of high-concentration saline wastewater, which cannot be discharged directly, but the gas will be changed into liquid, which will also pollute the environment; the second method can solve the outlet of tail gas, but its products It is an aqueous solution of ammonium chloride, ammonium nitrate and ammonium nitrite. Because ammonium nitrite is easily decomposed under high temperature and high concentration conditions, it is difficult to obtain solid ammonia salt, so there are problems such as low product added value and high storage risk.

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
  • Method for processing nitrous oxides in chlorinated exhaust of nitroaromatic compounds
  • Method for processing nitrous oxides in chlorinated exhaust of nitroaromatic compounds
  • Method for processing nitrous oxides in chlorinated exhaust of nitroaromatic compounds

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] The tail gas produced by the chlorination reaction is introduced into the tail gas absorption tower from the top of the chlorination reaction tower. The tail gas is composed of about 26% nitrogen dioxide, 18% nitroxyl chloride and 56% nitrosyl chloride, and 70% is added dropwise to the top of the tail gas absorption tower. Sulfuric acid, the temperature is controlled at about 30°C, the efficiency of absorbing nitrogen oxides is 65%, the content of nitric acid in the absorbed mixed acid is 10%, and the content of nitrous acid is 2%. The tail gas that cannot be completely absorbed is absorbed with water and dilute alkali in sequence to ensure that no harmful gas escapes.

Embodiment 2

[0032] The tail gas produced by the chlorination reaction is introduced into the tail gas absorption tower from the top of the chlorination reaction tower, and the tail gas is composed of about 26% nitrogen dioxide, 18% nitrosyl chloride and 56% nitrosyl chloride, and 80% is added dropwise from the top of the tail gas absorption tower. % sulfuric acid, the temperature is controlled at about 30°C, the efficiency of absorbing nitrogen oxides is 80%, the content of nitric acid in the absorbed mixed acid is 6%, and the content of nitrous acid is 5%. The tail gas that cannot be completely absorbed is absorbed with water and dilute alkali in sequence to ensure that no harmful gas escapes.

Embodiment 3

[0034] The tail gas produced by the chlorination reaction is introduced into the tail gas absorption tower from the top of the chlorination reaction tower, and the tail gas is composed of about 26% nitrogen dioxide, 18% nitrosyl chloride and 56% nitrosyl chloride, and 90% is added dropwise from the top of the tail gas absorption tower. % sulfuric acid, the temperature is controlled at about 30°C, the efficiency of absorbing nitrogen oxides is 90%, the content of nitric acid in the absorbed mixed acid is 6%, and the content of nitrous acid is 12%. The tail gas that cannot be completely absorbed is absorbed with water and dilute alkali in sequence to ensure that no harmful gas escapes.

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 provides a comprehensive utilization method of aromatic nitro compound chlorination tail gas, which is characterized in that: sulfuric acid is used for absorbing nitrogen oxides and nitryl chloride in the aromatic nitro compound chlorination tail gas to generate mixed acid containing nitric acid, sulfuric acid and nitrous acid, the generated mixed acid is used for nitration of aromatic compound; the tail gas which is not completely absorbed by sulfuric acid is absorbed by water to form acid liquor comprising hydrochloric acid mainly and a little nitric acid; the remaining tail gas is processed by dilute base to be absorbed completely, and waste liquor enters wastewater treatment system.

Description

technical field [0001] The invention relates to a process for comprehensive utilization of acid gases such as nitrogen oxides and nitroxyl chloride in the chlorination tail gas of aromatic nitro compounds, and belongs to the technical field of environmental protection, energy saving and emission reduction. Background technique [0002] Aromatic nitro compounds undergo chlorination reaction with chlorine gas at high temperature, and the nitrogen oxides contained in the tail gas produced are one of the main pollutants in the atmosphere, and the acid gas produced by the decomposition of nitroxyl chloride with water also pollutes the environment more seriously. According to data reports, the treatment methods of nitrogen oxides and nitroxyl chloride tail gas produced by the chlorination of aromatic nitro compounds are mainly: discharge after absorption by lye or limestone; use as nitrogen fertilizer after absorption with ammonia water. [0003] The above two commonly used method...

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 & Authority Applications(China)
IPC IPC(8): B01D53/56B01D53/78
Inventor 丁克鸿顾志强顾克军许金来吴惠顾咸建蒋智慧殷恒志徐立辉
Owner JIANGSU YANGNONG CHEM GROUP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap