Method for reducing dilute nitric acid to nitrous acid

A technology of dilute nitric acid and nitrous acid, which is applied in the field of coal chemical industry, can solve the problems affecting the ability of blood to transmit oxygen, achieve the prospect of large-scale industrial application, reduce the requirements of equipment, and reduce the effect of separation steps

Active Publication Date: 2015-08-26
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Nitrite easily reacts with hemoglobin in the blood to form methemoglobin, which affects the blood's ability to transport oxygen

Method used

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  • Method for reducing dilute nitric acid to nitrous acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] The particle size is 20-30 mesh 5g CeO 2 The catalyst was loaded into a glass tube reactor with a diameter of 15mm, and was reduced at 400°C for 5h under a hydrogen atmosphere. Then switch to nitrogen atmosphere, add 1wt% dilute nitric acid reaction solution with a metering pump, the reaction temperature is 40°C, and the WHSV is 1.2h -1 , the reduction reaction was carried out under a nitrogen atmosphere at atmospheric pressure. The conversion rate of nitric acid is 90%, and the selectivity of nitrous acid is 95%.

Embodiment 2

[0019] The particle size is 5g ZrO of 20-30 mesh 2 The catalyst was loaded into a glass tube reactor with a diameter of 15mm, and was reduced at 450°C for 8h under a hydrogen atmosphere. Then switch to a nitrogen atmosphere, add 2wt% dilute nitric acid reaction solution with a metering pump, the reaction temperature is 60°C, and the WHSV is 1.5h -1 , the reduction reaction was carried out under a nitrogen atmosphere at atmospheric pressure. The conversion rate of nitric acid was 88%, and the selectivity of nitrous acid was 97%.

Embodiment 3

[0021] The particle size is 20-30 mesh 5g MoO 3 The catalyst was loaded into a glass tube reactor with a diameter of 15mm, and was reduced at 390°C for 4h under a hydrogen atmosphere. Then switch to nitrogen atmosphere, add 2wt% dilute nitric acid reaction solution with a metering pump, the reaction temperature is 100°C, and the WHSV is 2.0h -1 , the reduction reaction was carried out under a nitrogen atmosphere at atmospheric pressure. The conversion rate of nitric acid is 96%, and the selectivity of nitrous acid is 90%.

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Abstract

The invention relates to a method for reducing dilute nitric acid to nitrous acid; in a coal-to-ethylene glycol process, a large amount of dilute nitric acid waste liquid can be produced, is discharged after NaOH neutralization, and can pollute water resources. According to the method for reducing dilute nitric acid to nitrous acid, a reaction is continuously carried out in a fixed bed reactor under normal pressure; under the catalytic action, in an N2 atmosphere and at a temperature of 30-100 DEG C, dilute nitric acid is reduced to nitrous acid; and nitrous acid can be further participated in the coal-to-ethylene glycol process. The process not only can improve economic benefits, but also lowers pollution to the water resources.

Description

technical field [0001] The invention belongs to the field of coal chemical industry, and specifically reduces dilute nitric acid waste liquid produced in the process of coal chemical industry to nitrous acid, and the nitrous acid further participates in the reaction to reduce waste liquid discharge. Background technique [0002] Ethylene glycol is an important chemical raw material, mainly used as a raw material for solvents, antifreeze and synthetic polyester resins. At present, ethylene glycol is mainly prepared by direct hydration of ethylene oxide. Since the preparation of ethylene oxide is based on ethylene, mass production mainly depends on petroleum resources. However, my country's overall energy characteristics are rich in coal, gas, and low in oil. Therefore, it is of great significance to efficiently convert coal into chemical raw materials such as ethylene glycol and reduce the dependence of chemical raw materials on petroleum resources, which is conducive to opt...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B21/50
Inventor 马继平徐杰贾秀全陈晨李德财王敏石松
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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