Denitration method of nitration waste acid

A nitrification waste acid and denitrification technology, applied in the field of denitrification, can solve the problems of incomplete tail gas treatment, yellow smoke, high investment cost and high operation cost, and achieve the effects of less three waste discharge, low operation cost and high denitrification rate

Inactive Publication Date: 2018-05-15
JIANGSU FENGSHAN GROUP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The investment cost and operating cost of both are very high, and yellow smoke will be produced if the exhaust gas treatment is not thorough

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Add 30g of sulfuric acid with a concentration of 50% into a 500mL four-neck flask, start stirring, and slowly add 20g of urea. After the addition is complete, stir for 30min to obtain a urea sulfate solution. Add 240g of waste acid with an acidity of 86.4%. The fraction is 2.4%, the mass fraction of nitrous acid is 3.2%, and slowly added dropwise to the above urea sulfuric acid solution (the total molar ratio of urea sulfate to nitric acid and nitrous acid is 1.3:1), no yellow smoke is emitted during the dropping process, control the dripping Adding temperature is 40-100°C, keep warm at 80-90°C for 1h after the dropwise addition, wait until there is no obvious gas release in the reaction bottle, cool down to room temperature, detect the mass fraction of nitric acid in the denitrification waste acid is 0.06%, and the content of nitrous acid is 0 , The denitrification rate is 98.9%.

Embodiment 2

[0025] Add 30g of sulfuric acid with a concentration of 85% to a 500mL four-neck flask, start stirring, and slowly add 20g of urea. After the addition is complete, stir for 30min to obtain a sulfuric acid urea solution. Add 100g of waste acid with an acidity of 80%. Among them, the mass of nitric acid The fraction is 5%, and the mass fraction of nitrous acid is 6.5%. Slowly add it dropwise into the urea sulfuric acid solution (the total molar ratio of urea sulfate to nitric acid and nitrous acid is 1.5:1). No yellow smoke is released during the dropping process, and the dropping is controlled. The temperature is 40-100°C. After the dropwise addition, the temperature is lowered to room temperature, and the concentration of nitrate and nitrite ions is detected. The mass fraction of nitric acid in the denitrated waste acid is 0.08%, the content of nitrous acid is 0, and the denitrification rate is 99.3%.

Embodiment 3

[0027] In a 500mL four-necked flask, add 30g of sulfuric acid with a concentration of 98%, start stirring, slowly add 40g of 50% aqueous urea solution dropwise, after the addition is complete, stir for 30min to obtain a urea sulfuric acid solution, use 300g of waste acid with 60% acidity, Among them, the mass fraction of nitric acid is 1%, the mass fraction of nitrous acid is 1%, and slowly added dropwise to the urea sulfuric acid solution (the total molar ratio of urea sulfate to nitric acid and nitrous acid is 3:1), and no yellow smoke is released during the dropping process , the temperature is 60-90°C, after the dropwise addition, when there is no obvious gas release in the reaction bottle, cool down to room temperature, the mass fraction of nitric acid in the waste acid after denitrification is 0.03%, the content of nitrous acid is 0, and the denitrification rate is 98.5%.

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Abstract

The invention discloses a denitration method of nitration waste acid. The denitration method comprises the following steps: dropwise adding waste acid containing nitric acid and nitrous acid into a urea sulfate solution, wherein no yellow smoke is emitted during dropwise addition and the reaction temperature is 40-100 DEG C; after the dropwise addition, when no gas is emitted, cooling to room temperature, and detecting the nitrate content and the nitrite content of the waste acid, wherein the mass fractions of nitric acid and nitrous acid in the waste acid after denitration are lower than 0.1%and the denitration rate is 98% or above. By the denitration method, the nitric acid and the nitrous acid in the waste acid after a nitration reaction are reduced into clean nitrogen, carbon dioxideand water; the treatment condition is mild; the denitration rate is high; the denitration method has the advantages of low three-waste emission, low operating cost, high denitration rate, environmentfriendliness and the like, and can be applied to industrial production.

Description

technical field [0001] The invention belongs to the field of denitrification, and in particular relates to a denitrification method for nitration waste acid. Background technique [0002] Nitration reaction is an organic unit reaction that is often encountered. At present, the most commonly used nitrating agent in industrial nitration reaction is the mixed acid of nitric acid and sulfuric acid. In order to improve the reaction yield, the nitric acid in the mixed acid is usually excessive. The waste acid contains a small amount of nitric acid and nitrous acid, and the nitric acid and nitrous acid in the waste acid will be decomposed into NO when it meets water or high temperature 2 and NO and other toxic and harmful gases, and produce a large amount of yellow smoke, resulting in the difficulty and high cost of waste acid treatment. [0003] NO 2 The mixed gas with NO is also called nitrous gas, NO 2 It mainly damages the human respiratory tract. Long-term exposure can caus...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F1/58C02F101/16C02F103/34
CPCC02F1/58C02F2101/16C02F2103/34
Inventor 王晋阳瞿保华宋媛媛孙旭峰李俊卿单永祥
Owner JIANGSU FENGSHAN GROUP
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