Process and gas-film air tower for treating hydrazine contained sewage generated in production of azodimethylamide

Abstract

A process for treating the hydrazine-contained sewage generated during production of azodimethylamide features use of a gas-film air tower, and includes such steps as deposition, introducing supernatant to a pre-treater, adding calcium carbide dregs or lime, blowing-oxidizing in the gas-film tower, defoaming tail gas, cyclone separation, heat exchange, adsorbing by sulfuric acid in an absorption tower, exhausting tail gas, press-filtering of oxidizing liquid from the said gas-film tower, biochemical homogenizing, mixing with city sewage, anaenbic biochemical treating, depositing, and aerobic biochemical treating. Its advantages are no environmental pollution, and low cost.

Description

technical field

[0001] The invention relates to a method for treating hydrazine-containing wastewater produced in the production of azodicarbonamide and a gas film stripping oxidation tower. Background technique

[0002] Azodicarbonamide (AC) foaming agent and modified compound products are foaming aids used for foaming various plastic and rubber products such as PVC, PE, ABS, and SBS. Because it is non-toxic, odorless, and pollution-free, it can be used for all kinds of soft and hard plastics, so it has become the most important foaming agent for plastic and rubber products today. The production of azodicarbonamide foaming agent in my country began in the 1960s. So far, there are more than 30 manufacturers, covering Jiangsu, Shanghai, Zhejiang, Fujian, Guangzhou and Yunnan. In 2000, the national production of azodicarbonamide was about About 60,000 tons, it is the country with the largest output in the world, accounting for about a quarter of the w...

Examples

Embodiment 1

[0041] The treatment method of hydrazine-containing wastewater produced by the production of azodicarbonamide: the hydrazine-containing wastewater of azodicarbonamide is sent to the preprocessor through the sedimentation supernatant, and the calcium carbide slag is added, and the pH is adjusted to 10. The slurry is sent to the air film stripping Oxidation tower, under the conditions of temperature 50°C, gas-liquid ratio 300, pressure 0.01MPa, residence time 0.5 hours, carry out deoxidation, blow off the tail gas at the top of the tower, go through defoaming, cyclone separation, heat exchanger and then enter the absorption tower, use 50% of sulfuric acid is absorbed, non-condensable tail gas is discharged, the oxidizing liquid is discharged from the stripping tower into the filter press for pressure filtration, the filtrate enters the biochemical homogeneous pool, and the pretreated effluent is adjusted to pH6 with acid or alkali in the biochemical homogeneous pool, and Mix it w...

Embodiment 2

[0043] The treatment method for the hydrazine-containing wastewater produced by the production of azodicarbonamide is as follows: the hydrazine-containing wastewater of azodicarbonamide is sent to the preprocessor through the precipitation supernatant, and lime is added to adjust the pH to 14. The tower, under the conditions of temperature 98°C, gas-liquid ratio 900, pressure 0.2MPa, and residence time of 3 hours, blows off oxidation, and the tail gas blown off at the top of the tower enters the absorption tower after defoaming, cyclone separation, and heat exchanger, and uses 80 % sulfuric acid is absorbed, non-condensable tail gas is discharged, the oxidizing liquid is discharged from the stripping tower into the filter press for pressure filtration, the filtrate enters the biochemical homogeneous pool, and the pretreated effluent is adjusted to pH9 with acid or alkali in the biochemical homogeneous pool, and mixed with Mix other industrial biochemical wastewater or urban sew...

technical field

[0001] The invention relates to a method for treating hydrazine-containing wastewater produced in the production of azodicarbonamide and a gas film stripping oxidation tower. Background technique

[0002] Azodicarbonamide (AC) foaming agent and modified compound products are foaming aids used for foaming various plastic and rubber products such as PVC, PE, ABS, and SBS. Because it is non-toxic, odorless, and pollution-free, it can be used for all kinds of soft and hard plastics, so it has become the most important foaming agent for plastic and rubber products today. The production of azodicarbonamide foaming agent in my country began in the 1960s. So far, there are more than 30 manufacturers, covering Jiangsu, Shanghai, Zhejiang, Fujian, Guangzhou and Yunnan. In 2000, the national production of azodicarbonamide was about About 60,000 tons, it is the country with the largest output in the world, accounting for about a quarter of the w...

Examples

Embodiment 1

[0041] The treatment method of hydrazine-containing wastewater produced by the production of azodicarbonamide: the hydrazine-containing wastewater of azodicarbonamide is sent to the preprocessor through the sedimentation supernatant, and the calcium carbide slag is added, and the pH is adjusted to 10. The slurry is sent to the air film stripping Oxidation tower, under the conditions of temperature 50°C, gas-liquid ratio 300, pressure 0.01MPa, residence time 0.5 hours, carry out deoxidation, blow off the tail gas at the top of the tower, go through defoaming, cyclone separation, heat exchanger and then enter the absorption tower, use 50% of sulfuric acid is absorbed, non-condensable tail gas is discharged, the oxidizing liquid is discharged from the stripping tower into the filter press for pressure filtration, the filtrate enters the biochemical homogeneous pool, and the pretreated effluent is adjusted to pH6 with acid or alkali in the biochemical homogeneous pool, and Mix it w...

Embodiment 2

[0043] The treatment method for the hydrazine-containing wastewater produced by the production of azodicarbonamide is as follows: the hydrazine-containing wastewater of azodicarbonamide is sent to the preprocessor through the precipitation supernatant, and lime is added to adjust the pH to 14. The tower, under the conditions of temperature 98°C, gas-liquid ratio 900, pressure 0.2MPa, and residence time of 3 hours, blows off oxidation, and the tail gas blown off at the top of the tower enters the absorption tower after defoaming, cyclone separation, and heat exchanger, and uses 80 % sulfuric acid is absorbed, non-condensable tail gas is discharged, the oxidizing liquid is discharged from the stripping tower into the filter press for pressure filtration, the filtrate enters the biochemical homogeneous pool, and the pretreated effluent is adjusted to pH9 with acid or alkali in the biochemical homogeneous pool, and mixed with Mix other industrial biochemical wastewater or urban sew...

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