Waste gas treatment process and device in spandex production process

Abstract

The invention relates to a waste gas treatment process and device in a spandex production process. Waste gas in the spandex production process is introduced into adsorption towers; a hydrophobic adsorbent in the towers adsorbs the waste gas; tail gas is emptied from the tower tops of the adsorption towers; the adsorption towers comprise a first adsorption tower and a second adsorption tower whichare connected in parallel; after the first adsorption tower is used for adsorbing to be saturated, the waste gas enters the second adsorption tower to be adsorbed, and when the waste gas is absorbed in the second adsorption tower, the first adsorption tower is regenerated; the process includes vacuum desorption, condensation liquefaction and pickling. An adsorption / desorption process, a condensation process and an acid absorption process are combined for treating spandex waste gas; the odor concentration of the spandex waste gas can be reduced from more than or equal to 10000 to less than or equal to 100 and is greatly lower than the national waste gas emission standard; meanwhile, the two adsorption towers are used for alternative adsorption and regeneration, the waste gas treatment process is continuously operated, energy conservation and consumption reduction are realized, the treatment cost is reduced, and certain economic benefits are achieved.

Description

technical field [0001] The invention belongs to the technical field of waste gas treatment, and in particular relates to a process and device for treating waste gas in the spandex production process. Background technique [0002] Nitrogen-containing organic compounds such as dimethylamine, N,N-dimethylacetamide, and N,N-dimethylformamide will be produced in the spandex production process, mainly from solvent volatilization in the tunnel and N,N- Decomposition of dimethylacetamide. Among them, the molecular formula of dimethylamine: C 2 h 7 N. Boiling point (°C): 7.0. It is a colorless gas at room temperature. It smells like ammonia at high concentrations, and smells like rotten fish at low concentrations. The olfactory threshold in air is 0.047ppm. Dimethylamine is irritating to human respiratory tract, eyes, skin, etc. Long-term exposure will affect human health. [0003] At present, the tail gas treatment in the spandex industry mainly adopts the multi-stage water spra...

AI Technical Summary

Problems solved by technology

The stripping method has low treatment efficiency and is mainly suitable for high-concentration gases. The low-temperature plasma method and the ultraviolet photocatalytic oxidation method have similar principles. The active groups generated react with dimethylamine and are oxidized into NOx, causing secondary pollution; directly The acid absorption method will produce a large amount of acid-containing wastewater, which will seriously affect the subsequent biochemical treatment of sewage; the activated carbon adsorption method will absorb water and be easily saturated.

[0005] Chinese patent CN 102343205A discloses a process and device for centralized purification of waste gas in the production process of spandex, specifically: the waste gas passes through the absorption tower, passes through the composite solution absorption unit and the organic acid solution absorption unit in turn, and then is emptied from the top of the absorption tower. In this process, first use the composite solution absorption unit to absorb the gas easily soluble in water and lye in the exhaust gas, such as dimethylformamide, dimethylacetamide, acetic acid, formaldehyde, etc., and also absorb part of dimethylamine and ammonia gas, and then absorbed again through the organic acid solution absorption unit to remove the remaining alkaline and water-soluble harmful gases; the waste gas in the production process of the patented spandex is absorbed by a composite solution and an organic acid solution, which will produce a large amount of waste water, causing secondary pollution

[0006] Chinese patent CN 108554172A discloses a dimethylamine waste gas treatment device and its process in the synthetic leather industry. The dimethylamine waste gas enters the buffer box, the first-level capture tower, the second-level capture tower, the photoelectric integrated purifier, and the nano-absorption tower in turn. , and finally the gas from the nano-absorption tower is discharged at an altitude of 20 meters through the exhaust pipe. Among them, the first-level capture tower and the second-level capture tower are the same equipment, both of which include two-stage spraying layers, and the top spraying system of the two-stage spraying layers An aqueous solution with inorganic acid is added to absorb dimethylamine waste gas; the remaining part of dimethylamine waste gas after being treated by the primary and secondary capture towers enters the photoelectric integrated purifier and then passes through the plasma reaction section and the photocatalytic reaction section in turn, and the plasma discharge process The generated high-energy electrons and active substances degrade VOCs; in this patent, the spray equipment of inorganic acid aqueous solution is used for absorption, which will generate a large amount of waste water discharge, and the plasma reaction section and photocatalytic reaction will degrade the dimethylamine waste gas, that is, by producing The active groups of the active groups react with dimethylamine to generate NOx, and the above two exhaust gas treatment methods will cause secondary pollution

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