Synthetic leather production process waste gas treatment method

A production process and treatment method technology, applied in gas treatment, separation methods, chemical instruments and methods, etc., can solve the problems of large water consumption and waste liquid discharge, low absorption efficiency of packed towers, complex process flow, etc.

Active Publication Date: 2021-04-23
浙江金潮实业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the basic method of absorbing waste gas in the dry production process of synthetic leather is mainly collected by DMF absorption tower, and this method of using DMF absorption tower for collection can only be used to collect DMF waste gas. After collecting DMF waste gas at this stage Other waste gas treatment methods are more troublesome, and the wettability of the packing is low under the condition of very low liquid distribution density, which will lead to low absorption efficiency of the packed tower. None of them can ensure the high wettability of the packing and improve the absorption efficiency It is a method to reduce the distillation load and cost of waste liquid at the same time, and when absorbing DMF waste gas, there are problems such as complicated process flow, more thorough packing cleaning of viscous substances, large water consumption and waste liquid discharge, and high cost of distilled water. Except for DMF In addition, there are other components of waste gas. If only the recovery of DMF is considered in the production process, the discharge of other waste gases will not meet the environmental protection requirements, and further treatment is required.

Method used

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  • Synthetic leather production process waste gas treatment method
  • Synthetic leather production process waste gas treatment method
  • Synthetic leather production process waste gas treatment method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] at 40000m 3 / h, 100℃, 4500mg / m 3 DMF, other components 500mg / m 3 Take the single line as an example, the outlet temperature of the refrigerated spray circulating fluid is considered as 27°C, the refrigeration coefficient is considered as 8, and the standard gas volume of waste gas is 29276m 3 / h, the cooling condensing load is Q=550000kcal / h, the heat exchange surface of the cooler is about 350㎡, the cooling fan is 3kw, the circulating water pump is 5.5kw, the refrigeration load is 100000kcal / h, equipped with a 20t / h cooling tower, and the power of the refrigerator is 18.5 kw, fan pressure 4000Pa, air volume 33000m 3 / h, power 55kw, circulating spray pump 5.5kw, desorption fan 2500Pa, 3600m 3 / h, the power is 5.5kw, the total installed power of the system is 93kw, and the power consumption per hour is 79 degrees according to the demand coefficient of 0.85.

[0047] The cooling condenser adopts a large tube outer film evaporative condenser. In order to increase the ...

Embodiment 2

[0052] In the usual chemical absorption process, the pure absorbent is added to the top of the tower and the waste gas through the liquid distributor for pure counterflow mass transfer absorption, so that there is the greatest mass transfer and absorption driving force (effective maximum mass transfer concentration difference), but due to DMF water soluble The performance is very good, and the water consumption of the dry-process synthetic leather waste gas absorption packed tower is very small. In such a small water distribution (0.15m 3 / ㎡.h) The very poor wettability of the filler will also affect the absorption efficiency, so the dry absorption tower currently in use adopts a 3-stage or 4-stage circulation process, although the absorption liquid circulation destroys part of the absorption mass transfer concentration difference , but it can ensure the wettability of the filler, and the absorption effect is also good. Usually, there are 3 stages of circulation. Under the work...

Embodiment 3

[0057] The above-mentioned embodiment 2 only considers the recovery of DMF, if the waste gas is preferentially collected at 5000mg / m 3 , remove most of DMF at 4400-1600mg / m 3 , still have 500mg / m 3 Left and right other harmful solvent components are far from meeting the emission standards and need to be further treated. However, if only the 3rd or 4th section of the dry absorption tower is used, the temperature of the exhaust gas reaches the top of the tower as high as 37 ° C, and the relative humidity is as high as 95%. The subsequent adsorption and concentration efficiency is affected to a certain extent, even if the hydrophobic zeolite concentration runner is used, the purification efficiency is 60-70%, and the cost of this method is too high; if the concentrator efficiency of the lower cost activated carbon fiber is only 50- 60%; if the temperature drops to 35°C and the relative humidity drops to about 50%, it needs to be treated with a refrigerated dehumidifier. Although...

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Abstract

The invention discloses a synthetic leather production process waste gas treatment method. The method comprises the following steps: first waste gas absorption of four-stage circulation of spray washing, and first cooling and condensing and subsequent freezing; The first waste gas absorption of four-stage circulation of spray washing comprises the following operations: centrally collecting waste gas, centrally collecting the mixed waste gas with the temperature of 90-110 DEG C generated by a synthetic leather processing technology, and centrally collecting mixed waste gas with the concentration of 4900-5100mg / m<3>, wherein in the mixed waste gas components, DMF accounts for 4400-4600mg / m<3> and other waste gas components account for 400-600mg / m<3>; and after the concentration of the formed mixed waste gas reaches 5000 mg / m<3>, the mixed waste gas is filtered through a reverse osmosis membrane filter screen to remove part of solids and viscous substances, then first cooling condensation and subsequent freezing treatment is conducted in cooperation with a cooling tower, and the first cooling condensation and subsequent freezing treatment is divided into cooling condensation treatment and freezing treatment, wherein the cooling condensation treatment comprises the step of condensing waste gas by using a spray cooler outside the pipe to obtain high-concentration waste liquid with the concentration of 70-80% and the temperature of 40-50 DEG C.

Description

technical field [0001] The invention relates to the field of environmental protection, in particular to a method for treating waste gas in the production process of synthetic leather. Background technique [0002] The PU resin used in the production process of synthetic leather is dissolved in an organic solvent. The solvent is mainly composed of DMF (N, N-dimethylformamide), toluene and butanone. In wet production, DMF is washed in water and dried. DMF is volatilized into the hot air in the oven during the production process. If the washing water of the wet process and the hot air of the dry process are discharged directly, it will not only waste DMF, but also pollute the environment. At present, the DMF wastewater in the wet production line has been basically recovered. While protecting the environment, it can also increase economic benefits by recycling waste gas. The hot air discharged from the dry production line is also basically collected and treated. During the dry p...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D53/00B01D47/06B01D53/18B01D53/14B01D53/04
CPCB01D53/002B01D47/06B01D53/18B01D53/1487B01D53/1412B01D53/04B01D2258/02B01D2252/103B01D2257/40B01D2253/102B01D2259/40086Y02A50/20
Inventor 苏维星王超林孙张廖建华魏侯勇
Owner 浙江金潮实业有限公司
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