Method and device for recovering mixed waste gas in synthetic leather production

Abstract

The invention discloses a method for recovering mixed waste gas in synthetic leather production, which comprises the following steps of: filtering granular matters or fibrous matters from the mixed waste gas, and cooling the mixed waste gas; absorbing the cooled mixed waste gas by circulating spraying and packing contact by using dimethyl formamide as an absorbing solvent; refrigerating the dimethyl formamide absorbing liquid which absorbs the mixed waste gas; absorbing the waste gas which is absorbed by a packing layer in a contact way by circulating water spraying and contact with water again in the packing absorbing layer; and discharging the tail gas which is absorbed by water packing and reaches the standard. The invention also discloses a recovering device for realizing the method for recovering mixed waste gas, which comprises a tower body, wherein a dimethyl formamide spraying chamber, a dimethyl formamide packing chamber, a water spraying chamber and a water packing chamber are arranged in the tower body. The invention has sufficient gas-liquid contact and high waste gas recovering rate, and not only achieves the purpose of recycling toluene, butanone and DMF but also avoids the environment pollution.

Description

technical field [0001] The invention relates to the technical field of synthetic leather production, in particular to a recovery and treatment method for mixed waste gas such as dimethylformamide, butanone, toluene and the like generated in the synthetic leather production process. The invention also relates to recycling treatment equipment applying the treatment method. Background technique [0002] Synthetic leather has been used more and more widely due to its variety of colors, changing styles, stable size, and uniform hardness. However, a large amount of volatile organic solvents are required in the production process of synthetic leather. In the production process of synthetic leather, it is first necessary to coat the base fabric with 70% dimethylformamide and 30% methyl ethyl ketone + toluene as diluents to dilute polyurethane, and then heat it at 60°C-170°C High temperature drying treatment. In this production process, a large amount of mixed waste gas containing ...

AI Technical Summary

Problems solved by technology

Because only dimethylformamide can dissolve in water in these mixed gases, while toluene is insoluble in water, butanone is slightly soluble in water, so this recovery method can only carry out recovery treatment to dimethyltetraamide (DMF), wherein Toluene and methyl ethyl ketone are still discharged into the atmosphere as waste gas

[0004] Chinese patent application "Recovery method of toluene, methyl ethyl ketone and dimethylformamide in waste gas from wet synthetic leather production", patent application number: 200410053246.1 discloses a method of secondary separation and recovery of mixed waste gas, and a method of recovery by vacuum evaporation Separating dimethylformamide from toluene and methyl ethyl ketone, this method has complex process flow, difficult operation and difficult parameter control in actual use, so it is difficult to be practically used in mixed waste gas recovery projects

Chinese patent application "Resource Treatment Method for Mixed Waste Gas", patent application number: 200610023479.6 discloses a mixed waste gas treatment method. Although the treatment method improves the recovery rate of waste gas to a certain extent, the removal recovery rate is still unstable, and due to the The absorption process of dimethylformamide (DMF) as a solvent is an exothermic process. With the continuation of the absorption process, the temperature of the solvent continues to rise, which not only leads to a rapid decrease in absorption efficiency, but also has potential safety hazards, making it difficult to mix in synthetic leather production. Practical application in exhaust gas recovery

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