Recovery Technology of DMF from Wet Type Polyurethane Synthetic Leather Waste Gas

A new recovery technology is developed to recycle N,N-dimethyl formamide （DMF） in waste gas from wet type polyurethane synthetic leather industry. Given that the concentration of DMF in waste gas was as low as 325.6- 688.3 mg·m^-3, it was necessary to make sure two phases contact adequately and strengthen the mass transfer by increasing contact area and enhancing the turbulence. Therefore, two-stage countercurrent absorption and two-stage fog removing system were introduced into the technology. The top section of the absorption column was filled with structured wire-ripple stainless steel packing BX500, while the lower section with sting-ripple packing CB250Y. Total height of packing material was 6 m. In addition, there were both two-stage fog removing layer and high efficiency liquid distributor at the column top. All the operating parameters, including temperature, pressure, flow rate and liquid position, could be controlled by computers without manual operation, making sure the outlet gas achieved the national emission standard that the DMF concentration should be below 40 mg·m^-3. The whole equipment could recover 237.6 t of DMF each year, with the profit up to CNY 521×10^3.

一种新恢复技术被开发再循环 N，在从湿类型聚氨酯合成皮革工业的废气的 N-dimethyl 形式酰胺(DMF ) 。给在废气的 DMF 的集中象 325.6-688.3 mg · m ~ 一样低(-3),it 是必要的保证二个阶段足够地联系并且由增加接触区域并且提高骚乱加强传质。因此，二阶段的逆流吸收和二阶段的雾搬迁系统被介绍进技术。吸收柱的最高的节充满当有包装填充材料的 CB250Y.Total 高度的圈套涟漪的更低的节是 6 m.In 增加时，包装 BX500 的结构化的电线涟漪不锈钢，两个都在柱顶有二阶段的雾搬迁层和高效率液体分发者。所有操作参数，包括的温度，压力，流量和液体放，没有手工操作，能被计算机控制，保证插头气体完成了 DMF 集中应该在 40 mg · m ~ 下面的国家排放标准(-3) 。整个设备每年能恢复 237.61 DMF，与直到 CNY 521xl03 的利润。