Abstract: A new three-column energy-saving technique to recover N,N-dimethylformamide（DMF）from the polyurethane（PU）synthetic leather process was developed by rebuilding a two-column recovery system. This process was composed of three columns，including first-stage vacuum concentration，second-stage atmospheric concentration，and vacuum distillation. Because heat energy was reused，the energy-saving recovery equipment could reduce energy consumption by 37.7%，compared to the current two-column equipment. No waster water was discharged in the process，and the purity of DMF product was above 99%. The profit of each energy-saving unitt could reach 4 961 900 yuan each year .

摘要： 提出了从聚氨酯合成革生产废水中回收N，N-二甲基甲酰胺的节能新工艺。该工艺充分利用现有的低压蒸汽为热媒，在现有双塔回收工艺的基础上进行改进，由一级减压浓缩、二级常压浓缩、减压精馏三塔组成，热能循环使用，比现有双塔回收装置综合能耗下降37.7％，废水可以达到零排放，所得DMF 产品的纯度99%以上。该工艺运行稳定，每套装置年收益达496.19万元。