Method for recovering propylene glycol and other organic matters from propylene epoxidation alkali washing wastewater

The invention discloses a method for recovering propylene glycol and other organic matters from propylene epoxidation alkali washing wastewater, which mainly comprises the following steps: carrying out evaporation concentration on the epoxidation alkali washing wastewater, and recovering most of water, propylene oxide and azeotropic organic matters; crystallizing the concentrated wastewater to remove organic acid salt crystals; and dehydrating and refining the obtained crude propylene glycol to obtain a propylene glycol product. When the method is used for treating the propylene epoxidation alkali washing wastewater, a medical-grade propylene glycol product can be produced; most of epoxypropane, alcohol ketone, aromatic hydrocarbon and water in the wastewater can be recycled; and in addition, the treatment cost of the organic acid salt can be greatly reduced, the amount of fuel fed into an incinerator is reduced, and the energy consumption of the device is reduced. When the method is used for treating the pro