Abstract: The waste water from hydrogene peroxide propylene oxide (HPPO) process has the characteristics of large total emission, high COD, high salt content and poor biodegradability. The recovery of propylene glycol monomethyl ether and propylene glycol from HPPO wastewater was carried out by the combination of multi-stage differential pressure thermal coupling distillation technology, environment friendly recyclable azeotrope distillation technology and mechanical vapor recompression (MVR) heat pump distillation technology. The total recovery rate of high value-added products in HPPO wastewater was more than 95%, the utilization rate of propylene was increased by 3-5 percentage points, and the desalination rate was close to 100%. After the recovery of propylene glycol monomethyl ether and propylene glycol, the difficulty of wastewater treatment was greatly reduced. Under the background of energy-saving and emission-reducing, cost-reducing and efficiency-increasing in the chemical industry, it has remarkable economic and social benefits.

Key words: HPPO, propylene glycol monomethyl ether and propylene glycol recovery, propylene glycol monomethyl ether recovery