Method for recovering PGME and PGIE from HPPO process wastewater

By using membrane separation and azeotropic solvent substitution, the high energy consumption problem caused by the azeotropic reaction of PGME and PGIE with water in the HPPO process was solved, achieving efficient and energy-saving separation and recovery with a recovery rate of 99%.

CN121895128APending Publication Date: 2026-04-21JIANGSU RUIHENG NEW MATERIAL TECH CO LTD +1
0 Cites 0 Cited by

Patent Information

Application Number
CN202511989474.8
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2025-12-26
Publication Date
2026-04-21

AI Technical Summary

Technical Problem

During the HPPO process for producing propylene oxide, propylene glycol monomethyl ether and propylene glycol isomethyl ether, which are byproducts, are produced by azeotropic distillation with water. Existing technologies for separation via benzene azeotropic distillation are energy-intensive and pose environmental threats. Therefore, it is necessary to develop efficient, energy-saving, and environmentally friendly separation methods.

Method used

A membrane separation device is used to concentrate the HPPO process wastewater, and 2-pentanone or 3-pentanone is used as an azeotropic solvent to replace benzene. The mixture is then combined with a dehydration tower and mono- and iso-monomethyl ether towers for distillation separation, thereby reducing solvent circulation and energy consumption.

Benefits of technology

It significantly reduces dehydration energy consumption, improves the recovery rate of PGME and PGIE, meets the requirements of green and environmentally friendly processes, and the recovery rate of PGME and PGIE can reach 99%.

✦ Generated by Eureka AI based on patent content.
Patent Text Reader

Abstract

According to the method for recovering the PGME and the PGIE from the HPPO process wastewater, the HPPO process wastewater is concentrated through the membrane separation device, the content of the PGME and the PGIE in the wastewater is greatly increased, and compared with the prior art, the energy consumption can be greatly reduced, the recovery efficiency can be improved, and the recovery cost can be reduced; 2-pentanone or 3-pentanone and a mixture of 2-pentanone and 3-pentanone are used as an azeotropic solvent to replace benzene, and the solvent circulation amount in the dehydration process can be reduced by 50% under the same pressure, so that the dehydration energy consumption is remarkably reduced, and the green and environment-friendly process requirements are met; the water layer of the dehydrated fraction is recycled into the HPPO process wastewater and then is subjected to membrane separation, so that the loss of trace PGME entrained in the dehydrated fraction can be avoided, and the yield of the PGME is increased; according to the technical scheme, the recovery rates of the PGME and the PGIE can reach 99%.
Need to check novelty before this filing date? Find Prior Art