Reclamation of spent glycol by treatment with alkali metal hydroxide and distillation
US4225394A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1976 |
| Grant date | Sep 30, 1980 |
| Priority date | — |
| Expiry date | Apr 14, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/582
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Ethylene glycol is recovered from spent glycol containing impurities, such as dimethyl terephthalate, by subjecting the spent glycol to a sequential flash evaporation-distillation or distillation-flash evaporation-distillation procedure. Dimethyl terephthalate impurities are rendered non-volatile by the addition of a small amount of alkali metal hydroxide prior to flash evaporation. Dewatering of spent glycol and separation of ethylene glycol from impurities rendered non-volatile by alkali metal hydroxide is also performed in one or two distillation steps. Sufficient ethylene glycol is recovered to make use of flash evaporation an optional step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.