Process for the production of paraxylene that comprises an adsorption stage, a liquid phase isomerization stage and a gas phase isomerization stage with an euo-type zeolite
US6448459B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 2000 |
| Grant date | Sep 10, 2002 |
| Priority date | — |
| Expiry date | Apr 24, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2529/72
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the production of paraxilene comprises an adsorption stage (18) using toluene as a desorbent in a simulated moving bed of a feedstock previously depleted in ethylbenzene by distillation (3) or by adsortion, an isomerization stage (26) without hydrogen in liquid phase diluted with toluene from the raffinate produced, a distillation stage (27) of the raffinate that is isomerized to recover the toluene (29) that is recycled. The separated isomerate is introduced into a xylene distillation column (9). The separated ethylbenzene is isomerized separately in gas phase with hydrogen at higher temperature and is distilled (5, 2, 9) in the presence of a catalyst that comprises an EUO-structural-type zeolite, then recycled to adsorption stage (18).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.