Process for separating paraxylene comprising at least two crystallization stages at high temperature
US6147272A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1997 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Jun 30, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C7/14
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for producing paraxylene of very high purity from a charge containing a mixture of aromatic hydrocarbons having 7 to 9 carbon atoms in which at least a portion of the charge is made to circulate in a zone suited to enrich a first fraction of paraxylene and at least a portion of said first fraction is purified by at least one high-temperature crystallization in at least one crystallization zone, the process being characterized in that said first paraxylene-enriched fraction is crystallized in a crystallization zone comprising at least two crystallization stages (50,70) at high temperature, and advantageously between +10 and -25 .degree. C. The paraxylene enriching zone can be a crystallization at very low temperature, a selective adsorption or a toluene disproportionation zone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.