Production of para-xylene from an effluent from paraselective toluene disproportionation using a crystallization process combined with simulated moving bed adsorption
US5866740A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1996 |
| Grant date | Feb 2, 1999 |
| Priority date | — |
| Expiry date | Sep 27, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C7/14
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Para-xylene is produced from a paraselective toluene disproportionation reactor, effluent is distilled to eliminate toluene and benzene in at least 2 distillation columns, and the xylenes are crystallized at least once at between +10.degree. C. and -30.degree. C. The separated mother liquor is adsorbed on a zeolitic sieve in the presence of toluene in a simulated moving bed. This latter produces a raffinate containing toluene which is depleted in para-xylene which is distilled in a distillation column, and an extract which is enriched in para-xylene and contains toluene, which is recycled. The para-xylene crystals are purified by washing with toluene and distillation or by partial melting followed by washing with molten high purity para-xylene.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.