Process for co-production of metaxylene and paraxylene
US6359186B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1999 |
| Grant date | Mar 19, 2002 |
| Priority date | — |
| Expiry date | Aug 25, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C7/12
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
For co-production of metaxylene and paraxylene from a feedstock (line-4) of hydrocarbons, there is employed a simulated moving bed chromatographic column 5 having at least five zones and which delivers an extract, a raffinate and an intermediate raffinate. The feedstock has an ethylbenzene content of less than 5% by weight, and the chromatographic column comprises at least twenty-five beds, of which at least five beds are in zone 3B. The raffinate is distilled (31) to recover the metaxylene at a purity of at least 99% and orthoxylene. The extract is distilled (7, 10) to recover the paraxylene at a purity of at least 99.6%. The recovered isomers can be synthesized into isophthalic acid and terephthalic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.