Method and catalyst system for improving benzene purity in a xylenes isomerization process
US10265688B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 2016 |
| Grant date | Apr 23, 2019 |
| Priority date | — |
| Expiry date | Nov 11, 2036 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/52
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process and catalyst system is disclosed for producing para-xylene from a C8 hydrocarbon mixture comprising ethylbenzene and at least one xylene isomer other than para-xylene. The process modifies the conventional process by operating with a higher weight hourly space velocity, lower pressure and lower hydrogen partial pressure, which allows production of on-specification benzene product without penalty with respect to ethylbenzene conversion, para-xylene approach to equilibrium or xylene losses. The catalyst system comprises a first catalyst bed comprising a first zeolite having a constraint index from 1 to 12 and an average crystal size from 0.1 to 1 micron and a platinum hydrogenation component, and a second catalyst bed comprising a second zeolite having a constraint index ranging from 1 to 12 and an average crystal size of less than 0.1 micron and a rhenium hydrogenation component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.