Selective para-xylene production by toluene methylation
US6423879B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1999 |
| Grant date | Jul 23, 2002 |
| Priority date | — |
| Expiry date | Nov 15, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/52
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
There is provided a process for the selective production of para-xylene which comprises reacting toluene with methanol in the presence of a catalyst comprising a porous crystalline material having a Diffusion Parameter for 2,2 dimethylbutane of about 0.1-15 sec−1 when measured at a temperature of 120° C. and a 2,2 dimethylbutane pressure of 60 torr (8 kPa). The porous crystalline material is preferably a medium-pore zeolite, particularly ZSM-5, which has been severely steamed at a temperature of at least 950° C. The porous crystalline material is preferably combined with at least one oxide modifier, preferably including phosphorus, to control reduction of the micropore volume of the material during the steaming step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.