Gasoline upgrading process
US5318690A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1993 |
| Grant date | Jun 7, 1994 |
| Priority date | — |
| Expiry date | Jan 7, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10G2300/70
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Low sulfur gasoline is produced from a catalytically cracked, sulfur-containing naphtha by fractionating the naphtha feed into a low boiling fraction in which the majority of the sulfur is present in the form of mercaptans and a high-boiling fraction in which the sulfur is predominantly in non-mercaptan form such as thiophenes. The low boiling fraction is desulfurized by a non-hydrogenatile mercaptan extraction process which retains the olefins present in this fraction. The second fraction is desulfurized by hydrodesulfurization, which results in some saturation of olefins and loss of octane. The octane loss is restored by treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5, to form a low sulfur gasoline product with an octane number comparable to that of the feed naphtha but which contains some recombined sulfur in the form or mercaptans which are removed in a final hydrotreatment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.