Benzene conversion in an improved gasoline upgrading process
US5865987A · kind A · utility
Inventors
Key dates
| Filing date | May 23, 1997 |
| Grant date | Feb 2, 1999 |
| Priority date | — |
| Expiry date | May 23, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10G69/123
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Low sulfur gasoline is produced from an olefinic, cracked, sulfur-containing naphtha by treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5 to crack low octane paraffins and olefins under mild conditions with limited aromatization of olefins and naphthenes. A benzene-rich co-feed is co-processed with the naphtha to reduce the benzene levels in the co-feed by alkylation. This initial processing step is followed by hydrodesulfurization over a hydrotreating catalyst such as CoMo on alumina. In addition to reducing benzene levels in the combined feeds, the initial treatment over the acidic catalyst removes the olefins which would otherwise be saturated in the hydrodesulfurization, consuming hydrogen and lowering product octane, and converts them to compounds which make a positive contribution to octane. Overall liquid yield is high, typically at least 90 percent or higher. Product aromatics are typically increased by no more than 25 weight percent relative to the combined feeds and may be lower than the feed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.