Hydrocarbon upgrading process

US5399258A · kind A · utility

Assignee

• Mobil Oil Corporation · US

Inventors

• David L. Fletcher · Turnersville, US
• Michael S. Sarli · Haddonfield, US
• Stuart S. Shih · Cherry Hill, US
• Stephen J. McGovern · Mantua, US
• Douglas Diez · Deptford, US
• Mohsen N. Harandi · Lawrenceville, US
• Timothy L. Hilbert · Sewell, US

Key dates

• Filing date: Dec 10, 1992
• Grant date: Mar 21, 1995
• Expiry date: Dec 10, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C10G2300/70
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst under endothermic conditions in a second reaction zone. Heat is added to the endothermic reaction zone to initiate and maintain octane restoring reactions. The preferred acidic catalyst is an intermediate pore size zeolite such as ZSM-5. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. The addition of heat at the second zone prolongs hydrodesulfurization catalyst life by allowing a lower hydrodesulfurization reactor temperature. The addition of heat also maximizes octane increase in the second zone.