Two stage deep naphtha desulfurization with reduced mercaptan formation

US6231753A · kind A · utility

Assignee

• Exxon Research and Engineering Company · US

Inventors

• Craig A. McKnight · Sherwood Park, CA
• Thomas R. Halbert · Baton Rouge, US
• John P. Greeley · Fairfax, US
• Garland B. Brignac · Clinton, US
• Richard A. Demmin · Highland Park, US
• William E. Winter · Baton Rouge, US
• Bruce R. Cook · Aurora, US

Key dates

• Filing date: Nov 24, 1999
• Grant date: May 15, 2001
• Expiry date: Nov 24, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C10G2400/02
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Selective and deep desulfurization of a high sulfur content mogas naphtha, with reduced product mercaptans and olefin loss, is achieved by a two stage, vapor phase hydrodesulfurization process with interstage separation of at least 80 vol. % of the H.sub.2 S formed in the first stage from the first stage, partially desulfurized naphtha vapor effluent fed into the second stage. At least 70 wt. % of the sulfur is removed in the first stage and at least 80 wt. % of the remaining sulfur is removed in the second stage, to achieve a total at least 95 wt. % feed desulfurization, with no more than a 60 vol. % feed olefin loss. The second stage temperature and space velocity are preferably greater than in the first. The hydrodesulfurization catalyst preferably contains a low metal loading of Co and Mo metal catalytic components on an alumina support.