Process for recovery of propylene and LPG from FCC fuel gas using stripped main column overhead distillate as absorber oil

US8618344B2 · kind B2 · utility

Assignee

• RELIANCE INDUSTRIES LIMITED · IN

Inventors

• Manoj Yadav · Greater Noida, IN
• Sukumar Mandal · Faridabad, IN
• Asit Kumar Das · Faridabad, IN
• Yogesh Gupta · Port Jefferson, US
• Minaz Makhania · Bhangrola, IN
• Gobind Tulsi · Jamkhed, IN
• Shailendra Arora · Jamkhed, IN
• Shubhangi Jaguste · Jamkhed, IN

Key dates

• Filing date: Jun 9, 2010
• Grant date: Dec 31, 2013
• Expiry date: Jun 9, 2030

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C10G2400/28
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process is disclosed for enhanced recovery of propylene and LPG from the fuel gas produced in Fluid catalytic cracking unit by contacting a heavier hydrocarbon feed with FCC catalyst. In the conventional process, the product mixture from FCC main column overhead comprising naphtha, LPG and fuel gas, are first condensed and gravity separated to produce unstabilized naphtha, which is subsequently used in the absorber to absorb propylene and LPG from fuel gas. However, the recovery of propylene beyond 97 wt % is difficult in this process since unstabilized naphtha already contains propylene of 5 mol % or above. In the present invention, C4 and lighter components from unstabilized naphtha are first stripped off in a separate column to obtain a liquid fraction almost free from propylene (<0.1 mol %) and other LPG components. Such a stripped liquid fraction, after cooling to 20° C. to 30° C., is used in the absorber to absorb higher amounts of propylene and LPG from fuel gas, leading to improved recovery of propylene.