Method for distilling a gas stream containing oxygen

US11291946B2 · kind B2 · utility

Assignee

• L'Air Liquide, Societe Anonyme Pour l'Etude et l'Exploitation des Procedes Georges Claude · FR

Inventors

• Paul Terrien · Newton, US
• Nicolas CHANTANT · Grenoble, FR

Key dates

• Filing date: Dec 17, 2018
• Grant date: Apr 5, 2022
• Expiry date: Dec 17, 2038

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E50/30
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for producing biomethane by scrubbing a biogas feed stream includes introducing the feed gas stream into a pretreatment unit wherein a CO2-depleted gas stream is partially separated from a CO2 stream and an oxygen stream and is compressed to a pressure P1 above 25 bar abs. Subjecting the CO2-depleted gas stream to cryogenic separation in a distillation column to separate a nitrogen stream and produce a CH4-enriched stream, the distillation column comprising n plates, n being an integer between 8 and 100. Recovering a pressurized CH4-enriched stream by pumping the CO2-depleted gas stream to a pressure P2 above 25 bar absolute.