Method for separating a natural gas stream into a methane-enriched fraction and a fraction enriched in C2 and higher hydrocarbons

US11278843B2 · kind B2 · utility

Assignees

• L'Air Liquide, Societe Anonyme Pour l'Etude et l'Exploitation des Procedes Georges Claude · FR
• Air Liquide Advanced Technologies U.S. LLC · US

Inventors

• Paul Terrien · Newton, US
• Pascal Marty · Bry-sur-Marne, FR
• Yong Ding · Newton, US

Key dates

• Filing date: Jul 23, 2018
• Grant date: Mar 22, 2022
• Expiry date: Dec 3, 2038

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F25J2245/02
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for purifying a feed gas including methane and heavy hydrocarbons, including: step a): cooling the feed gas in a heat exchanger; step b): introducing the resulting into a first phase separator to produce a liquid stream depleted in methane and enriched in heavy hydrocarbons and a gas stream; step c): separating the gas stream in a membrane from which a methane-enriched permeate stream and a partially condensed residue stream exit; step d): introducing the residue stream from step c) into a second phase separator vessel in order to produce a liquid stream and a gas stream; step e): introducing at least one portion of the gas stream resulting from step d) into a JT expansion means; and step f): heating at least one portion of the expanded stream in the heat exchanger used in step a) counter-current to the feed stream in order to cool the latter.