Cryogenic distillation method and system for air separation

US7464568B2 · kind B2 · utility

Assignee

• L'Air Liquide, Société Anonyme à Directoire et Conseil de Surveillance pour l'Étude et l'Exploitation des Procédés Georges Claude · FR

Inventors

• Patrick Le Bot · Saint-Mandé, FR
• Olivier De Cayeux · Nogent-sur-Marne, FR

Key dates

• Filing date: Mar 24, 2004
• Grant date: Dec 16, 2008
• Expiry date: Dec 5, 2024

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F25J2240/04
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Methods and apparatus for air separation by cryogenic distillation in a double or triple air separation column. The column in the system with the highest operating pressure is said to be operating at medium pressure. All the air to be distilled is pressurized to a high pressure, which is about 5 bar greater than the medium pressure. The air is purified at this high pressure, and a portion of the purified air is cooled in a heat exchange line, while another portion is expanded in a turbine. Part of the cooled air is drawn from the exchange line with a cold booster, which is mechanically coupled to at least one turbine. An energy dissipation device is also provided which is coupled to the turbine not coupled to the cold booster. The energy dissipation device is either another booster, an oil break system, or an electrical generator.