Nitrous oxide purification system and process

US6505482B2 · kind B2 · utility

Assignees

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

Inventors

• Derong Zhou · Doylestown, US
• John Borzio · Lawrence, US
• Earle Kebbekus · Princeton, US
• David E. Miner · Chandler, US

Key dates

• Filing date: Jan 15, 2002
• Grant date: Jan 14, 2003
• Expiry date: Jan 15, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/80
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Provided are a system and method for nitrous oxide purification, wherein the nitrous oxide product is for use in semiconductor manufacturing. The system and process involve a first sub-system having a purification tank for holding a liquefied nitrous oxide, therein; a vaporizer in communication with the purification tank to receive, vaporize and convey a nitrous oxide vapor back to the purification tank; a distillation column disposed on a distal end of the purification tank to receive a nitrous oxide vapor; a condenser disposed on the distillation column, wherein light impurities are removed and wherein a nitrous oxide devoid of light impurities is conveyed and converted into vapor in the vaporizer. A second sub-system having a first dry bed vessel is disposed downstream of the vaporizer to receive the vapor and reacting the acid gas therein; a second dry bed vessel is disposed downstream of the first dry bed vessel for removing water and ammonia in the vapor. A third sub-system has a product tank wherein the purified nitrous oxide vapor is recondensed; and a transferring manifold including a liquid pump, liquid filter and a bypass for distributing the purified nitrous oxide to ho…