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Method of Repressurising the Pretreatment PSA of a Cryogenic Air Separation Unit

IP.com Disclosure Number: IPCOM000019388D
Publication Date: 2003-Sep-12

Publishing Venue

The IP.com Prior Art Database

Abstract

Cryogenic air separation units (ASUs) generally use a pair of adsorbers to remove contaminants from the feed air, such as water vapour or carbon dioxide, which would freeze out in the downstream cryogenic equipment. The use of pressure swing adsorbers (PSAs) for this duty can be the preferred technology. A PSA does not require regeneration gas heating; and it does not require feed air chilling, owing to its relative insensitivity to feed air temperature. Unfortunately the short cycle time, and hence the necessary rapid repressurisation time of a PSA, can result in adverse switch pressure effects on the downstream cryogenic equipment during the changeover period of the 2 PSA vessels.