The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 07, 1995
Filed:
Aug. 12, 1994
Ravi Kumar, Allentown, PA (US);
William T Kleinberg, Breingsville, PA (US);
Air Products and Chemicals, Inc., Allentown, PA (US);
Abstract
An integrated adsorption/cryogenic distillation process is set forth for the separation of an air feed. The air feed is passed through a vacuum swing adsorption (VSA) unit to remove impurities comprising water and carbon dioxide which will freeze out at cryogenic temperatures. The VSA sequence includes an adsorbent regeneration step whereby the impurity-saturated adsorbent is purged under vacuum with a purge gas. The resulting impurity-depleted air feed is fed to a cryogenic distillation column for rectification into a gaseous nitrogen overhead and a liquid oxygen bottoms. A waste stream from the distillation column is expanded, warmed against the impurity-depleted air feed to recover its refrigeration and subsequently recycled as the purge gas to the VSA unit. A key to the present invention is that the waste stream is expanded to the required sub-ambient pressure level in the cryogenic portion of the process. This enables one to recover all of the available refrigeration from the cryogenic waste stream prior to using such waste stream as the purge gas for the adsorption portion of the process.