Patent ID: 6623714
Filing Date: 2003-09-23
Classification: B01D,C01B,Y02P

Abstract:
A method of separating oxygen from an oxygen containing gas, said method comprising:compressing a feed stream containing said oxygen containing gas to produce a compressed feed stream; heating said compressed feed stream; heating a ceramic membrane unit to an operational temperature and forming, within the ceramic membrane unit, an oxygen permeate composed of at least a portion of the oxygen contained within the compressed feed stream and a retentate containing at least in part residual components of said compressed feed stream; cooling a process stream composed of at least a portion of the residual components of said retentate to a temperature below said operational temperature; expanding said process stream with the performance of work in an initial stage of expansion to form an expansion exhaust stream; reheating said expansion exhaust stream after said initial stage of expansion; expanding said expansion exhaust stream after having been reheated with the performance of work in a subsequent stage of expansion; the work of expansion produced by the initial stage of expansion being insufficient to meet power requirements for the compression of the feed stream, and a sum of the work of expansion of the initial and subsequent expansion stages being at least sufficient to meet said power requirements for the compression of the feed stream; applying at least part of the sum of the work of expansion of the initial and subsequent stages of expansion to the compression of the feed stream; and extracting an oxygen product stream from said ceramic membrane unit composed of said oxygen permeate.