Appeal No. 95-4354
Application 08/137,633
The invention is directed to a method of capturing nitrogen
from air using a gas separation membrane and employing both a
high feed side air pressure and a vacuum on the permeate side to
produce high flow rates of nitrogen.
Applicant indicates that all the claims stand or fall
together. 37 C.F.R. § 1.192(c). Accordingly, we direct our
attention to claim 1 the only independent claim in the
application which reads as follows:2
1. A process for producing nitrogen gas from air at an
enhanced flow rate wherein the oxygen content of the
produced gas is 8% or less using a membrane separator,
the process comprising: (a) moving compressed air at a
pressure from about 40 psig to about 120 psig into a
membrane separator containing a plurality of hollow
fiber membranes confined in a container, the separator
being adapted to permit selectively the passage
therethrough of oxygen, carbon dioxide and water vapor
while restraining the passage of nitrogen; (b) applying
a vacuum to the permeate side of the separator of from
about 3.4 psia to about 13.2 psia to provide an
enhanced flow rate of nitrogen wherein the flow rate of
nitrogen is at least twofold higher to fourfold higher
than is observed without applied vacuum; (c) collecting
under pressure the resultant non-permeate gas from the
membrane separator.
The references relied upon by the examiner are:
McNeill 4,781,907 Nov. 1, 1988
Tsang et al. (Tsang) 4,883,023 Nov. 28, 1989
Rice 4,894,068 Jan. 16, 1990
2Claim 1 is reproduced in the brief at pages 7 and 8. In
this reproduction, claim 1, line 5, the term "containg" should
read --containing--.
2
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