Ex Parte Lane et al

Patent Trial and Appeal Board

Mar 7, 2013

11111837 (P.T.A.B. Mar. 7, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/111,837 04/22/2005 Jonathan Andrew Lane 21498 4947
27182 7590 03/08/2013
PRAXAIR, INC.
LAW DEPARTMENT - M1-04
39 OLD RIDGEBURY ROAD
DANBURY, CT 06810-5113
EXAMINER
COX, ALEXIS K
ART UNIT PAPER NUMBER
3744
MAIL DATE DELIVERY MODE
03/08/2013 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________________

Ex parte JONATHAN ANDREW LANE,
DANTE PATRICK BONAQUIST, ERIC SHREIBER, and
BAYRAM ARMAN
____________________

Appeal 2011-000413
Application 11/111,837
Technology Center 3700
____________________

Before: WILLIAM V. SAINDON, SCOTT A. DANIELS, and
BEVERLY M. BUNTING, Administrative Patent Judges.

SAINDON, Administrative Patent Judge.

DECISION ON APPEAL
Appeal 2011-000413
Application 11/111,837
2
STATEMENT OF THE CASE
Appellants appeal under 35 U.S.C. § 134 from the Examiner’s
decision rejecting claims 1-20. We have jurisdiction under 35 U.S.C. § 6(b).

The Claimed Subject Matter
Claim 1, reproduced below with added emphasis, is illustrative of the
claimed subject matter.
1. A method of purifying a gas stream by removing oxygen
from said gas stream, said method comprising:
introducing said gas stream into a series of electrically
driven oxygen separation zones operating an elevated
temperature to separate the oxygen from the gas stream, thereby
to produce a purified gas stream;
each of the electrically driven oxygen separation zones
having an electrolyte and cathode and anode assemblies for
applying a voltage to the electrolyte such that the oxygen ions
are transported through the electrolyte and emerge therefrom to
recombine into elemental oxygen, thereby to separate the
oxygen from the gas stream;
the oxygen being separated from the gas stream at a
successively lower partial pressure due to the separation of the
oxygen within successive electrically driven oxygen separation
zones;
each of the electrically driven oxygen separation zones
being capable of separating the oxygen as an increasing
function of the voltage applied to the cathode and anode
assemblies up to a level that induces an oxygen ion current that
approaches a limiting oxygen ion current within the electrically
driven oxygen separation zones at which a further increase in
the voltage fails to produce an increase in oxygen separation,
the limiting oxygen ion current limit being a function of the
successively lower partial pressure such that the voltage applied
decreases for each of the successive electrically driven oxygen
separation zones; and
applying the voltage to each of the electrically driven
oxygen separation zones in an amount selected such that the
Appeal 2011-000413
Application 11/111,837
3
oxygen ion current approaches the limiting oxygen ion current
applicable thereto and that decreases in each of the successive
electrically driven oxygen separation zones.

Rejections
I. Claims 1 and 4-11 are rejected under 35 U.S.C. § 103(a) as
unpatentable over Nachlas (US 5,454,923, iss. Oct. 3, 1995). Ans. 4.
II. Claims 2-3 and 12-20 are rejected under § 103(a) as unpatentable over
Nachlas and Prasad (US 5,557,951, iss. Sep. 24, 1996). Ans. 7.

SUMMARY OF DECISION
We AFFIRM.

OPINION
Sole independent claim 1 requires a plurality of electrically driven
oxygen separation zones, used to purify a gas stream. Claim 1 further
requires that the voltage applied to each of these zones decreases
successively and that the voltage is set at a limiting oxygen ion current
value1.
The Examiner found that Nachlas describes a gas purification system
using a series of electrically driven oxygen separation zones. Ans. 4. The
Examiner found that Nachlas describes using different electrolyte materials
in the subsequent oxygen separations zones, such that the second stage

1 The Nernst equation (formulated by Walther Nernst, 1864-1941), describes
the relationship between a concentration gradient and the electric gradient
that balances it. Nachlas, col. 1, l. 20 et seq. As a corollary, at a certain
voltage level, increased voltage no longer drives much additional oxygen
across a concentration barrier. See id.; see also id., figs. 1-2. Appellants
have chosen to label this concept “limiting oxygen ion current.” Spec.,
paras. [0009], [0033], fig. 2.
Appeal 2011-000413
Application 11/111,837
4
oxygen separator operates at a higher voltage than the first. Ans. 5. The
Examiner concluded, however, that it would have been obvious to use a
common material in the multiple stages of Nachlas, to have “lower
maintenance costs, as well as a possible reduction in construction cost and
equipment downtime.” Id. Given the knowledge of one of ordinary skill in
relating voltage to oxygen removal, and the fact that there is a lower partial
pressure of oxygen in subsequent stages, the Examiner concluded that the
subsequent stages would be operated at the limiting oxygen ion current such
that the voltage applied would be decreasing. Ans. 4-5, 10-14; see also
Nachlas, figs. 2-3; Fin. Rej. 11 (mailed Sep. 29, 2009) (“the highest useful
applied voltage goes down with partial pressure of oxygen”).
Appellants argue claims 1 and 9-11 as a group. App. Br. 15. We
select claim 1 as representative. Appellants first argue that Nachlas does not
discuss applying decreasing voltages in successive zones. App. Br. 11-12.
However, the Examiner’s rejection is not predicated on a finding that
Nachlas discloses as much. Ans. 4-5, 10-12. As set forth above, the
Examiner offered a reason and rational underpinnings to support the
conclusion that it would have been obvious to modify Nachlas such that the
same material is used in successive zones and has explained how this leads
to decreasing voltages; Appellants have not apprised us of error in the
Examiner’s position.
Appellants also argue that Nachlas does not disclose or suggest using
the same material for the successive zones. App. Br. 12-14. As above,
however, this argument is not responsive to the rejection as set forth by the
Examiner. See Ans. 4-5, 13-14. The Examiner offered a reason and rational
underpinnings to modify Nachlas such that the same material is used in
Appeal 2011-000413
Application 11/111,837
5
successive zones. Appellants do not apprise us of error in the Examiner’s
position.
Having reviewed the entirety of Appellants’ arguments with respect to
claim 1, we are not apprised of error in the Examiner’s rejection. We sustain
the rejection of claim 1; claims 9-11 fall therewith.
With respect to claims 4-6, Appellants argue that Nachlas does not
describe purifying a crude nitrogen stream “withdrawn from a pressure
swing adsorption apparatus.” App. Br. 14. Again, however, the Examiner’s
rejection is not predicated on such a finding, but rather a conclusion that it
would have been obvious to perform Nachlas’s nitrogen purification from
such a source. Ans. 6, 14-15. The Examiner offered a reason and rational
underpinnings for this conclusion, and Appellants do not apprise us of error.
Accordingly, we sustain the Examiner’s rejection of claims 4-6.
Appellants separately argue claims 7 and 8, but as above, Appellants
generally allege error and do not point to the error in the Examiner’s
rejection. Compare App. Br. 15 with Ans. 6, 15. We sustain the rejection of
claims 7 and 8.
Appellants argue claims 2, 3, 13-17, 19, and 20 as a group and note
that these claims are “allowable on the same basis as claim 1.” App. Br. 16.
Because we are not apprised of error in the rejection of claim 1, we sustain
the rejection of these claims as well.
Appellants separately argue claim 12. Appellants argue, “there is no
suggestion in either of the references” to perform the modification proposed
by the Examiner. App. Br. 16. However, the Examiner offered a reason and
rational underpinning in support of the conclusion made. Ans. 7-8, 16.
Appellants do not point to error in the Examiner’s rejection, and furthermore
there is no legal requirement that the Examiner’s reasoning or rationale be
Appeal 2011-000413
Application 11/111,837
6
predicated on a “suggestion in … the references.” See KSR Int’l Co. v.
Teleflex, Inc., 550 U.S. 398, 419 (2007) (“The obviousness analysis cannot
be confined by a formalistic conception of the words teaching, suggestion,
and motivation, or by overemphasis on the importance of published articles
and the explicit content of issued patents.”). Accordingly, we sustain the
rejection of claim 12.
Appellants’ separate argument for claim 18 is deficient for the same
reasons as those for claim 12. Compare App. Br. 16-17 with Ans. 10, 16-17.

DECISION
We AFFIRM the Examiner’s decision regarding claims 1-20.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED

hh