Ex Parte Kearl et al

Board of Patent Appeals and Interferences

Jul 23, 2009

10282358 (B.P.A.I. Jul. 23, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte DANIEL A. KEARL, RICHARD B. PETERSON,
and MONTE KEVIN DROST
____________

Appeal 2009-001249
Application 10/282,358
Technology Center 1700
____________

Decided:1 July 23, 2009
____________

Before TERRY J. OWENS, CATHERINE Q. TIMM, and
JEFFREY B. ROBERTSON, Administrative Patent Judges.

ROBERTSON, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, begins to run from the Decided Date
shown on this page of the decision. The time period does not run from the
Mail Date (paper delivery) or Notification Date (electronic delivery).

Appeal 2009-001249
Application 10/282,358

Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1-8, 36, 37, 39-41, 45, and 47-56.2 (App. Br. 4). We
have jurisdiction pursuant to 35 U.S.C. § 6(b).
We AFFIRM.
THE INVENTION
Appellants describe a fuel cell including a heat exchanger that is said
to allow the fuel cell to reach a start-up temperature more rapidly. (Spec.
[0030]). Claims 1, 4, 41, and 45, reproduced below, are representative of the
subject matter on appeal.
1. A fuel cell comprising:

a fuel cell stack for receiving reactants and conducting a
reaction to produce an electrical current;

a catalytic combustor, connected to said fuel cell stack,
configured for receiving and combusting reactants, including a
fuel and an oxidant, that pass un-reacted through said fuel cell
stack, wherein said catalytic combustor comprises a catalyst for
facilitating combustion of said reactants that were not reacted
by said fuel cell: and

a heat exchanger for exchanging heat from an exhaust of
said catalytic combustor to increase a temperature of the
reactants closer to a light-off temperature as said reactants are
received by said fuel cell stack.

4. The fuel cell of claim 1, further comprising a heating
element for heating said catalytic combustor and reactants in
said catalytic combustor.

2 Claims 9-34 have been canceled. Claims 35, 38, 42-44, and 46 have been
withdrawn from consideration. (Appeal Brief filed January 22, 2008,
hereinafter “App. Br.,” 4).
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41. The fuel cell of claim 1, further comprising a mixer
connected to said heat exchanger, wherein said mixer cools
gases exiting said heat exchanger before said gases are
exhausted to an ambient environment.

45. A fuel cell comprising:

a fuel cell stack for receiving reactants and conducting a
reaction to produce an electrical current;

a catalytic combustor, connected to said fuel cell stack,
configured for receiving and combusting reactants, including a
fuel and an oxidant, that pass un-reacted through said fuel cell
stack, wherein said catalytic combustor comprises a catalyst for
facilitating combustion of said reactants that were not reacted
by said fuel cell; and

a heat exchanger for exchanging heat from an exhaust of
said catalytic combustor to increase a temperature of the
reactants received by said fuel cell stack;

wherein said fuel and oxidant enter said catalytic
combustor through fuel inlets and oxidant inlets located in a
same wall of said catalytic combustor.

THE REJECTIONS
The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Baker 3,522,101 July 28, 1970
DeFreitas 5,695,328 Dec. 9, 1997
Nikkanen 6,106,229 Aug.22, 2000
Dibble US 6,269,625 B1 Aug. 7, 2001
Griesmeier US 2001/0028968 A1 Oct. 11, 2001
Kurita US 6,306,532 B1 Oct. 23, 2001
Yabuuchi US 6,394,789 B1 May 28, 2002
Kelly US 6,608,462 B1 Aug. 19, 2003
(filed June 24, 2002)
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Application 10/282,358

There are seven grounds of rejection under 35 U.S.C. § 103(a) for
review on appeal: (1) the Examiner rejected claims 1-3, 45, and 47 as being
unpatentable over Kurita in view of Griesmeier; (2) the Examiner rejected
claims 4, 5, 37, and 51-53 as being unpatentable over Kurita in view of
Griesmeier, and further in view of Dibble; (3) the Examiner rejected claims
6-8, 48, and 49 as being unpatentable over Kurita in view of Griesmeier, and
further in view of Kelly; (4) the Examiner rejected claims 36 and 50 as being
unpatentable over Kurita in view of Griesmeier, and further in view of
Yabuuchi; (5) the Examiner rejected claims 39 and 55 as being unpatentable
over Kurita in view of Griesmeier, Dibble, and further in view of DeFreitas;
(6) the Examiner rejected claims 40 and 54 as being unpatentable over
Kurita in view of Griesmeier, Dibble, and further in view of Baker; and (7)
the Examiner rejected claims 41 and 56 as being unpatentable over Kurita in
view of Griesmeier, and further in view of Nikkanen.

Rejection of claims 1-3, 45, and 47 over Kurita in view of Griesmeier
In rejecting the claims on appeal, the Examiner found that Kurita
teaches a fuel cell including a combustor that is configured to receive
unreacted fuel and air separately, but in the same wall of the combustor, and
where the exhaust of the combustor is fed to a heat exchanger to heat the
fuel and the air as they are received by the fuel cell stack. (Examiner’s
Answer entered April 4, 2008, hereinafter “Ans.,” 3). The Examiner found
that Kurita does not disclose the type of combustor that is used. (Id.). The
Examiner found that Griesmeier discloses a fuel cell including a catalytic
combustor and determined that it would have been obvious to include
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Griesmeier’s catalytic combustor in the fuel cell of Kurita in order to
improve the overall efficiency of the system. (Ans. 3 and 4).
Appellants do not dispute the Examiner’s conclusion that it would
have been obvious to include a catalytic combustor in Kurita as taught by
Griesmeier. Rather, Appellants dispute the Examiner’s finding that Kurita
discloses that the fuel and air are heated by the heat exchanger as they are
received by the fuel cell stack. Appellants contend that in Kurita the
combustion gas heat is used to drive a turbine compressor, and therefore
when entering Kurita’s heat exchanger the combustion gas no longer has
sufficient thermal energy to increase the temperature of the fuel cell
reactants. (App. Br. 10 and 11). Appellants point to Kurita’s disclosure that
the temperature of inlet gas pipes is “maintained” for support and that the
temperature of the fuel cell reactants is not increased by the heat exchanger.
(App. Br. 11 and 12).

ISSUES
The issues are:
Have Appellants shown that the Examiner reversibly erred in
determining that Kurita discloses a heat exchanger that increases the
temperature of reactants as the reactants are received by the fuel cell stack?
Have Appellants shown that the Examiner reversibly erred in
determining that Kurita discloses that fuel and oxidant enter the catalytic
combustor through inlets located in the same wall of the catalytic
combustor?

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FINDINGS OF FACT
The record supports the following findings of fact (FF) by a
preponderance of the evidence.
1. Kurita describes a fuel cell system including a combustor and a
turbine compressor, where the high temperature combustion gas
exhaust drives a turbine unit of the turbine compressor to rotate.
(Col. 6, ll. 6-24).
2. Kurita’s Figure 1 is reproduced below:

Figure 1 depicts a block diagram of a fuel cell system including
combustor 1, turbine compressor 2, with turbine unit 21, fuel cell 4, heat
exchanger 5, exhaust air line 61, reformed gas line 62, reformed gas line
63, and supply air line 64. (Col. 6, ll. 6-38).
3. Kurita’s Figure 1 depicts exhaust air line 61 and reformed gas line
62 entering the combustor from inlets located in the same wall of
the combustor. (See FF 2).
4. Kurita discloses:
heat of combustion exhaust gas exhausted from the
combustor, heat of humidifying water from the
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humidifying apparatus and heat of oxygen, (air) as an
oxidant gas for fuel gas from the compressor unit are
exchanged by heat exchangers. This enables sufficient
heat exchange and stable operation of the fuel cell.

(Col. 2, ll. 50-56).

PRINCIPLES OF LAW
Appellants have the burden on appeal to the Board to demonstrate
error in the Examiner's position. See In re Kahn, 441 F.3d 977, 985-86 (Fed.
Cir. 2006) (“On appeal to the Board, an applicant can overcome a rejection
[under § 103] by showing insufficient evidence of prima facie obviousness
or by rebutting the prima facie case with evidence of secondary indicia of
nonobviousness.”) (quoting In re Rouffet, 149 F.3d 1350, 1355 (Fed. Cir.
1998)).

ANALYSIS
Appellants have grouped claims 1 and 45 subject to the first ground of
rejection separately. However, Appellants rely on essentially the same
arguments for claims 1 and 45. Accordingly, we confine our discussion to
appealed claim 1, which contains claim limitations representative of the
arguments made by Appellants, and address claim 45 only to the extent that
Appellants have argued it separately pursuant to 37 C.F.R.
§ 41.37(c)(1)(vii).3 Appellants have not presented separate arguments for

3 Only those arguments actually made by Appellants have been considered in
this decision. Arguments which Appellants could have made but chose not
to make have not been considered and are deemed to be waived. See 37
C.F.R. § 41.37(c)(1)(vii) (2007).
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the grounds of rejection three through six. Accordingly, our comments with
respect to the first ground of rejection apply equally to grounds of rejection
three through six.
We agree with the Examiner that Appellants have failed to
demonstrate that Kurita’s heat exchanger is incapable of heating the
reactants being fed to the fuel cell stack even by one degree. (Ans. 8-9). As
argued by the Examiner, “Kurita recognized an advantage to using the
exhaust of the combustor for two purposes, one to drive a compressor and
two to heat the incoming reactants to the fuel cell.” (Ans. 9). Contrary to
Appellants’ argument that there is no evidence to support the Examiner’s
position, Kurita discloses that heat of combustion exhaust gas is exchanged
by the heat exchanger to ensure stable operation of the fuel cell. (FF 4).
Appellants have provided no support for their assertion that “maintaining”
the temperature in the gas pipes at the inlet of the fuel cell does not involve
any heating of the reactants received by the fuel cell stack. Nor have
Appellants provided any evidence that after providing energy to drive the
turbine, the combustion exhaust gas would not have enough heat to raise the
temperature of the reactant gas to any extent. Therefore, Appellants’
arguments are not persuasive.
Claim 45
Regarding claim 45, Appellants argue that Kurita’s diagrams are
insufficient to show that fuel and oxidant enter through the same wall of the
combustion chamber as recited in claim 45. (App. Br. 14). However,
Kurita’ block diagram depicts air line 61 and reformed gas line 62 entering
the combustor from inlets located in the same wall of the combustor. (FF 2
and 3). Appellants have failed to provide any persuasive evidence that one
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of ordinary skill would interpret Kurita’s Figure 1 to disclose a different
configuration for the fuel and oxidant inlets. Further, Appellants have failed
to demonstrate any criticality or unexpected results by locating the fuel and
oxidant inlets in the same wall of the catalytic combustor. Therefore,
Appellants’ arguments are not persuasive.

Rejection of claim 4, 5, 37, and 51-53 over Kurita, Griesmeier, and
further in view of Dibble.
The Examiner found that Kurita in view of Griesmeier does not
disclose a heating element for heating the catalytic combustor as recited in
claim 4. (Ans. 4). The Examiner found that Dibble discloses a catalytic
combustor that is preheated by a resistive heating element. (Ans. 4). The
Examiner determined that it would have been obvious to one of ordinary
skill in the art to include a resistance heater in the fuel cell of Kurita as
modified by Griesmeier in order to more quickly preheat the combustor to
optimal operating temperatures. (Ans. 4).
Appellants contend that Dibble does not disclose or suggest heating
elements for heating both the catalytic combustor and the reactants in the
catalytic combustor as recited in claim 4. (App. Br. 16).

ISSUE
The issue is:
Have Appellants shown that the Examiner reversibly erred in
determining that Dibble discloses a heating element as recited in claim 4?

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ADDITIONAL FINDINGS OF FACT
5. Dibble discloses that the catalytic combustor is preheated by being
supplied with a preheat air/fuel mixture. (Abstract).
6. Dibble discloses conventional techniques for catalytic combustors
including “electrical resistance heating of the combustor air” using
electrical energy from batteries. (Col. 2, ll. 39-43).
ANALYSIS
We confine our discussion to appealed claim 4, which contains claim
limitations representative of the arguments made by Appellants.
We agree with the Examiner that claim 4 does not limit the location of
the heating element and that Dibble discloses heating both the catalytic
combustor and the reactants in the catalytic combustor. (Ans. 9).
Specifically, the heating element in Dibble preheats the air/fuel mixture,
which in turn heats the catalytic combustor. (Ans. 9; FF 5 and 6).
Therefore, the catalytic combustor and reactants in the catalytic combustor
are heated as required by the claim. Thus, we are not persuaded by
Appellants’ arguments that Dibble’s heating element does not teach or
suggest heating both the catalytic combustor and the reactants that are in that
catalytic combustor.

Rejection of claim 41 over Kurita, Griesmeier, and further in view of
Nikkanen.
The Examiner also found that Kurita in view of Griesmeier does not
teach a mixer connected to a heat exchanger as recited in claim 41. (Ans. 7).
The Examiner found that Nikkanen disclose a lobed mixer located at the
exhaust of the heat exchanger. (Id.). The Examiner found that Kurita,
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Griesmeier and Nikkanen “are analogous art because they are from the same
problem solving area of cooling exhaust gases before venting to the
atmosphere and at the same time heating inlet gases.” (Id.). The Examiner
determined that it would have been obvious to include a mixer at the exhaust
of the heat exchanger of Kurita “in order to properly cool the exhaust gases
before venting them to the atmosphere as well as preheating the incoming
gases at the same time.” (Id.).
Appellants argue that Nikkanen discloses a heat exchanger system for
a gas turbine engine, which has nothing to do with fuel cells, and the
Examiner has provided no explicit reasoning why Nikkanen would have
been combined with Griesmeier. (App. Br. 17-18).

ISSUE
The issue is:
Have Appellants shown that the Examiner reversibly erred in
determining that it would have been obvious to add the mixer of Nikkanen to
the fuel cell of Kurita in view of Griesmeier?

ADDITIONAL FINDINGS OF FACT
7. Nikkanen discloses a lobed mixer at the exhaust of a heat
exchanger in a gas turbine engine, where the mixer promotes
mixing of heated exhaust gases with cooler working medium gases
to ensure energy from the gases enters the working medium flow
path. (Col. 3, ll. 40-58, col. 10, ll. 3-34).

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ADDITIONAL PRINCIPLES OF LAW
In KSR, the Supreme Court explained, “[w]hen a work is available in
one field of endeavor, design incentives and other market forces can prompt
variations of it, either in the same field or a different one. If a person of
ordinary skill can implement a predictable variation, §103 likely bars its
patentability.” KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007).

ANALYSIS
We are not persuaded by Appellants’ contention that the Examiner has
failed to provide a sufficient reason to employ the teachings of Nikkanen in
gas turbine engines to a catalytic burner such as taught by Griesmeier.
Appellants have not identified any error in the Examiner’s determination
that Kurita, Griesmeier, and Nikkanen are analogous art because “they are
from the same problem solving area of cooling exhaust gases before venting
to the atmosphere and at the same time heating inlet gases.” (Ans. 7). Nor
have Appellants addressed, much less identified error in, the Examiner’s
rationale for combining Nikkanen with Kurita in view of Griesmeier
discussed supra.

CONCLUSION
Appellants have failed to demonstrate that the Examiner reversibly
erred in determining that Kurita discloses a heat exchanger that increases the
temperature of reactants as the reactants are received by the fuel cell stack.
Appellants have failed to demonstrate that the Examiner reversibly
erred in determining that Kurita discloses that fuel and oxidant enter the
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catalytic combustor through inlets located in the same wall of the catalytic
combustor.
Appellants have failed to demonstrate that the Examiner reversibly
erred in determining that Dibble discloses a heating element as recited in
claim 4.
Appellants have failed to demonstrate that the Examiner reversibly
erred in determining that it would have been obvious to add the mixer of
Nikkanen to the fuel cell of Kurita in view of Griesmeier.

ORDER
We affirm the Examiner’s decision rejecting claims 1-8, 36, 37, 39-
41, 45, and 47-56 under 35 U.S.C. § 103(a). Specifically we affirm the
Examiner’s decision rejecting: (1) claims 1-3, 45, and 47 as being
unpatentable over Kurita in view of Griesmeier; (2) claims 4, 5, 37, and 51-
53 as being unpatentable over Kurita in view of Griesmeier, and further in
view of Dibble; (3) claims 6-8, 48, and 49 as being unpatentable over Kurita
in view of Griesmeier, and further in view of Kelly; (4) claims 36 and 50 as
being unpatentable over Kurita in view of Griesmeier, and further in view of
Yabuuchi; (5) claims 39 and 55 as being unpatentable over Kurita in view of
Griesmeier, Dibble, and further in view of DeFreitas; (6) claims 40 and 54 as
being unpatentable over Kurita in view of Griesmeier, Dibble, and further in
view of Baker; and (7) claims 41 and 56 as being unpatentable over Kurita
in view of Griesmeier, and further in view of Nikkanen.

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)(v).
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Appeal 2009-001249
Application 10/282,358

AFFIRMED

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HEWLETT PACKARD COMPANY
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