Ex Parte Fauroux

Board of Patent Appeals and Interferences

Jun 1, 2010

10572668 (B.P.A.I. Jun. 1, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte DANIELE FAUROUX
__________

Appeal 2009-013489
Application 10/572,668
Technology Center 1600
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Decided: June 1, 2010
__________

Before TONI R. SCHEINER, LORA M. GREEN, and
JEFFREY N. FREDMAN, Administrative Patent Judges.

FREDMAN, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to methods
for producing carbon monoxide by cryogenic distillation. We have
jurisdiction under 35 U.S.C. § 6(b). We affirm.

Appeal 2009-013489
Application 10/572,668

Statement of the Case
The Claims
Claims 9-12 are on appeal. Claim 9 is representative and reads as
follows:
9. A method for producing carbon monoxide by
cryogenic distillation comprising the following steps:
a) a gas mixture containing carbon monoxide,
hydrogen and nitrogen is cooled and partially condensed to
produce a cooled and partially condensed gas mixture;
b) the cooled and partially condensed gas mixture is
separated to produce a hydrogen-enriched gas and a carbon
monoxide-enriched liquid;
c) a stream of the carbon monoxide-enriched liquid is
sent to a stripping column to produce hydrogen-free liquid
carbon monoxide and hydrogen-enriched carbon monoxide
gas;
d) a stream of the hydrogen-free carbon monoxide is
sent to a first intermediate level of a distillation column;
e) a liquid stream, richer in methane compared to the
stream feeding to the distillation column, is withdrawn from
the bottom of the distillation column;
f) a carbon monoxide-rich stream is withdrawn from a
second intermediate point, the second intermediate point
being above the first intermediate point; and
g) a stream, enriched with nitrogen and optionally
hydrogen compared to the stream feeding to the distillation
column, is withdrawn from the top of the distillation
column.

The prior art
The Examiner relies on the following prior art reference to show
unpatentability:
Fabian DE 19541339 May 7, 1997

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The issue
The Examiner rejected claims 9-12 under 35 U.S.C. § 103(a) as
obvious over Fabian (Ans. 3-4).
The Examiner finds that the “difference between Fabian and the
claimed invention is that the instant claims only utilize one rectification
column, whereas the Fabian's process utilizes more than one rectification
column” (id. at 4). The Examiner concludes that “it is well within the
purview of one ordinary skill in the art to modify the number of rectification
column, in order to reduce the capital costs and still obtaining high purity of
carbon monoxide” (id.).
Appellant argues that Fabian “teaches removing the nitrogen-rich
fraction at an intermediate step to the removal of the carbon monoxide”
(App. Br. 11). Appellant argues that this is “in contradistinction with the
requirement of claim 9 of the present invention, which requires the carbon
monoxide rich stream to be removed at an intermediate point and the
nitrogen enriched stream to be removed at the top of the distillation column”
(id.). Appellant also argues that “[o]ne skilled in this art would recognize
that it would be very difficult, possibly impossible, to collapse these two
rectification columns, with all the intermediate exchanges of heat, into a
single column and retain the same product purity” (id.).
In view of these conflicting positions, we frame the obviousness issue
before us as follows:
Does the evidence of record support the Examiner’s conclusion that
claim 9 would have been obvious to the ordinary artisan over the teachings
of Fabian?
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Application 10/572,668

Findings of Fact
1. Fabian teaches:
A method for obtaining carbon monoxide from a nitrogen-
contaminated gas stream that essentially contains hydrogen,
carbon monoxide and methane, in which
a) the gas stream is cooled and partially condensed,
b) the first hydrogen-rich fraction that accumulates in
the partial condensation is removed,
c) the carbon monoxide-rich condensate, which
contains methane and nitrogen and is obtained in the partial
condensation is sent to a hydrogen stripping column,
d) in said column, separation into a second hydrogen-
rich fraction and another carbon monoxide-rich fraction
takes place, and
e) said carbon monoxide-rich fraction containing
methane and nitrogen is separated at low temperature into a
highly pure carbon monoxide fraction and a fraction
essentially containing methane and nitrogen
characterized by the fact that
f) the carbon monoxide-rich fraction that contains
methane and nitrogen coming from the hydrogen stripping
column is sent to a first rectification column,
g) in said rectification column, a separation into a
nitrogen-rich and a carbon monoxide-rich fraction
containing methane takes place,
h) the nitrogen-rich fraction is withdrawn,
i) the carbon monoxide-rich fraction containing
methane is sent to a second rectification column, and
k) in said rectification column, a separation into the
highly pure carbon monoxide product fraction and into a
fraction essentially containing methane takes place.

(Fabian Trans. 16-17, Claim 1.)
2. Fabian teaches, “[v]arious possibilities for solving the problems
that are caused by nitrogen are known” (Fabian trans. 3).
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Application 10/572,668

3. Fabian teaches that while “integration of a nitrogen/carbon
monoxide separation. . . involves considerable additional costs . . .
Compared to an otherwise necessary nitrogen separation . . . this solution
nevertheless is in many cases the more profitable and simpler, if the nitrogen
content in the carbon monoxide product must be limited” (Fabian trans. 4).
4. The Examiner finds that “‘comprising’ does not limit the
number of rectification [columns] to only one column” (Ans. 5).
5. The Examiner “notes the differences with respect to [the]
location of [the] withdrawing carbon monoxide-rich stream and carbon
dioxide. However theses [sic] differences are not patentably distinct in the
absence of unexpected results” (Ans. 4).
Principles of Law
“The combination of familiar elements according to known methods
is likely to be obvious when it does no more than yield predictable results.”
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007). “If a person of
ordinary skill can implement a predictable variation, § 103 likely bars its
patentability.” Id. at 417. Moreover, an “[e]xpress suggestion to substitute
one equivalent for another need not be present to render such substitution
obvious.” In re Fout, 675 F.2d 297, 301 (CCPA 1982).
As noted by the Court in KSR, “[a] person of ordinary skill is also a
person of ordinary creativity, not an automaton.” 550 U.S. at 421.
Analysis
Appellant argues that Fabian “teaches removing the nitrogen-rich
fraction at an intermediate step to the removal of the carbon monoxide”
(App. Br. 11). Appellant argues that this is “in contradistinction with the
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Application 10/572,668

requirement of claim 9 of the present invention, which requires the carbon
monoxide rich stream to be removed at an intermediate point and the
nitrogen enriched stream to be removed at the top of the distillation column”
(App. Br. 11). Appellant argues that the “skilled artisan would find that not
only does Fabin [sic Fabian] ‘339 not render the instant invention obvious,
but actually teaches away from the instant invention” (id.).
The Examiner “notes the differences with respect to location of
withdrawing carbon monoxide-rich stream and carbon dioxide. However
theses differences are not patentably distinct in the absence of unexpected
results” (Ans. 4).
We find that the Examiner has the better position. As noted by the
Court in KSR, “[a] person of ordinary skill is also a person of ordinary
creativity, not an automaton.” 550 U.S. at 421. Here, as the Examiner finds
(FF 5), the ordinary artisan would reasonably understand that modifying the
location at which the carbon monoxide stream is withdrawn represents a
tradeoff of purity for cost and effort. As Fabian teaches, “[v]arious
possibilities for solving the problems that are caused by nitrogen are known”
(Fabian trans. 3; FF 2). Fabian teaches that while “integration of a
nitrogen/carbon monoxide separation. . . involves considerable additional
costs . . . Compared to an otherwise necessary nitrogen separation . . . this
solution nevertheless is in many cases the more profitable and simpler, if the
nitrogen content in the carbon monoxide product must be limited” (Fabian
trans. 4; FF 3).
Appellant does not provide any evidence that selection of the carbon
monoxide removal point is unpredictable or results in an unexpected result.
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Application 10/572,668

Selection of the optimal level of carbon monoxide purification in Fabian’s
rectification columns is merely a “predictable use of prior art elements
according to their established functions.” KSR, 550 U.S. at 417.
We also are not persuaded that Fabian teaches away from the claimed
method in teaching a particular mode of carbon monoxide purification (FF
1-3). Like our appellate reviewing court, “[w]e will not read into a reference
a teaching away from a process where no such language exists.” DyStar
Textilfarben GmbH & Co. Deutschland KG v. C.H. Patrick Co., 464 F.3d
1356, 1364 (Fed. Cir. 2006).
Appellant also argues that “[o]ne skilled in this art would recognize
that it would be very difficult, possibly impossible, to collapse these two
rectification columns, with all the intermediate exchanges of heat, into a
single column and retain the same product purity” (App. Br. 11).
However, as the Examiner correctly notes, Appellant’s Claim 9 uses
the open transitional phrase “comprising” and contains no language which
excludes the use of multiple rectification columns (see Claim 9). See
Genentech, Inc. v. Chiron Corp., 112 F.3d 495, 501 (Fed. Cir. 1997)
(“Comprising’ is a term of art used in claim language which means that the
named elements are essential, but other elements may be added and still
form a construct within the scope of the claim.”)
Appellant argues that it “is well known to the skilled artisan that a
multiple distillation column system, such as disclosed by Fabian, will
produce streams of higher purity products than a single distillation column
with an intermediate withdrawal, such as in the instant application” (Reply
Br. 2). Appellant argues that “in the instant application, the carbon
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monoxide-rich stream 29 is indicated to have a purity of 98.5% CO . . . In
contrast, the equivalent highly pure carbon monoxide stream 16 in Fabian, is
indicated to have a purity of 99.9% CO” (Reply Br. 2).
In our opinion, this argument sums up the Examiner’s obviousness
case. Appellant acknowledges that the skilled artisan would appreciate that
increasing the number of distillation columns would predictably result in
increased purity of carbon monoxide (id.) with the obvious corollary that
reducing the number of distillation columns would reduce the purity of
carbon monoxide. Appellant points to evidence that Fabian’s multiple
columns result in a purer product than that of the claimed system (id.).
We conclude that it would have been predictable, and consequently
obvious, to reduce the number of columns in order to reduce the cost and
complexity of the carbon monoxide purification process (see, e.g., FF 2-5).
The skilled artisan would have recognized the tradeoff between cost and the
level of carbon monoxide purification as expressly recognized by Fabian
who teaches that while “[i]ntegration of a nitrogen/carbon monoxide
separation. . . involves considerable additional costs . . . Compared to an
otherwise necessary nitrogen separation . . . this solution nevertheless is in
many cases the more profitable and simpler, if the nitrogen content in the
carbon monoxide product must be limited” (Fabian trans. 4; FF 3).
Conclusion of Law
The evidence of record supports the Examiner’s conclusion that claim
9 would have been obvious to the ordinary artisan over the teachings of
Fabian.
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Application 10/572,668

SUMMARY
In summary, we affirm the rejection of claim 9 under 35 U.S.C. §
103(a) as obvious over Fabian. Pursuant to 37 C.F.R. §
41.37(c)(1)(vii)(2006), we also affirm the rejection of claims 10-12 as these
claims were not argued separately.
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)(2006).

AFFIRMED

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