       NOTE: This disposition is nonprecedential.

  United States Court of Appeals
      for the Federal Circuit
              __________________________

            (Reexamination No. 95/001,168)
                FLUOR TEC, CORP.,
                    Appellant,
                           v.
        DAVID J. KAPPOS, DIRECTOR,
  UNITED STATES PATENT AND TRADEMARK
                  OFFICE,
                  Appellee,
                         AND

          LUMMUS TECHNOLOGY, INC.,
                  Appellee.
              __________________________

                      2012-1295
              __________________________

    Appeal from the United States Patent and Trademark
Office, Board of Patent Appeals and Interferences.
                __________________________

             Decided: December 11, 2012
              __________________________

    ROBERT D. FISH, Fish & Associates, PC, of Irvine,
California, argued for appellant. With him on the brief
was MEI TSANG.
FLUOR TEC   v. KAPPOS                                    2




     RAYMOND T. CHEN, Solicitor, United States Patent
and Trademark Office, of Arlington, Virginia, argued for
appellee, United States Patent and Trademark Office.
With him on the brief were AMY J. NELSON and KRISTI
L.R. SAWERT, Associate Solicitors.
   JEFFREY S. BERGMAN, Osha Liang LLP, of Houston,
Texas, argued for appellee, Lummus Technology, Inc.
               __________________________

 Before LOURIE, BRYSON, and WALLACH, Circuit Judges.
LOURIE, Circuit Judge.
    Fluor Tec, Corp. (“Fluor”) appeals from the decision of
the Board of Patent Appeals and Interferences (the
“Board”) in an inter partes reexamination affirming the
Examiner’s decision not to reject claims 1–9, 11, 13, 25–
29, 31, 33, 37–47, 55, 56, and 58 of U.S. Patent 6,712,880
(the “’880 patent”) owned by Lummus Technology, Inc.
(“Lummus”). See Fluor Tec, Corp. v. Patent of Lummus
Tech. Inc., No. 2011-013099 (B.P.A.I. Dec. 15, 2011)
(“Board Decision”). Because substantial evidence sup-
ports the Board’s conclusion that the claimed invention
would not have been obvious in view of the cited prior art,
we affirm.
                        BACKGROUND
    This appeal arises from an inter partes reexamination
of the ’880 patent in the U.S. Patent and Trademark
Office (the “PTO”), assigned Patent Reexamination Con-
trol Number 95/001,168, which was initiated by third
party requester Fluor under 35 U.S.C. § 311 and 37
C.F.R. § 1.913.
   The ’880 patent is directed to cryogenic processes for
separating   multi-component     gaseous    hydrocarbon
3                                       FLUOR TEC   v. KAPPOS


streams to recover both gaseous and liquid compounds
using a high pressure absorber. ’880 patent col.1 ll.10–15.
The abridged claim 1 recited below, as amended during
the reexamination proceeding, is representative of the
claimed elements in dispute:
    1. A process for separating a heavy key compo-
    nent from an inlet gas stream containing a mix-
    ture of methane, C2 compounds, C3 compounds,
    and heavier compounds, comprising the following
    steps:
    (a) at least partially condensing and separat-
        ing the inlet gas into a first liquid stream
        and a first vapor stream;
    (b) expanding at least a portion of the first
        liquid stream, at least a portion of which
        is then designated as a first fractionation
        feed stream;
    (c) supplying a fractionation column the first
        fractionation feed stream and a second
        fractionation feed stream, the fractiona-
        tion column produces a fractionation over-
        head vapor stream and a fractionation
        bottom stream;
    (d) expanding at least a portion of the first
        vapor stream, such expanded portion then
        designated as an expanded vapor stream;
    (e) supplying an absorber the expanded vapor
        stream and an absorber feed stream, the
        absorber produces an absorber overhead
        stream and an absorber bottom stream,
        the absorber having an absorber pressure
        that is substantially greater than and at a
FLUOR TEC   v. KAPPOS                                      4


        predetermined differential pressure from
        a fractionation column pressure; . . .
J.A. 325–326 (bracketing and underlining showing
changes relative to the original patent claim omitted).
    Figure 1, reproduced below, depicts a flow diagram of
a separation process according to the ’880 patent:




’880 patent fig. 1.
     Relevant to the issues argued in this appeal, Lum-
mus’s separation apparatus is a two-column system that
includes an absorber column [18] and a downstream
fractionation column [22], wherein the absorber column is
operated at a pressure substantially greater than the
fractionation column. ’880 patent col.6 ll.52–60, col.3
ll.48–54. Inlet gas [40] is first cooled or condensed in heat
exchanger [12] and separated in separator [14] into first
5                                       FLUOR TEC   v. KAPPOS


liquid stream [44] and first vapor stream [42]. Id. col.7
ll.18–27. The first liquid stream [44] is expanded in
expander [24], heated in exchanger [12], and supplied to a
middle tray of fractionation column [22] as first fractiona-
tion feed stream [58]. Id. col.7 ll.31–35. A portion of first
liquid stream [44] may be fed to overhead exchanger [20],
as well as exchanger [12], before being supplied to frac-
tionation column [22]. Id. col.8 ll.5–11. The first vapor
stream [42] is expanded in turboexpander [16] to the
operating pressure of absorber [18]. Id. col.7 ll.29–31.
The expanded first vapor stream [42a] is then fed into the
lower end of absorber [18]. Id. col.7 ll.34–36. In the
absorber, heavier compounds in the vapor stream are
absorbed by the falling liquid stream to produce absorber
bottom stream [45], and lighter compounds rise to the top
of the column to produce absorber overhead stream [46].
Id. col.7 ll.50–59. Absorber bottom stream [45] is cooled
(condensed) in exchangers [20] and [12], and fed into the
middle of fractionation column [22] as second fractiona-
tion feed stream [48]. Id. col.7 ll.60–62, col.8 ll.17–21.
    In requesting reexamination, Fluor relied on Interna-
tional Patent Publication Number WO 02/14763 of Mak
(the “Mak application”) as evidence of unpatentability.
The Mak application discloses gas processing methods
and configurations suitable for the recovery of propane or
ethane that include an absorber and a fractionation
column where the absorber is operated at a pressure
higher than the fractionation column. Mak Appl. 2–3.
The Mak application discloses two different configura-
tions for gas separation, which depend on the pressure of
the feed gas. One configuration, designed for use with
low-pressure feed gas, does not involve expanding the first
vapor stream, and is depicted in a flow diagram in Figure
5, reproduced below:
FLUOR TEC   v. KAPPOS                                   6




Mak Appl. fig. 5.
    In this low-pressure design, the feed gas [1] is sepa-
rated in separator [101] into a liquid portion [5] and a
gaseous portion [2]. Id. at 8. The liquid portion [5] is
expanded in Joules-Thompson valve [115] and fed directly
into the fractionation column [106], and the gaseous
portion [2] is cooled in heat exchanger [100] and fed into
absorber [103] without expansion in a turboexpander. Id.
The absorber overhead stream [9] is heated in exchanger
[100] and fed into the gas pipeline without recompression,
and the absorber bottom stream [7] is expanded in Joules-
Thompson valve [104], which reduces the pressure and
temperature, then heated in exchanger [105] and fed into
the top of fractionation column [106]. Id.
    The other configuration disclosed in the Mak applica-
tion, designed for use with high-pressure feed gas, is
depicted in a flow diagram in Figure 2, reproduced below:
7                                      FLUOR TEC   v. KAPPOS




Mak Appl. fig. 2.
    In this high-pressure design, the feed gas [1], [2] is
cooled in heat exchanger [100] and separated in separator
[101] into a liquid portion [5] that is fed into the upper
end of absorber [103], and a gaseous portion [4] that is
expanded in turboexpander [102] and fed into a lower
section of absorber [103]. Id. at 6. The absorber bottom
stream [7] is expanded in Joules-Thompson valve [104],
which lowers the pressure and significantly cools the
stream, then heated in exchangers [100] and [105] and
then fed into the top of fractionation column [106]. Id.
    During reexamination, the Examiner rejected some of
the patent claims as anticipated under 35 U.S.C. § 102(e)
by the Mak application, and some of the claims as obvious
under 35 U.S.C. § 103 in view of the Mak application.
Thereafter, Lummus amended the independent claims to
incorporate limitations from the dependent claims.
Specifically, claim 1 was amended as excerpted above.
Following the amendment, the Examiner withdrew the
rejections of the claims in view of the Mak application. In
particular, the Examiner found that the vapor stream in
Mak’s low-pressure configuration (i.e., stream [2], [6] in
Figure 5) is not expanded prior to entering the absorber,
FLUOR TEC   v. KAPPOS                                    8


as required by the claims. Right of Appeal Notice dated
Jan. 20, 2011 in Control No. 95/001,168, 20–21. Further,
the Examiner noted that, according to Lummus’s
amended claims, the first fractionation feed stream in the
’880 patent has the same chemical composition as the first
liquid stream, which is merely renamed after being
warmed in the heat exchangers en route to the fractiona-
tion column. Id. at 14–15. In contrast, the first liquid
stream in Mak’s high-pressure configuration (i.e., stream
[5] in Figure 2) is initially fed to the absorber, where it
undergoes chemical processing, and it is the chemically
altered absorber bottom stream that is fed into the frac-
tionation column as the first fractionation feed stream.
Id. at 15–16.
     Fluor then appealed to the Board under 35 U.S.C. §
134(c). The Board affirmed the Examiner’s finding that
the Mak application failed to anticipate the claims, and
Fluor does not challenge that holding on appeal. See
Board Decision at 12. The Board, like the Examiner, also
found that it would not have been obvious to add an
expander to the low-pressure configuration taught by the
Mak application and depicted in Figure 5 because that
system was specifically designed and labeled not to in-
clude turboexpansion. Id. at 12–13. The Board also
concluded that the Examiner was correct in finding that
there was no motivation for a skilled artisan to modify the
high-pressure configuration taught by Mak and depicted
in Figure 2 by rerouting the liquid stream to the frac-
tionation column. Id. at 13. Accordingly, the Board
affirmed the Examiner’s decision not to reject the claims.
    Fluor timely appealed. We have jurisdiction pursuant
to 28 U.S.C. § 1295(a)(4)(A).
9                                       FLUOR TEC   v. KAPPOS


                        DISCUSSION
    A claim is invalid for obviousness if, to one of ordinary
skill in the pertinent art, “the differences between the
subject matter sought to be patented and the prior art are
such that the subject matter as a whole would have been
obvious at the time the invention was made.” 35 U.S.C.
§ 103(a) (2006); see also KSR Int’l Co. v. Teleflex Inc., 550
U.S. 398, 406–07 (2007). Obviousness is a legal conclu-
sion based on underlying factual findings. In re Kao, 639
F.3d 1057, 1065 (Fed. Cir. 2011). We review the Board’s
legal conclusions de novo and its factual determinations
for substantial evidence. In re Am. Acad. Sci. Tech. Ctr.,
367 F.3d 1359, 1363 (Fed. Cir. 2004). Substantial evi-
dence means “such relevant evidence as a reasonable
mind might accept as adequate to support a conclusion.”
Consol. Edison Co. v. Nat’l Labor Relations Bd., 305 U.S.
197, 229 (1938).
                             I.
    The claims of the ’880 patent require either “expand-
ing” or an “expansion means” for expanding at least a
portion of the first vapor stream, which the specification
discloses are to “be effectuated with a turbo-expander,
Joules-Thompson expansion valves, a liquid expander, a
gas or vapor expander or the like.” J.A. 325–326; ’880
patent col.6 ll.35–39. Fluor contends that the Board
incorrectly determined that it would not have been obvi-
ous to add an expander to the low-pressure configuration
depicted in Figure 5 of the Mak application. Fluor argues
that it would have been a mere design choice for a skilled
artisan to add an expander when utilizing Mak’s low-
pressure system with a high-pressure feed gas in order to
improve the efficiency of the absorber, since the need to
match the feed gas pressure with the absorber pressure
FLUOR TEC   v. KAPPOS                                       10


was well-known in the prior art.1 We disagree because
substantial evidence supports the Board’s factual findings
underlying its conclusion that the claims would not have
been obvious.
     The system depicted in Figure 5 of the Mak applica-
tion does not include expanding at least a portion of the
first vapor stream as required by the claims; rather, vapor
stream [2], [6] is fed into absorber [103] after cooling in
heat exchanger [100], but without passing through an
expander. Indeed, Mak’s low feed pressure configuration
specifically excludes an expander: Figure 5 is expressly
labeled as a “No Turboexpansion Design,” and the Mak
specification recites (i) that “[t]he gaseous portion of [2] is
cooled in a heat exchanger [100] and the cooled gaseous
portion [6] is then fed into absorber [103] without expan-
sion in a turboexpander,” Mak Appl. 8 (emphasis added);
(ii) that “Figure 5 is a . . . configuration for a gas process-
ing plant without turboexpander,” id. at 4 (emphasis

    1   To support its argument, Fluor relies, in part, on
U.S. Patent 4,657,571 issued to Gazzi (“Gazzi”), which is
cited in the background section of the ’880 patent, but is
not incorporated by reference into the patent specification
or part of the prosecution history of the reexamination
application. Fluor admits that Gazzi was never refer-
enced in arguments to the Examiner or the Board and
was not part of the administrative record considered by
the Board, but nevertheless contends that it was within
the knowledge of a person of ordinary skill in the art and
therefore the Board’s failure to consider it warrants
vacating and remanding the Board’s decision. Appellant
Reply. Br. 9. However, because 35 U.S.C. § 144 provides
that we “review the decision from which an appeal is
taken on the record before the [PTO],” Gazzi is not prop-
erly before us for consideration on appeal. In re Watts,
354 F.3d 1362, 1367 (Fed. Cir. 2004) (“[R]eview of the
Board’s decision is confined to the ‘four corners’ of that
record.”).
11                                      FLUOR TEC   v. KAPPOS


added); and (iii) that “the feed gas is fed into the absorber
without passing through a turboexpander,” id. at 8 (em-
phasis added).
    We agree with the Board’s determination that it
would not have been obvious to modify Mak’s disclosure to
add an expander. See DePuy Spine, Inc. v. Medtronic
Sofamor Danek, Inc., 567 F.3d 1314, 1326 (Fed. Cir. 2009)
(“An inference of nonobviousness is especially strong
where the prior art’s teachings undermine the very reason
being proffered as to why a person of ordinary skill would
have combined the known elements.”). The Mak applica-
tion discloses two different configurations, one designed
for high-pressure feed gas and one designed for low-
pressure feed gas, and that Mak specifically discusses the
advantages of the “no turboexpander design” for low-
pressure feed gas. See Mak Appl. 8–9. In Mak’s system,
depicted in Figure 5, the gaseous portion is cooled in a
heat exchanger before being fed into the absorber, but if
high-pressure feed gas could be accommodated simply by
adding an expander to the low-pressure configuration,
then there would be no need for the separate high-
pressure configuration. See In re Gal, 980 F.2d 717, 719
(Fed. Cir. 1992) (holding that different structure to
achieve different purpose was not an obvious design
choice). Adding an expander to Mak’s low-pressure
configuration is not simply a design choice that one would
employ.
    Moreover, a skilled artisan desiring to utilize a high-
pressure feed gas would have been directed to follow the
alternative systems disclosed in the Mak application that
are specifically designed to accommodate a high-pressure
feed gas, rather than attempt to modify Mak’s low-
pressure configuration. See In re Gurley, 27 F.3d 551, 553
(Fed. Cir. 1994) (a reference teaches away “when a person
of ordinary skill, upon reading the reference . . . would be
FLUOR TEC   v. KAPPOS                                     12


led in a direction divergent from the path that was taken
by the applicant”). Accordingly, viewing the teachings of
the Mak application as a whole, a skilled artisan would
not have been motivated to add an expander to the low-
pressure configuration depicted in Figure 5 to arrive at
the claimed invention. Because the Board’s fact-finding is
supported by substantial evidence, we affirm its conclu-
sion of nonobviousness. In re Jolley, 308 F.3d 1317, 1320
(Fed. Cir. 2002).
                             II.
    The claims of the ’880 patent also require that the
inlet gas is separated into a first liquid stream and a first
vapor stream, and that at least a portion of the first liquid
stream is designated as a first fractionation feed stream,
which is supplied to a fractionation column. J.A. 325–
326.
     Fluor contends that the Board incorrectly determined
that it would not have been obvious to modify the high-
pressure configuration depicted in Figure 2 of the Mak
application by rerouting the first liquid stream [5]—
produced upon initial separation of feed gas [1], [2] in
separator [101]—to the fractionation column [106] instead
of to absorber [103] as disclosed. Fluor argues that a
skilled artisan would have routed the liquid phase differ-
ently depending on the composition of the feed gas itself,
i.e., whether it was rich or lean.2 Fluor asserts that it
would have been obvious to reroute the liquid phase to the

    2    A lean gas stream is one that contains a higher
proportion of lighter hydrocarbons, such as methane (C1)
and ethane (C2), and a lower percentage of heavier hydro-
carbons, such as propane (C3) and butane (C4). In con-
trast, a rich gas stream is one that contains a lower
proportion of lighter hydrocarbons and a higher propor-
tion of heavier hydrocarbon components.
13                                     FLUOR TEC   v. KAPPOS


fractionation column as claimed, rather than to the ab-
sorber column as described in Mak’s high-pressure con-
figuration, when the feed gas is rich because that would
provide a more efficient separation in the system depicted
in Figure 2, which is specifically designed for lean feed
streams. We again disagree because substantial evidence
supports the Board’s factual findings underlying its
conclusion that the claims would not have been obvious.
    First, in the system depicted in Figure 2 of the Mak
application, the liquid stream [5] is fed into the absorber
[103] and undergoes chemical processing in the absorber,
by interaction with gas stream [6] and reflux stream [19],
to produce a liquid absorber bottom stream [7]. Mak
Appl. 6, fig. 2. This chemically altered absorber bottom
stream is subsequently expanded in Joules-Thompson
valve [104], heated in exchangers [100] and [105], and
then fed into fractionation column [106]. Id. In contrast,
Lummus’s claims require that the expanded liquid stream
be supplied directly to the fractionation column as a first
fractionation feed stream without further chemical proc-
essing. The ’880 patent specification discloses that, with
reference to Figure 1, after the feed gas is separated in
separator [12], “[t]he first liquid stream [44] is expanded
in expander [24] and then supplied to front end exchanger
[12] and warmed . . . then supplied to a mid-column feed
tray of fractionation column [22] as a first fractionation
feed stream [58].” ’880 patent col.7 ll.31–35.
     Second, Lummus’s claims at issue here are not limited
only to a rich feed gas, but encompass any hydrocarbon
stream. See, e.g., claim 1 (“inlet gas stream containing a
mixture of methane, C2 compounds, C3 compounds, and
heavier compounds”); see also ’880 patent abstract, col.1
ll.11–15, col.5 l.65–col.6 l.16. Moreover, neither the
claimed invention nor the Mak application discloses or
suggests that the mixture of hydrocarbons in the feed gas
FLUOR TEC   v. KAPPOS                                   14


should have a direct bearing on the choice of which proc-
ess should be employed for separation; on the contrary,
the disclosure in Mak emphasizes that the choice of
configuration should depend on the pressure of the feed
gas, not the composition. Mak Appl. 3, 6, 8, 10–11.
    Finally, Fluor has provided no evidence or rationale to
support its proposition that a skilled artisan would have
been motivated to substantially modify Mak’s high-
pressure configuration by rerouting the first liquid stream
depending on the composition of the feed gas. KSR, 550
U.S. at 418 (requiring “some articulated reasoning with
some rational underpinning to support the legal conclu-
sion of obviousness” (quoting In re Kahn, 441 F.3d 977,
988 (Fed. Cir. 2006))); see also Mintz v. Dietz & Watson,
Inc., 679 F.3d 1372, 1377 (Fed. Cir. 2012) (obviousness
determination improper where “little more than an invo-
cation of the words ‘common sense’ (without any record
support showing that this knowledge would reside in the
ordinarily skilled artisan)”). Therefore, again viewing the
teachings of the Mak application as a whole, a skilled
artisan would not have been motivated to modify the
high-pressure configuration depicted in Figure 2 by
rerouting the liquid stream to arrive at the claimed
invention. Because the Board’s fact-finding is supported
by substantial evidence, we affirm its conclusion of
nonobviousness. Jolley, 308 F.3d at 1320.
                        CONCLUSION
    We have considered Fluor’s remaining arguments and
find them unpersuasive. The Board’s judgment is af-
firmed.
                        AFFIRMED
