Ex Parte Price

Patent Trial and Appeal Board

Mar 28, 2018

12799061 (P.T.A.B. Mar. 28, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
121799,061 04/16/2010
23589 7590 03/30/2018
Hovey Williams LLP
10801 Mastin Blvd., Suite 1000
Overland Park, KS 66210
FIRST NAMED INVENTOR
Brian C. Price
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
ATTORNEY DOCKET NO. CONFIRMATION NO.
43886 3059
EXAMINER
RAYMOND, KEITH MICHAEL
ART UNIT PAPER NUMBER
3744
NOTIFICATION DATE DELIVERY MODE
03/30/2018 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address( es):
amalik@hoveywilliams.com
uspatents@hoveywilliams.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte BRIAN C. PRICE
Appeal2016-006864
Application 12/799,061
Technology Center 3700
Before JENNIFER D. BAHR, MICHAEL L. WOODS, and
FREDERICK C. LANEY, Administrative Patent Judges.
LANEY, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Brian C. Price (Appellant) 1 appeals under 35 U.S.C. § 134(a) from the
Examiner's decision (mailed June 16, 2015, hereinafter "Final Act.")
rejecting claims 1--4 and 12-15 under 35 U.S.C. § 103(a) as unpatentable
over Phade (US 4,878,932, iss. Nov. 7, 1989), Swenson (US 4,033,735, iss.
July 5, 1977), and Hahn (US 7 ,234,322 B2, iss. June 26, 2007). 2 We have
jurisdiction over this appeal under 35 U.S.C. § 6(b).
1 Black & Veatch Holding Company is identified as the real parties in
interest in Appellant's Appeal Brief (filed Dec. 16, 2015, hereinafter
"Appeal Br."), at page 4.
2 Claims 5-11 have been canceled. Amendment 3 (filed June 12, 2014).
Appeal 2016-006864
Application 12/799,061
We REVERSE.
INVENTION
Appellant's invention relates to "a mixed single refrigerant process for
separating a nitrogen gas stream from a natural gas stream containing
nitrogen to produce a nitrogen gas stream and a liquefied natural gas
stream." Spec. i-f 1. There are two independent claims, 1 and 13, pending in
this appeal. Claim 1, reproduced below, is illustrative of the invention the
Specification discloses.
1. A process for producing liquefied natural gas from
a nitrogen-containing natural gas stream, the process comprising:
a) cooling a stream of mixed refrigerant in a first heat
exchanger of a single closed-loop mixed refrigerant system to
provide a cooled mixed refrigerant stream;
b) expanding at least a portion of the cooled mixed
refrigerant stream to produce an expanded mixed refrigerant
stream;
c) cooling and at least partially condensing the natural gas
stream in a first heat exchange passageway via indirect heat
exchange with the expanded mixed refrigerant stream in the first
heat exchanger to produce a cooled natural gas stream;
d) dividing the cooled natural gas stream withdrawn from
the first heat exchange passageway into a first portion and a
second portion;
e) introducing the first portion into a lower inlet of a first
vapor-liquid separator;
f) subsequent to said dividing, subcooling the second
portion in the first heat exchanger to provide a subcooled liquid
portion, wherein said subcooling is carried out in a second heat
exchange passageway via indirect heat exchange with said
expanded mixed refrigerant;
g) subsequent to said subcooling, introducing the
subcooled liquid portion into an upper inlet of the first vapor-
liquid separator, wherein the upper inlet of the first vapor-liquid
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Application 12/799,061
separator is located at a higher vertical elevation than the lower
inlet;
h) withdrawing a methane rich liquid bottoms stream and
a first nitrogen rich vapor overhead stream from the first vapor-
liquid separator;
i) further cooling the methane rich liquid bottoms stream
in the first heat exchanger in a third heat exchange passageway
to provide a first liquid natural gas stream;
j) introducing at least a portion of the first liquid natural
gas stream into an inlet of a nitrogen stripping column;
k) introducing at least a portion of the first nitrogen rich
vapor overhead stream into another inlet of the nitrogen stripping
column;
1) withdrawing a stream of nitrogen-depleted liquefied
natural gas (LNG) from a lower portion of the nitrogen stripping
column, wherein the LNG comprises less than 3 volume percent
nitrogen;
m) recovering an overhead nitrogen rich vapor stream
from a location near the top of the nitrogen stripping column,
wherein the overhead nitrogen rich vapor stream comprises less
than 3 volume percent methane;
n) introducing the overhead nitrogen rich vapor stream
into the first heat exchanger;
and
o) using at least a portion of the overhead nitrogen rich
vapor stream as a refrigerant in the first heat exchanger to carry
out at least a portion of the cooling of step (a) and/or at least a
portion of the cooling of step ( c ), wherein the single closed-loop
mixed refrigerant system is the only closed-loop refrigeration
system used to cool the natural gas stream.
Appeal Br. 28-29 (Claims App.).
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Application 12/799,061
ANALYSIS
The Examiner determines independent claim 1 would have been
obvious in view of Phade, Swenson, and Hahn. Final Act. 2-6. The
Examiner finds Phade discloses process steps c) and h }-o) of the claimed
process, but not "wherein the single closed-loop mixed refrigerant system is
the only closed-loop refrigeration system used to cool the natural gas
stream." Id. at 2--4. Swenson, the Examiner finds, discloses process steps
a), b ), and "wherein the single closed-loop mixed refrigerant system is the
only closed-loop refrigeration system used to cool the natural gas stream."
Id. at 4. According to the Examiner, a skilled artisan would have known to
modify Phade with the process steps Swenson discloses to give "greater
control to the cooling of the feed stream as well as to assist in the cooling of
the feed stream." Id. This modification, the Examiner finds, further benefits
the system of Phade because
it will be capable of maintaining its liquid natural gas product
(128) in transportable (by ship) liquid phase since the closed loop
refrigeration system ... can be adjusted as required such that the
cooling duty of the liquid natural gas product (128) of Phade is
no longer needed to cool the natural gas feed stream (111 ).
Id. at 5. A skilled artisan would have modified Phade to include the closed
loop refrigeration system in Swenson, the Examiner determines, to provide
cooling with a greater degree of control, "since it is old and well known that
compressors and expansion valves may be adjusted to control efficiency and
capacity of a cooling system." Id.
For the claimed process steps d}-g), the Examiner relies on Hahn. Id.
at 5---6. The Examiner concludes further modifying Phade with these steps
of Hahn would have been obvious to a skilled artisan because it would
"provid[ e] a greater degree of control of reflux to the first vapor-liquid
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Application 12/799,061
separator ... , as well as to enhance separation by providing countercurrent-
mass exchange of the feed stream to itself within the first vapor-liquid
separator." Id. at 6. Moreover, the Examiner finds this modification would
result in sub-cooling the second portion via indirect heat exchange with the
expanded mixed refrigerant. Id.
Appellant does not dispute Swenson and Hahn disclose the claimed
process steps missing from Phade, but argue "the proposed combination of
Phade and Swenson cannot be used to support a proper primafacie case of
obviousness with respect to independent claim 1." Appeal Br. 26; see id. at
21-26. This is so, according to Appellant, because the "addition of
'compressors and expansion valves' as asserted by the Examiner would not
enhance the efficiency or control of the system of Phade." Id. at 22.
Appellant asserts that Phade teaches balancing internal refrigeration capacity
with refrigeration demand without the use of an external refrigerant "is a
major factor in the 'improved efficiency' of the system of Phade," which
undermines the Examiner's position that there would have been a need for
additional refrigeration. Id. at 23. In addition, Appellant contends the
Examiner erroneously suggests simply including an additional refrigerant to
the process of Phade (i.e., so as to not vaporize the stream of liquid methane)
would enable the process to maintain the stream of liquid methane
withdrawn from column 104 via line 128 in a transportable (by ship) liquid
phase. Id. According to Appellant, "simply electing not to vaporize the
stream of liquid methane withdrawn from column 104 via line 128 would
not convert the system of Phade to an LNG facility capable of forming a
'liquid natural gas product' that is 'transportable."' Id.
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We are persuaded the Examiner's reason for combining Phade and
Swenson in the claimed manner lacks a rational underpinning because
deficiencies exist with the evidence and technical reasoning given for why a
skilled artisan would have been led to the claimed combination. Phade and
Swenson disclose two different processes; Phade discloses a cryogenic
rectification process for separating nitrogen and methane, and Swenson
discloses a single mixed refrigerant, closed loop process for liquefj;ing
natural gas. Compare Phade Title, Figs. 1, 2 (and associated text), with
Swenson Title, Figs. la, lb (and associated text). The Examiner's analysis
fails to account for these process differences sufficiently. Nor does the
Examiner explain why the similarities between the Phade and Swenson
processes make Swenson's teachings regarding its refrigeration system
equally applicable to the process of Phade.
The Examiner simply finds Swenson teaches a closed loop vapor
compression refrigeration system that provides greater control to the cooling
of the feed stream and concludes a skilled artisan would have wanted to
provide cooling to the process of Phade with a greater degree of control.
Final Act. 4--5; Ans. 9. This rationale presumes inadequacies were known to
exist with the ability of the Phade process to control the cooling of the feed
stream. The Examiner, however, offers no evidence or technical reasoning
to support this presumption.
The Examiner does not make any finding of a known shortcoming
with the feed stream control in the Phade process or provide a technical
reason explaining why a skilled artisan would have perceived a shortcoming
with its control. For example, although the Examiner correctly notes
Swenson teaches a refrigeration system that enables its process to "bring the
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Application 12/799,061
combined cooling curve of the hot refrigerant and feed gas into relatively
close matching relationship to the heating curve of the cold refrigerant
stream" (Ans. 9 (quoting Swenson col. 2, 11. 16-50)), the Examiner does not
cite any evidence or explain why a similar need exists in the Phade process.
See id. And even presuming such a need exists, the Examiner still has not
shown the Phade process had known deficiencies creating such a
relationship that the refrigeration system in Swenson was known to address.
Similarly, the Examiner offers no evidence to support the finding that
adding Swenson's refrigeration system to Phade's process would maintain
the liquid natural gas product in a transportable liquid phase. Nor does the
Examiner explain how the combination would work to accomplish this
result. Contrary to the Examiner's contention, we note the refrigeration
system in Swenson is only one of several differences that exist between the
Phade process for separating nitrogen and methane and the Swenson
process for liquefying natural gas. Compare Phade Title, Figs. 1, 2 (and
associated text), with Swenson Title, Figs. la, lb (and associated text). This
fact more persuasively supports Appellant's assertion that the Phade process
does not become a process for creating transferable liquefied natural gas by
simply adding the Swenson refrigeration system, even if liquefied natural
gas occurs at various points within the Phade process. Appeal Br. 23-24.
With respect to core factual findings in a determination of
patentability, an examiner cannot establish a prima facie case based on
conclusions simply deemed to be basic knowledge or common sense. In re
Zurko, 258 F.3d 1379, 1385-86 (Fed. Cir. 2001). Rather, the examiner
"must point to some concrete evidence in the record in support of these
findings." Id.; see also Perfect Web Tech., Inc. v. InfoUSA, Inc., 587 F.3d
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1324, 1328 (Fed. Cir. 2009) (emphasizing same). It is incumbent upon the
examiner to establish a factual basis to support the legal conclusion of
obviousness. See In re Fine, 837 F.2d 1071, 1073 (Fed. Cir. 1988). In this
case, the Examiner's determination that it would have been obvious to
combine Phade with Swenson in the manner claimed is predicated on
findings not supported by a preponderance of the evidence. Thus, the
Examiner does not establish a sustainable case of obviousness of the subject
matter of independent claim 1, or its dependent claims 2--4, and 12.
Rejecting claims 13-15, the Examiner states, "Figure 2 of Phade, as
modified by Swenson and Hahn, and discussed above in claims 1--4 and 12,
necessarily teach all the structure required to meet all of the limitations of
claims 13-15." Final Act. 7. As a result, the Examiner's obviousness
determination of independent claim 13 incorporates the same errors
discussed above in the context of claim 1. Therefore, for the same reasons,
we do not sustain the Examiner's rejection of claim 13, as well as claims 14
and 15 depending therefrom.
DECISION
The Examiner's rejection of claims 1--4 and 12-15 is reversed.
REVERSED
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