Ex Parte Chantant et al

Patent Trial and Appeal Board

Jul 25, 2018

13807327 (P.T.A.B. Jul. 25, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/807,327 12/28/2012
23632 7590 07/27/2018
SHELL OIL COMPANY
POBOX576
HOUSTON, TX 77001-0576
FIRST NAMED INVENTOR
Francois Chantant
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.
TS8764-US-PCT 2217
EXAMINER
RAYMOND, KEITH MICHAEL
ART UNIT PAPER NUMBER
3744
NOTIFICATION DATE DELIVERY MODE
07/27/2018 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):
USPatents@Shell.com
Shelldocketing@cpaglobal.com
shellusdocketing@cpaglobal.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte FRANCOIS CHANT ANT and
WOUTER JAN MEIRING
Appeal2017-010591
Application 13/807 ,327
Technology Center 3700
Before: STEFAN STAICOVICI, LEE L. STEPINA, and
ARTHUR M. PESLAK, Administrative Patent Judges.
STAICOVICI, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Francois Chantant and Wouter Jan Meiring ("Appellants") 1' 2 appeal
under 35 U.S.C. § 134(a) from the Examiner's decision in the Final Action
( entered Apr. 21, 2016, hereinafter "Final Act.") rejecting claims 1, 4--1 0,
and 16. 3 We have jurisdiction under 35 U.S.C. § 6(b ).
1 Appellants did not provide page numbers on the Appeal Brief ( filed Oct.
19, 2016, hereinafter "Br."). However, for ease of referring to Appellants'
arguments, we have assigned page numbers 1 through 1 7 to the Appeal
Brief.
2 Appellants' Appeal Brief identifies Shell Oil Company as the real party in
interest. Br. 2
3 Claims 2 and 3 are canceled and claims 11-15 are withdrawn from
consideration. Br. 2, 13-17 (Claims App.).
Appeal2017-010591
Application 13/807,327
SUMMARY OF DECISION
We AFFIRM-IN-PART.
INVENTION
The invention relates to a method "for treating a hydrocarbon stream
comprising methane." Spec. 1, 11. 1-3.
Claim 1, reproduced below, is illustrative of the claimed subject
matter:
1. Method of treating a hydrocarbon stream compnsmg
methane, the method comprising:
- cooling at least a part of the hydrocarbon stream and a
main refrigerant stream by indirect heat exchanging against a
pre-cooling refrigerant, to provide a pre-cooled hydrocarbon
stream and a pre-cooled main refrigerant stream;
- passing the pre-cooled hydrocarbon stream to a first inlet
of an extraction column;
- discharging an effluent stream, in the form of a methane-
enriched hydrocarbon stream, from the extraction column via a
vapour outlet arranged gravitationally higher relative to the first
inlet into the extraction column, and a liquid methane-depleted
hydrocarbon stream from the extraction column via a liquid
outlet arranged gravitationally lower relative to the first inlet into
the extraction column;
- passing the effluent stream to a further heat exchanger;
- passing at least a part of the pre-cooled main refrigerant
stream to the further heat exchanger; and
- cooling both the effluent stream and the at least part of
the pre-cooled main refrigerant stream in the further heat
exchanger thereby providing a cooled methane-enriched
hydrocarbon stream and at least one cooled main refrigerant
stream;
wherein said passing of the effluent stream to the further
heat exchanger and said passing of the pre-cooled hydrocarbon
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Application 13/807,327
stream to the first inlet of the extraction column comprises
indirectly heat exchanging the effluent stream against the pre-
cooled hydrocarbon stream,
wherein said indirectly heat exchanging of the effluent
stream against the pre-cooled hydrocarbon stream comprises
passing the pre-cooled hydrocarbon stream from a first inlet into
an extraction column heat exchanger, through the extraction
column heat exchanger in indirect heat exchanging interaction
with the effluent stream, to a first outlet from the extraction
column heat exchanger, and passing the effluent stream from a
second inlet into the extraction column heat exchanger, through
the extraction column heat exchanger in indirect heat exchanging
interaction with the pre-cooled hydrocarbon stream, to a second
outlet from the extraction column heat exchanger, further
comprising extracting heat from at least one of:
- the pre-cooled hydrocarbon stream between the first inlet
into the extraction column heat exchanger and the first inlet of
the extraction column;
- the effluent stream between the vapour outlet from the
extraction column and the second outlet from the extraction
column heat exchanger;
- vapour and/or liquid within the extraction column in an
area being gravitationally minimally as high as the first inlet into
the extraction column and maximally as high as the vapour outlet
from the extraction column;
by heat exchanging against an auxiliary refrigerant stream.
REJECTIONS
I. The Examiner rejects claims 1, 4, 6, 9, and 16 under 35 U.S.C.
§ I03(a) as unpatentable over Truong et al. (EP 1 367 350 Al,
pub. Dec. 3, 2003, hereinafter "Truong"), Brostow et al. (US
2008/0016910 Al, pub. Jan. 24, 2008, hereinafter "Brostow")
and Buijs et al. (US 2008/0156036 Al, pub. July 3, 2008,
hereinafter "Buijs").
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Application 13/807,327
II. The Examiner rejects claim 5 under 35 U.S.C. § I03(a) as
unpatentable over Truong, Brostow, Buijs, and Spilsbury (US
2007/0245771 Al, pub. Oct. 25, 2007).
III. The Examiner rejects claim 7 under 35 U.S.C. § I03(a) as
unpatentable over Truong, Brostow, Buijs, and Roberts et al.
(US 6,119,479, iss. Sept. 19, 2000, hereinafter "Roberts").
IV. The Examiner rejects claim 8 under 35 U.S.C. § I03(a) as
unpatentable over Truong, Brostow, Buijs, and Kevenaar et al.
(US 2010/0037654 Al, pub. Feb. 18, 2010, hereinafter
"Kevenaar").
V. The Examiner rejects claim 10 under 35 U.S.C. § I03(a) as
unpatentable over Truong, Brostow, Buijs, and Paradowski (US
2004/0065113 Al, pub. Apr. 8, 2004).
VI. The Examiner rejects claim 16 under 35 U.S.C. § I03(a) as
unpatentable over Truong, Brostow, and Hikata et al. (US
6,357,105 Bl, iss. Mar. 19, 2002, hereinafter "Hikata"). 4
ANALYSIS
Rejection I
Claims 1, 4, 6, and 9
The Examiner finds that Truong discloses most of the features of
independent claim 1, but relies on Brostow to teach indirect heat exchanging
between methane enriched vapor stream 120 and precooled hydrocarbon
4 The Examiner refers to US 6,357,105 Bl as "Lee." Final Act. 17. Because
the first named inventor of US 6,357,105 Bl is "Hikata" and not "Lee," we
understand the Examiner's use of "Lee" to be a typographical error.
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Application 13/807,327
stream 112 in economizer heat exchanger 114. Final Act. 2--4; see also
Brostow, Fig. 1. The Examiner further finds that "[t]his indirect heat
exchange ... allows for control of the temperature of the overhead [ methane
enriched vapor] stream [ 120 withdrawn from] the extraction column [ 118]
such that the natural gas stream [ 122 that] enters the second heat exchanger
[ 124 is] at a temperature that is close to the temperature of the refrigerant
streams [152, 156] in the second heat exchanger." Final Act. 4 (citing
Brostow, para. 69). Thus, the Examiner reasons that it would have been
obvious to a person of ordinary skill in the art to alter the method of Truong
to include the indirect heat exchange step of Brostow "in order to allow for
control of the temperature of the overhead stream from the extraction
column such that the [ temperature of the] natural gas stream that enters the
second heat exchanger . . . is close to that of the refrigerant streams in the
second heat exchanger." Id. at 5. The Examiner further determines that
although Truong, as modified by Brostow, does not extract heat by heat
exchanging against an auxiliary refrigerant stream, it would, nonetheless,
have been obvious to the skilled artisan to further modify Truong to include
this feature based on the teachings of Buijs "in order to provide a cold liquid
reflux to the extraction column, thereby improving the recovery of heavier
hydrocarbons in the extraction column." Id. at 6; see also Buijs, Fig. 2.
Appellants argue that the modification based on Brostow "warms the
overhead [stream] ... for the purpose of minimizing the temperature
difference between the natural gas stream and the refrigerant of the main
heat exchanger (329 of Truong)," whereas the modification based on Buijs
"cools the overhead stream for the purpose of providing reflux for the
column, thereby improving recovery in the column." Br. 5 ( emphasis
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omitted). According to Appellants, it would not have been obvious to a
person of ordinary skill in the art "to modify a primary reference twice,
whereby the technical effect obtained by the second modification at least
partially cancels the technical effect obtained by the first modification." Id.
Appellants assert that although Brostow and Buijs address different
problems, because one modification cancels or worsens the other
modification, "introducing opposite and conflicting modifications (warming
and cooling of the same stream) is not something one of ordinary skill in the
art would do." Br. 6.
The Examiner responds that the proposed modifications of Truong' s
process require "a balancing between two separate considerations - the
temperature difference between the overhead stream and the
multicomponent refrigerant ( and therefore the heat stresses in the
downstream heat exchanger) and the recovery of heavy hydrocarbons."
Examiner's Answer 4 ( dated Dec. 21, 2016, hereinafter "Ans.") ( emphasis
omitted). According to the Examiner, although "the benefit of one
modification comes at the cost of the magnitude of the benefit of another
modification does not render [the] overall modification non-obvious." Id. at
4--5 (emphasis omitted). The Examiner considers that "[a] person having
ordinary skill in the art at the time of the invention would recognize that
these two modification may be made and their respective considerations
balanced as desired." Id. at 5 ( emphasis omitted).
Truong discloses discharging a methane-rich gas effluent stream
( overhead stream) at a temperature of -87° F, compressing in compressor
325, discharging in line 327 at a temperature of -47° F, and finally,
introducing the overhead stream into heat exchanger 329. Truong, paras. 59,
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60; Fig. 3. Brostow teaches using heat exchanger 114 to indirectly warm
methane enriched overhead stream 120 so that "the overhead stream in line
122 enters main heat exchanger 124 at about the same temperature as the
refrigerant streams [152, 156]" entering heat exchanger 124. Brostow,
paras. 62, 69; Fig. 1. Although Truong does not disclose the temperature of
refrigerant streams 401,403 entering heat exchanger 329, Truong discloses
that the temperature of the multicomponent refrigerant before being split
into streams 401, 403 is -30° F. Truong, para. 64. Thus, based on the
teachings of Bro stow, a person of ordinary skill in the art would readily
understand that upon providing Brostow's indirect heat exchanging step to
the process of Truong, as the Examiner proposes, Truong's methane-rich gas
overhead stream in line 327 would be heated from -47° F to around -30° F
so that the temperature of the overhead stream is about the same as the
temperature of refrigerant streams 401, 403.
Turning to Buijs, as the Examiner correctly finds, Buijs discloses that
an advantage of indirect heat exchanging vaporous overhead stream 111 is
that the lower the temperature of the overhead stream 111 is, the more C3+
components (methane) are separated out of the pre-cooled natural gas.
Buijs, para. 64, Fig. 2; see also Final Act. 6-7. Specifically, Buijs discloses
supplying pre-cooled natural gas, at a temperature of -25 °C (-13 °F), to
distillation column 105, discharging an overhead effluent gas stream 111
from distillation column 105, condensing ( cooling) the stream via heat
exchanger 113 ( using refrigerant 115) to form a mixture of light condensate
and light vapor, passing the mixture through reflux drum 117 such that the
light vapor is drawn to main heat exchanger 5, and the light condensate, at a
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temperature of between -25 and -65 °C (-85 °F), is fed as a cold liquid reflux
stream to distillation column 105. Buijs, paras. 56-61, 66, Fig. 2.
In this case, because an artisan must be presumed to know something
about the art apart from what the reference discloses, the skilled artisan
would understand that according to Buijs, the temperature of the overhead
effluent gas stream 111 is between about -25 °C (-13 °F) and about -45 °C
(-49 °F)5. See In re Jacoby, 309 F.2d 513, 516 (CCPA 1962). Therefore, as
the temperature of the methane-rich gas overhead stream of Truong, as
modified by Brostow, is about -30 °F, which is within Buijs' temperature
range, it is not clear why a person of ordinary skill in the art would further
cool the overhead stream, as the Examiner proposes. See Final Act. 6.
Stated differently, the reason proffered by the Examiner to further modify
the process of Truong, as modified by Brostow, namely, to "improve[] the
recovery of heavier hydrocarbons in the extraction column," can already be
adequately performed in the process of Truong, as modified by Brostow,
because the temperature of the methane-rich gas overhead stream of Truong,
as modified by Brostow, is -30 °F, which is within Buijs' temperature range.
Id.
Moreover, we do not see why a skilled artisan would further cool the
methane-rich gas overhead stream of Truong, prior to heating, because
Truong's overhead stream temperature of -47° Fis already within the
temperature range taught by Buij s, and any subsequent warming to prevent
heat stresses would offset additional prior cooling. We appreciate the
5 Calculated as the median average between the temperature of the pre-
cooled natural gas of -25 °C and the temperature range of the cold liquid
reflux stream of -25 to -65 °C, which are combined within column 105.
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Examiner's position that a person of ordinary skill in the art would want to
balance the effects of heating and cooling of the overhead stream. See Ans.
4--5. However, based on the disclosed operating temperatures of Truong,
Brostow, and Buijs, the skilled artisan looking to achieve a deeper C3+
extraction would understand that Truong's overhead stream need not be
cooled lower than -4 7° F (-44 °C), because -4 7 °F is within the required
range taught by Buijs, or may be cooled lower than -47° F (-44 °C), as Buijs
suggests, but would not subsequently be heated, as taught by Brostow,
because subsequent heating would negate the additional cooling and, thus,
would not achieve the deeper C3+ extraction of Buijs. We, thus, agree with
Appellants that "warming and cooling of the same stream[] is not something
one of ordinary skill in the art would do." Br. 6.
Accordingly, for the foregoing reasons, we do not sustain the rejection
of claim 1, and of claims 4, 6, and 9 depending therefrom, as unpatentable
over the combined teachings of Truong, Brostow, and Buijs.
Claim 16
Although Appellants state that claim 16 is canceled (see Br. 1 ),
Appellants did not file an amendment canceling claim 16 as required by 3 7
C.F.R. §§ 41.3 l(c) and 41.33 ("An appeal, when taken, is presumed to be
taken from the rejection of all claims under rejection unless cancelled by an
amendment filed by the applicant and entered by the Office."). Accordingly,
claim 16 is still pending, and Appellants have waived any argument of error.
Therefore, we summarily sustain the rejection of claim 16 as unpatentable
over Truong, Brostow, and Buijs. See Hyatt v. Dudas, 551 F.3d 1307, 1314
(Fed. Cir. 2008).
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Rejections II-VI
Claims 5, 7, 8, and 10 depend directly or indirectly from independent
claim 1. See Br. 13-14 (Claims App.). The Examiner's use of the teachings
of any of Spilsbury, Roberts, Kevenaar, and Paradowski does not remedy the
deficiencies of the combination of Truong, Brostow, and Buijs discussed
supra. See Final Act. 12-17. Therefore, for the same reasons as discussed
above, we likewise do not sustain the rejections under 35 U.S.C. § 103(a) of
claims 5, 7, 8, and 10.
Finally, with respect to Rejection VI, as noted supra, claim 16 is still
pending. Accordingly, as Appellants have waived any argument of error, we
likewise summarily sustain the rejection of claim 16 as unpatentable over the
combined teachings of Truong, Brostow, and Hikata.
DECISION
The Examiner's decision to reject claims 1 and 4--10 is reversed.
The Examiner's decision to reject claim 16 is affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 3 7 C.F .R. § 1.13 6( a )(1 )(iv).
AFFIRMED-IN-PART
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