SHELL OIL COMPANY

Patent Trials and Appeals Board

Jul 22, 2020

2019006468 (P.T.A.B. Jul. 22, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
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
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
13/846,238 03/18/2013 Mohan BALASUNDAR TS7124-US-NP 3422
23632 7590 07/22/2020
SHELL OIL COMPANY
P O BOX 576
HOUSTON, TX 77001-0576
EXAMINER
ATTEY, JOEL M
ART UNIT PAPER NUMBER
3763
NOTIFICATION DATE DELIVERY MODE
07/22/2020 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):
Shelldocketing@cpaglobal.com
USPatents@Shell.com
shellusdocketing@cpaglobal.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte MOHAN BALASUNDAR, ADRI VAN DRIEL,
AKASH GUPTA, and ADRIAAN SPAANDER
____________

Appeal 2019-006468
Application 13/846,238
Technology Center 3700
____________

Before MICHELLE R. OSINSKI, JEREMY M. PLENZLER, and
LEE L. STEPINA, Administrative Patent Judges.

OSINSKI, Administrative Patent Judge.
DECISION ON APPEAL

STATEMENT OF THE CASE
Appellant1 appeals under 35 U.S.C. § 134(a) from the Examiner’s
decision rejecting claims 1, 8–14, and 18.2 We have jurisdiction over the
appeal under 35 U.S.C. § 6(b).
We AFFIRM.

1 We use the term “Appellant” to refer to “applicant” as defined in 37 C.F.R.
§ 1.42. Appellant identifies the real party in interest as Shell Oil Company.
Br. 2.
2 Claims 2 and 15 are cancelled, and claims 3–7, 16, and 17 are withdrawn.
Br. 17, 18, 21 (Claims App.).
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THE CLAIMED SUBJECT MATTER
Claims 1 and 14 are independent. Claim 1 is reproduced below.
1. A method of preparing a cooled hydrocarbon stream from a
hydrocarbon feed stream, comprising:
- circulating a cooling fluid consisting of a mixed
refrigerant composition in a loop along a circulation direction
wherein, in consecutive order,
passing the cooling fluid through an expander to
provide an expanded cooling fluid,
allowing the expanded cooling fluid to
progressively evaporate as the expanded cooling fluid
flows through a cold side heat exchanging channel, by
allowing the expanded cooling fluid to flow through a first
section of the cold side heat exchanging channel in contact
with a first cold surface of a first heat exchanging fluid
barrier whereby liquid from the expanded cooling fluid is
continuously transformed to vapour,[]thereby forming a
residual liquid portion of not evaporated expanded cooling
fluid, and subsequently allowing the residual liquid
portion to continue its flow through a second section of the
cold side heat exchanging channel in contact with a second
cold surface of a second heat exchanging fluid barrier
whereby the residual liquid is continuously vaporized,
compressing the vapour and the vaporized residual
liquid to provide a compressed vapour,
transferring heat from the compressed vapour to
ambient, and
closing the loop by again passing the cooling fluid
through the expander;
- progressively cooling a hydrocarbon feed stream as it
flows through a second warm section of a warm side heat
exchanging channel in contact with a second warm surface of
said second heat exchanging fluid barrier, thereby forming a pre-
cooled hydrocarbon feed stream consisting of a mixture of
vapour and liquid phases, by allowing the hydrocarbon feed
stream to lose heat to the evaporating residual liquid passing
through the second section of the cold side heat exchanging
channel;
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- passing the pre-cooled hydrocarbon feed stream into a
column;
- drawing an overhead vapour hydrocarbon stream from
the column;
- progressively condensing the overhead vapour
hydrocarbon stream as it flows through a first warm section of
the warm side heat exchanging channel in contact with a first
warm surface of said first heat exchanging fluid barrier, until the
overhead vapour hydrocarbon stream is partially condensed and
forms a partially condensed hydrocarbon stream, by allowing the
overhead vapour hydrocarbon stream to lose heat to the
evaporating expanded cooling fluid passing through the first
section of the cold side heat exchanging channel;
- separating the partially condensed hydrocarbon stream
into a liquid component and a vaporous component, wherein the
vaporous component comprises the cooled hydrocarbon stream;
- feeding the liquid component into the column as reflux
stream,
wherein the first heat exchanging fluid barrier and the
second heat exchanging fluid barrier are both located within a
single heat exchanger.

EVIDENCE
The Examiner relied on the following evidence in rejecting the claims
on appeal:
Paradowski US 4,334,902 June 15, 1982
Roberts ’531 US 6,308,531 B1 Oct. 30, 2001
Roberts ’915 US 2010/0281915 A1 Nov. 11, 2010
Don W. Green & Robert H. Perry, Perry’s Chemical Engineers’
Handbook (8th ed. 2008) (hereinafter “Perry”)
REJECTIONS
I. Claims 1, 8–11, 13, 14, and 18 stand rejected under 35 U.S.C.
§ 103(a) as unpatentable over Roberts ’531, as evidenced by Perry,
and Roberts ’915. Final Act. 3–15.
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II. Claim 12 stands rejected under 35 U.S.C. § 103(a) as
unpatentable over Roberts ’531, as evidenced by Perry, Roberts ’915,
and Paradowski. Id. at 15–16.
OPINION
Rejection I
Appellant presents arguments for independent claim 1 and relies on
the same arguments for independent claim 14 and dependent claims 8–11,
13, and 18. Appeal Br. 7–13. We select claim 1 as representative of the
issues that Appellant presents in the appeal, and claims 8–11, 13, 14, and 18
stand or fall therewith. See 37 C.F.R. § 41.37(c)(1)(iv).
The Examiner finds that Roberts ’531 teaches most of the limitations
of independent claim 1 (Final Act. 3–6), but acknowledges that Roberts ’531
fails to teach “separating the partially condensed hydrocarbon stream into a
liquid component and a vaporous component wherein the vaporous
component comprises the cooled hydrocarbon stream” and “feeding the
liquid component into the column as [a] reflux stream” (id. at 6). The
Examiner finds that Roberts ’915
teaches a method for the liquefaction of natural gas (see Fig. 1),
wherein a feed stream (100) is pre-cooled in a precooling
apparatus (101) thereby yielding a precooled stream (102). The
precooled stream is then fed to a scrub column (103) which
produces an overhead stream (104) which is then partially
condensed in the precooling apparatus (in stream 107 in the
precooling apparatus), separated into a liquid stream (111/113)
and a vapor stream (114) in a separator (110), and the liquid
stream is fed to the scrub column as a reflux stream (via lines 111
and 113; para. 47).
Id. at 6. The Examiner concludes that it would have been obvious “to
modify Roberts ’531 to separate a portion of the partially condensed
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overhead stream (126) and to employ the liquid fraction as a reflux stream
[in connection with scrub column (108)] as this would improve the
separation performance of the column [(108)]of the method of . . . Roberts
’531.” Id. at 6–7.
Appellant argues that Roberts ’531 teaches a stripper column 108,
rather than a scrub column as explicitly recited. Br. 8–9. In support of
Roberts ’531 teaching a stripper column, Appellant asserts that Roberts ’531
states that “‘the scrub column is shown with only a stripping section,’” that
the column 108 has a reboiler at the bottom, and that “stream 126 of Roberts
’531 is somewhere near 66.5 bara . . . [which] is too high to scrub the vapor
and remove the heavy hydrocarbons.” Id. (quoting Roberts ’531 8:9–10).
Under the assumption that Roberts ’531 teaches a stripper column, Appellant
asserts that the main objective of stripper column 108 is “to reduce the
amount of light hydrocarbons in the bottom stream.” Id. (emphasis added).
Appellant continues that Roberts ’915, on the other hand, teaches scrub
column 103 with a reflux being provided at the top thereof in order to
“remove heavy hydrocarbons from the top stream.” Id. (emphasis added).
According to Appellant, “Roberts ’531 and Roberts ’915 therefore
serve different technical purposes with different associated technical
considerations, making combining these documents unlikely.” Br. 9. In
particular, Appellant asserts that the Examiner’s proposed modification of
Roberts ’531 “would require, at least, turning the stripper column 108 of
Roberts ’531 into a scrub column,” which Roberts ’531 teaches away from.
Id. In addition, Appellant asserts that the Examiner’s proposed modification
of Roberts ’531 would also require “changes to the setup of fractionation
section 112; and changes to stream 118 and the influence thereof on heat
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exchanger 106.” Id. at 10. That is, Appellant argues that the rejection
“lacks proper substantiation how ‘increased rectification’ [to remove heavier
components in overhead product stream 120 of scrub column 108] logically
combines with ‘ . . . propane and lighter components in stream 118 . . .
[being] recombined with the overhead product of the scrub column to form
purified feed stream 120.’” Id. at 10–11 (citing Roberts ’531 8:19–23).
The Examiner responds that “scrubbing (also called rectifying) and
stripping in fractional distillation are not mutually exclusive.” Ans. 3
(emphasis omitted). The Examiner further responds that Roberts ’531 itself
explicitly discloses that although scrub column 108 “is shown with only a
stripping section,” “[i]n other instances, a rectifying section with a
condenser can be employed for removal of heavy contaminants such as
benzene to very low levels” and that “any suitable modification to scrub
column [108] can be made” such as, for example, that “a heavier component
such as butane may be used as the wash liquid.” Id. (quoting Roberts ’531
8:9–16. Considering the explicit disclosure in Roberts ’531 of a scrub
column that includes a rectifying section and the express suggestion of
providing a wash liquid for removal of heavy contaminants (Roberts ’531
8:9–16) on which the Examiner relies (Ans. 4), we are not persuaded by
Appellant’s argument that Roberts ’531 teaches only a stripping column, nor
that Roberts ’531 teaches away from a scrub column. Accordingly, we are
not persuaded that the reasoning underlying the Examiner’s proposed
combination lacks rational underpinnings because of purported technical
differences between the supposed stripping column of Roberts ’531 and the
scrub column of Roberts ’915.
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We have also considered Appellant’s argument that any modification
of Roberts ’531 to include a rectifying section that employs a reflux stream
would require further changes to the fractionation section 112, stream 118,
and the influence on heat exchanger 106. Br. 10–11. Appellant’s argument
is premised on the idea that modification of Roberts ’531 to separate a
portion of the partially condensed overhead stream 126 and employ the
liquid fraction as a reflux stream in order to improve separation performance
of column 108 (Final Act. 6–7) does not logically combine with the
disclosure in Roberts ’531 that bottoms product 110 of scrub column 108
enters fractionation section 112 where propane and lighter components in
stream 118 are passed through heat exchanger 106 and ultimately
recombined with the overhead product of scrub column 108 to form
stream 120. Br. 10–11; Roberts ’531 8:17–23.
We do not find such an argument persuasive for the reasons set forth
by the Examiner in the Answer. In particular, as explained by the Examiner,
“[t]he rejection does not propose to implement the reflux of Roberts ’915 in
Roberts ’531 to remove propane hydrocarbons that Roberts ’531 teaches
‘recollecting . . . and recombining.’” Ans. 7–8. Rather, the rejection
proposes to implement the reflux of Roberts ’915 in Roberts ’531 in order to
remove hydrocarbons heavier than propane (e.g., benzene). Id. at 7; Roberts
’531 8:10–12, 17–24. Moreover, as mentioned above, because “Roberts
’531 expressly discloses providing reflux to its scrub column” and further
“that ‘any suitable modification to scrub column [108] can be made’
routinely by the ordinary artisan” (id. (quoting Roberts ’531 8:14–15)), it
would appear that any purported changes that Appellant argues might be
necessary when modifying Roberts ’531 to implement a reflux “would be
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routine undertaking for the ordinary artisan” (id.). In sum, we do not agree
with Appellant that the Examiner’s proposed modification is based on
reasoning that lacks rational underpinnings.
Appellant also argues that “Roberts ’915 lacks any details, pointers or
indication that stream 108 [leading into streams 111/113 and ultimately
passing into column 103 as reflux] would originate from a different section
of pre-cooling apparatus 101 th[a]n pre-cooled stream 102 [passing into
column 103 as a pre-cooled feed stream]” and the rejection “lacks
substantial reasoning how a combination of Roberts ’531 with Roberts ’915
would include the required modifications and adaptations for the disclosure
of Roberts ’915.” Br. 12. Appellant argues that the origination of the
streams from different sections of pre-cooling apparatus 101 is required by
virtue of the recitation in the claims of “progressively cooling a hydrocarbon
feed stream as it flows through a second warm section of a warm side heat
exchanging channel . . . [and] passing the pre-cooled hydrocarbon feed
stream into a column” and “progressively condensing the overhead vapour
hydrocarbon stream [from the column that is ultimately separated into a
liquid component that is fed into the column as a reflux stream] as it flows
through a first warm section of the warm side heat exchanging channel.”
Br. 16–17 (Claims App.) (emphasis added).
As an initial matter, the Examiner’s rejection relies on Roberts ’531 as
teaching the identified claim limitations. Final Act. 4–5 (citing Roberts ’531
7:64, 7:62–8:2, 8:23–26). Therefore, any failure of Roberts ’915 to teach the
identified claim limitations is not persuasive of error by the Examiner. See
Ans. 9 (“Appellant[’s] allegation that ‘Roberts ’915 lacks any details,
pointers or indication that stream 108 would originate from a different
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section’ of a heat exchanger does not address the actual grounds of rejection.
The Examiner has cited to Roberts ’531 as showing cooling a feed stream
and overhead vapor stream in different sections of a heat exchanger.”).
Moreover, the Examiner finds that “Roberts ’915 explicitly teaches cooling
an overhead vapor hydrocarbon stream (107 to 108) in ‘first warm section’
of a heat exchanger (right side of 101) while cooling a feed stream in a
‘second warm section’ (left side of 101) and the ‘first warm section.’” Id.
The Examiner explains that “the claim language does not preclude . . .
cooling of a feed stream in more than a second warm section, as taught by
Roberts ’915.” Id. at 9–10. Thus, the Examiner takes the position that the
disclosure of Roberts ‘915 is sufficient to disclose the requirements of the
claim. Appellant does not identify error in the position taken by the
Examiner. Accordingly, Appellant’s argument that the Examiner has not
explained adequately how Roberts ’915 would be modified and/or adapted
when combined with Roberts ’531 (Br. 12) is not persuasive.
For the foregoing reasons, Appellant does not apprise us of error in
the Examiner’s determination that Roberts ’531, as evidenced by Perry, and
Roberts ’915 renders obvious the subject matter of independent claim 1.
Accordingly, we sustain the rejection of claim 1, and claims 8–11, 13, 14, 18
falling therewith, under 35 U.S.C. § 103(a) as unpatentable over Roberts
’531, as evidenced by Perry, and Roberts ’915.
Rejection II
In contesting the rejection of claim 12, Appellant relies on the same
arguments and reasoning we found unpersuasive in connection with
independent claim 1. See Br. 13–14. Accordingly, we also sustain the
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rejection of claim 12 under 35 U.S.C. § 103(a) as unpatentable over Roberts
’531, as evidenced by Perry, Roberts ’915, and Paradowski.

CONCLUSION
In summary:
Claims
Rejected
35
U.S.C. §
Reference(s)/Basis Affirmed Reversed
1, 8–11,
13, 14, 18
103(a) Roberts ’531, as
evidenced by Perry,
Roberts ’915
1, 8–11, 13,
14, 18

12 103(a) Roberts ’531, as
evidenced by Perry,
Roberts ’915,
Paradowski
12
Overall
Outcome
1, 8–14, 18

No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv).
AFFIRMED