IFP Energies nouvelles

Patent Trials and Appeals Board

Apr 26, 2021

2020003400 (P.T.A.B. Apr. 26, 2021)

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.
15/223,562 07/29/2016 Fabrice DIEHL PET-3096 7475
23599 7590 04/26/2021
MILLEN, WHITE, ZELANO & BRANIGAN, P.C.
2200 CLARENDON BLVD.
SUITE 1400
ARLINGTON, VA 22201
EXAMINER
LI, JUN
ART UNIT PAPER NUMBER
1796
NOTIFICATION DATE DELIVERY MODE
04/26/2021 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):
docketing@mwzb.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte FABRICE DIEHL and JEAN-CHRISTOPHE VIGUIE
Appeal 2020-003400
Application 15/223,562
Technology Center 1700
Before TERRY J. OWENS, JULIA HEANEY, and JANE E. INGLESE,
Administrative Patent Judges.
HEANEY, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1–3 and 5–13. See Final Act. 1. We
have jurisdiction under 35 U.S.C. § 6(b).
We REVERSE and enter a NEW GROUND OF REJECTION
pursuant to our authority under 37 C.F.R. § 41.50(b).

1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R.
§ 1.42. Appellant identifies the real party in interest as IFP Energies
nouvelles. Appeal Br. 1.
Appeal 2020-003400
Application 15/223,562
2

CLAIMED SUBJECT MATTER
The claims are directed to a process for the preparation of a catalyst
intended for use in a Fischer-Tropsch reaction. Claim 1, reproduced below,
is illustrative of the claimed subject matter:
1. A process for the preparation of a Fischer-Tropsch reaction
catalyst comprising, the following successive stages:
a) providing a support impregnated with a solution of
cobalt nitrate,
b) oxidizing said support impregnated with a cobalt nitrate
solution at a calcining temperature comprised between 410°C
and 450°C in order to produce a catalyst precursor comprising
cobalt oxides,
c) providing a reducing gas, comprising at least 99% by
volume of hydrogen and less than 200 ppmvol of water,
d) contacting said catalyst precursor with the reducing gas
by circulating the flow of reducing gas over a bed of said catalyst
precursor, at a final reduction temperature at least l0°C less than
the calcining temperature, maintaining the final reduction
temperature for 10-24 hours, reducing the cobalt oxides to
metallic cobalt and producing a reduced catalyst and a flow of
reducing gas laden with water,
e) reducing the water content of the flow of reducing gas
laden with water recovered in stage d), producing a flow of
reducing gas comprising less than 200 ppmvol of water, then
f) recycling at least a part of the flow of reducing gas to
stage d),
in which in stage d), the reducing gas is maintained at a
water content of less than 10,000 ppmvol.
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Van De Loosdrecht US 2010/0304955 A1 Dec. 2, 2010
Inga US 2012/0298551 A1 Nov. 29, 2012
Takahama US 2016/0296913 A1 Oct. 13, 2016
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Takahama WO 2015/072573 A1 May 21, 2015

REJECTION
Claims Rejected 35 U.S.C. § Reference(s)/Basis
1–3, 5–13 103 Van De Loosdrecht,
Inga, Takahama2

OPINION
The Examiner finds that Van De Loosdrecht discloses a process of
reactivating a spent cobalt Fischer-Tropsch synthesis catalyst comprising the
steps of forming a slurry of a particulate catalyst support, impregnating the
catalyst support with a cobalt nitrate solution, and calcining the impregnated
support in the presence of oxygen-containing air to obtain a catalyst
precursor containing cobalt oxide, wherein the calcining temperature is 200°
to 400° C. Final Act. 2–3 (citing ¶¶ 14, 41, 59, 64, incorporating by
reference WO 01/39883). The Examiner further finds that Van De
Loosdrecht discloses obtaining an active catalyst by reducing the catalyst
precursor, using the catalyst in Fischer-Tropsch synthesis, and regenerating
(“reactivating”) the spent catalyst by reducing the same. Id. at 3 (citing
¶¶ 40, 41, incorporating by reference WO 03/035257 page 1 lines 10–13,
page 2 lines 11–27, page 3 lines 11–15).
The Examiner finds Van De Loosdrecht does not teach a calcining
temperature between 410° and 450° C, but that the disclosed calcining

2 The Examiner relies upon the U.S. pre-grant publication of record as the
English language equivalent. We do likewise.

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temperature is close to the claimed range and that it would have been
obvious to a person of ordinary skill in the art to select a calcining
temperature within the claimed range by routine optimization, in order to
obtain a desired cobalt oxide catalyst. Final Act. 3 (citing MPEP §
2144.05(I)).
Appellant argues that Van De Loosdrecht is primarily concerned with
a process of regenerating a spent catalyst. Appeal Br. 3–4. Appellant argues
that, to the extent that Van De Loosdrecht teaches preparing a “fresh
catalyst” (e.g., one that is not spent) in its examples, the reducing
temperature (425° C) is higher than the calcination temperature (250° C).
Appeal Br. 4 (citing Van De Loosdrecht ¶¶ 64–65). Appellant argues that,
after using the fresh catalyst, Van De Loosdrecht regenerates the resulting
spent catalyst by subjecting it to dewaxing, oxidation at 250° C, and
reduction under hydrogen at 425° C. Id. (citing Van De Loosdrecht ¶¶ 78,
81, 82). Appellant argues that Van De Loosdrecht ¶ 14 describes oxidizing
spent catalyst during the process of regenerating the spent catalyst. Id.
Appellant disputes that Van De Loosdrecht teaches a calcination
temperature as claimed for preparing a fresh catalyst. Appeal Br. 2–4; 3
Reply Br. 3. In reply, the Examiner argues that the language of claim 1 does
not require a “fresh catalyst,” and that the transitional phrase “comprising”

3 Appellant addresses previously withdrawn rejections of claims 1–11 and
13 under 35 U.S.C. § 103 as being unpatentable over Van De Loosdrecht in
view of Inga; and of claim 12 under 35 U.S.C. § 103 as being unpatentable
over Van De Loosdrecht in view of Inga further in view of Ono (US
2012/0329890 A1). Appeal Br. 2–7. See Ans. 10. We nonetheless address
Appellant’s contentions to the extent they are responsive to findings on the
Final Rejection.
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does not exclude steps for regenerating a catalyst (dewaxing, oxidation, and
reduction). Ans. 10–11. The Examiner does not address the calcination
temperature in relation to the reduction temperature disclosed by Van De
Loosdrecht ¶¶ 64–65, as argued by Appellant. Appeal Br. 4.
Having considered the Examiner’s findings and Appellant’s
arguments as to Van De Loosdrecht’s teachings, we agree with Appellant
that Van De Loosdrecht does not teach the calcining or reducing
temperatures required by steps (b) and (d) of claim 1._The claimed process
is for preparing a Fischer-Tropsch reaction catalyst. In relevant part, step (a)
of claim 1 is providing a support impregnated with a solution of cobalt
nitrate. Step (b) is oxidizing the support impregnated with a solution of
cobalt nitrate at a calcining temperature between 410° and 450° C to produce
a catalyst precursor comprising cobalt oxides. At issue are the calcining
temperature in step (b) and the final reduction temperature (in relation to the
calcining temperature) in step (d).
The Examiner interprets Van De Loosdrecht as teaching a process of
regenerating a spent catalyst:
including making a fresh catalyst, then using it and regenerating
it […] wherein the process of making a fresh catalyst includ[es]
impregnating a support with a slurry containing cobalt salt (e.g.
cobalt nitrate) […], drying the impregnated catalyst support,
calcining the impregnated support to obtain a catalyst precursor;
and reducing the catalyst precursor, to obtain an active cobalt
Fischer-Tropsch synthesis catalyst
Ans. 11 (citing Van De Loosdrecht ¶¶ 41, 46, 51).
While we agree with the Examiner that claim 1 does not recite “fresh
catalyst” and the transitional phrase “comprising” is inclusive, we do not
agree with the Examiner’s finding that the catalyst regeneration process
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steps of Van De Loosdrecht teach the steps of claim 1. Van De Loosdrecht
¶ 41 describes preparing an active Fischer-Tropsch synthesis catalyst
comprising impregnating a support with a slurry containing cobalt salt;
drying and calcining the impregnated support to obtain a catalyst precursor;
and reducing the catalyst precursor to produce an active catalyst. The same
paragraph then describes regenerating a spent catalyst as a subsequent,
separate process from preparing active catalyst from an impregnated
support. Id. We accordingly interpret Van De Loosdrecht as teaching a
process for preparing a fresh catalyst (e.g., active catalyst from an
impregnated support) and a process for regenerating spent catalyst as
different, non-overlapping processes.
The Examiner cites Van De Loosdrecht ¶¶ 12, 14, 17 as teaching
calcination at a temperature in the presence of air or oxygen. Ans. 11.
Appellant argues that the oxidation temperature of Van De Loosdrecht ¶ 14
refers to the regeneration process rather than to preparation of a fresh
catalyst. Appeal Br. 4. We agree that the cited paragraphs do not refer to
preparing fresh catalyst. Van De Loosdrecht ¶¶ 3–40 only describe a
process for regenerating spent catalyst and, so, Van De Loosdrecht ¶¶ 12,
14, 17 pertain to calcining spent catalyst. In contrast, step (b) of claim 1
describes “oxidizing said support impregnated with a cobalt nitrate solution
at a calcining temperature[…].” Because a spent catalyst is not the same as
a support impregnated with cobalt nitrate solution, we conclude that Van De
Loosdrecht does not support the Examiner’s determination that a person of
ordinary skill in the art would have understood that Van De Loosdrecht
¶¶ 12, 14, 17 teaches oxidizing a solution impregnated support as recited in
claim step (b).
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To extent that Van De Loosdrecht teaches a calcination temperature
for preparing a fresh catalyst, we find that the disclosed temperatures are
close to but do not overlap those recited in step (b) of claim 1; and Van De
Loosdrecht does not teach a reduction temperature in relation to the
calcination temperature as recited in claim step (d). Van De Loosdrecht ¶ 59
teaches calcining an impregnated support at 200° to 400° C. The examples
of Van De Loosdrecht prepare a fresh catalyst by calcining an impregnated
catalyst support twice at 250° C, followed by reduction under hydrogen gas
to a final reduction temperature of 425° C. Id. at ¶¶ 64–65. This supports
Appellant’s position that, where Van De Loosdrecht teaches a calcination
temperature of “fresh catalyst,” it does so at a lower temperature than the
reduction temperature. Appeal Br. 4.
We find that a preponderance of evidence of record does not support
the Examiner’s conclusion that claims 1–3 and 5–13 are obvious over Van
De Loosdrecht in view of Takahama and Inga. We reverse the rejection
under § 103 and enter a new ground of rejection under 37 C.F.R § 41.50(b).

New Ground of Rejection
In accordance with 37 C.F.R § 41.50(b), we enter the following new
ground of rejection.
Claims 1–3 and 5–13 are rejected under 35 U.S.C. § 103 as obvious
over Takahama (WO 2015/072573 A1) in view of Inga.
Takahama teaches producing a catalyst for Fischer-Tropsch synthesis
comprising providing a carrier precursor by impregnating carrier materials
with an aqueous solution of cobalt nitrate, followed by drying and calcining
the impregnated carrier at 450° C to obtain an unreduced catalyst. Takahama
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¶¶ 40, 50, 81. The unreduced catalyst is then reduced under a hydrogen gas
stream in a rotary kiln at 350° C for 7 hours to obtain an activated catalyst.
Id. at ¶ 84.
Takahama also teaches calcining the catalyst precursor at a
temperature of 400° to 450° C to obtain high dispersibility of the cobalt
compound. Id. at ¶ 55.
Takahama further describes conducting a reduction treatment by
contacting the calcined catalyst precursor with a flow of reducing gas, where
the gas contains 95 volume percent or more of hydrogen. Id. at ¶¶ 57–59.
The reducing gas is pure hydrogen or contains hydrogen with an inert gas
like nitrogen. Id. The reduction temperature is 250° to 500° C, preferably
350° to 450° C for sufficient cobalt atom reduction without reducing
catalytic activity due to aggregation of formed metal cobalt. Id. at ¶ 61. The
reduction time is about 0.5 to 60 hours, but can be adjusted depending upon
the temperature, atmosphere, and the apparatus employed. Id. at ¶ 62.
Takahama teaches conducting reduction in fluidized beds or rotary kilns for
optimal contact efficiency of the reducing gas. Id. at ¶ 64. The degree of
cobalt atom reduction is reflected in part by the amount of water generated
in the apparatus during catalyst reduction. Id. at ¶ 70.
Inga is directed to a system for activating a Fischer-Tropsch catalyst
utilizing activation gas streams containing less than 99.5 volume percent of
hydrogen. ¶¶ 8–10. “Activation” refers to reducing a catalyst precursor to
yield an active catalyst. Id. at ¶¶ 8, 28.
Figure 1, reproduced below, is a schematic for Inga’s system 100 for
activating a Fischer-Tropsh catalyst.
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Figure 1 depicts system 100 comprising: separation apparatus 10 configured
for separating a product gas comprising primarily hydrogen from a gas
stream comprising hydrogen; activation reactor 20 fluidly connected with
the separation apparatus via an activation gas inlet line 15 whereby the
product gas is introduced into the activation reactor; circulation loop 30
fluidly connecting a gas outlet 25 of the activation reactor with the activation
gas inlet line (45), or with another gas inlet of the activation reactor and
fluidly connecting the activation reactor with one or more apparatus 40
configured for removal of water (35). Id. at ¶¶ 18, 40, 80–81, Fig.1.
Separation apparatus 40 is configured to provide a product gas comprising
less than about 99 volume percent hydrogen. Id. By removing water from
gas exiting the activation reactor, separation apparatus 40 lowers the gas
dew point and promotes catalyst activity. Id. at ¶¶ 81, 82. A dryer
downstream from separation apparatus 40 further reduces water content in
the gas to less than 100 ppmvol. Id. at ¶ 84. Other than the removal of
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water, system 100 is a closed loop/closed system and the dewatered gas is
recycled back to the activation reactor through circulation loop 30. Id. at
¶ 80.

Obviousness of Claim 1
Takahama teaches a process for producing a Fischer-Tropsch
synthesis catalyst by providing a support impregnated with cobalt nitrate
solution as in step (a); oxidizing the support impregnated with cobalt nitrate
solution as in step (b); providing a reducing gas comprising at least 99% by
volume of hydrogen as in step (c); and contacting the catalyst precursor with
a flow of reducing gas to a final reduction of at least 10° C less than the
calcining temperature for a period within 10 to 24 hours as in step (d).
When the reducing gas is pure hydrogen or comprises an inert gas and at
least 99% by volume of hydrogen (Id. at ¶ 59), the water gas contacted with
the unreduced catalyst has less than 200 ppmvol of water.
Takahama does not teach the water content of the reducing gas as in
(d), reducing the water content in the recovered reducing gas as in (e), or
recycling at least a part of the flow of reducing gas as in (f).
Inga teaches activing the Fischer-Tropsch catalyst therein by
circulating an activating gas over an unactivated catalyst and heating the
reactor up to an activating temperature (400° C or less) until the catalyst is
reduced and a certain water concentration is attained for maximum catalyst
activity without sintering. ¶¶ 78, 80, 89. The activating gas comprises less
than 99.5 volume percent hydrogen and may contain limited water vapor,
e.g., 0.5 ppmvol water vapor, or no water vapor (e.g., hydrogen gas with
carbon monoxide or an inert gas) to minimize negative effects on activation.
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Id. at ¶¶ 18, 73. On exiting the activation reactor, the gas water content is
reduced to less than 100 ppmvol and the gas recycled so as to promote
catalyst activity. Id. at ¶¶ 82, 84. Paragraph 87 teaches circulating the gas
until the gas concentration of carbon monoxide is below about 1 ppmvol,
water below 100 ppmvol, or both.
A person of ordinary skill in the art would have found it obvious to
modify Takahama’s process by controlling the water content of the reducing
gas, reducing the water content in the recovered reducing gas, and recycling
at least a part of the flow of reducing gas, as taught by Inga, in order to
minimize negative impact on catalyst activation and promote catalyst
activity.

Obviousness of Claim 2
Takahama does not specifically disclose a flow rate of the reducing
gas of 1 Nm3/h/kg of catalyst precursor to 6 Nm3/h/kg of catalyst precursor.
Takahama ¶¶ 65, 67 teaches that the volume flow rate of the reduction
gas/volume of the unreduced catalyst (GHSV) is 200 to 1500 h-1. Reduction
is conducted at a temperature of 350° to 450° C and at a pressure of from
normal pressure to about 5 MPa for about 0.5 to 60 hours. Id. at ¶¶ 61–62.
The reduction time can be adjusted depending upon the temperature,
atmosphere, and the apparatus employed. Id. at ¶ 62. The reduction
temperature and pressure conditions overlap with those recited in claim 3.
Because Takahama teaches contacting the catalyst precursor with a
reducing gas under time, temperature, or pressure conditions optimizable or
overlapping those in the claimed process, one of ordinary skill in the art
would reasonably have been able to determine that the flow rate as
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calculated in Nm3/h/kg overlaps the presently claimed range. It is
incumbent upon Appellant to demonstrate otherwise.

Obviousness of Claim 3
Takahama carries out reduction at a pressure of from normal pressure
to about 5 MPa. ¶ 62. Reduction is preferably conducted at a final
temperature of 350 to 450° C to sufficiently reduce the cobalt atoms without
reducing catalytic activity due to aggregation of the metal cobalt. Id. at ¶ 61.

Obviousness of Claim 5
Takahama contacts the calcined catalyst precursor with a reducing gas
to a final reducing temperature over a period as claimed, but does not
disclose a temperature gradient for increasing the temperature of the
reducing as.
Inga ¶ 90 teaches raising the activation reactor temperature serially at
a rate of 0.15° to 3° C/min. to maximize catalyst activity without sintering.
As Inga teaches a temperature gradient that overlaps that presently
claimed, it would have been prima facie obvious to a person of ordinary skill
in the art to conduct reduce the catalyst precursor by progressively
increasing the reducing gas temperature over the claimed range so as to
maximize catalyst activity without sintering the catalyst.

Obviousness of Claim 6
Takahama calcines the catalyst precursor for 3 hours. ¶ 81.

Obviousness of Claim 7
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Takahama does not describe cooling the reducing gas recovered from
reducing treatment and eliminating water produced by cooling.
Inga ¶¶ 82–83 teaches cooling and removing water condensate from
the exiting reducing gas in order to lower the gas dew point, maintain lower
water partial pressure, and increase catalyst activity.
It would have been prima facie obvious to a person of ordinary skill in
the art to cool and remove water from exiting reducing gas to increase
catalyst activity by lowering the gas dew point and maintaining a lower
water partial pressure.

Obviousness of Claim 8
Takahama does not teach bringing reducing gas recovered from
reducing treatment in contact with at least one molecular sieve.
Inga ¶ 84 teaches contacting reducing gas exiting the reducing
apparatus with a molecular sieve in order to remove at least some of the
water. Removing water from the gas lowers the gas dew point and promotes
catalyst activity. Id. at ¶ 82.
It would have been prima facie obvious to a person of ordinary skill in
the art to promote catalyst activity by removing water from gas exiting the
reducing apparatus.

Obviousness of Claim 9
Takahama does not disclose contacting a molecular sieve with a
portion of recovered water-laden reducing gas, then introducing the portion
with the reducing gas at the inlet for reducing the water content of the gas.
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Inga teaches reducing the gas water content on exiting the activation
reactor to less than 100 ppmvol and the gas recycled so as to promote
catalyst activity. ¶¶ 82, 84. Inga ¶ 18 teaches that the circulation loop
connects the gas outlet reactor out of the activator apparatus with a gas inlet
or with a water removal apparatus.
It would have been prima facie obvious to a person of ordinary skill in
the art to promote catalyst activity by removing water from gas exiting the
reducing apparatus and recycling the dewatered gas.

Obviousness of Claim 10
Takahama discloses a reduction time that overlaps but is broader than
the time range recited claim 10.
Takahama discloses a reduction time of about 0.5 to 60 hours, but this
time can be adjusted depending upon the temperature, atmosphere, and the
apparatus employed. Takahama ¶ 62.
Given that Takahama teaches a reducing time that overlaps that of
claim 10, it would have been prima facie obvious to a person of ordinary
skill in the art to reduce the unreacted catalyst over the claimed time period
by optimizing the reduction time depending upon the temperature,
atmosphere, and the apparatus employed.

Obviousness of Claim 11
Takahama reduces the calcined catalyst precursor until 75 to 93
percent of the cobalt atoms are reduced. Takahama ¶ 69.

Obviousness of Claim 12
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Takahama teaches silica carrier precursors having a specific surface
area of 50 to 500 m2/g and a mesopore volume of 0.35 to 0.8 cm3/g.
Takahama ¶¶ 36, 31.

Obviousness of Claim 13
Takahama discloses silica, silica-alumina, and titania as suitable
carriers for the carrier precursor. Takahama ¶ 42.

Accordingly, a preponderance of the evidence supports a
determination of obvious of claims 1–3 and 5–13 based upon the
combination of Takahama and Inga.

CONCLUSION
The Examiner’s rejection is reversed with designated new grounds of
rejection. We enter a new ground rejection of claims 1–3 and 5–13 under §
103 as being unpatentable over the combination of Takahama and Inga
pursuant to 37 C.F.R. § 41.50(b).
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DECISION SUMMARY
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed New
Ground
1–3, 5–
13
103 Van De
Loosdrecht, Inga,
Takahama
1–3, 5–
13

1–3, 5–
13
103 Takahama, Inga 1–3, 5–
13
Overall
Outcome
1–3, 5–
13
1–3, 5–
13

TIME PERIOD FOR RESPONSE
This decision contains a new ground of rejection pursuant to 37
C.F.R. § 41.50(b). 37 C.F.R. § 41.50(b) provides that “[a] new ground of
rejection pursuant to this paragraph shall not be considered final for judicial
review.”
37 C.F.R. § 41.50(b) also provides that the Appellant, within two months
from the date of the decision, must exercise one of the following two options
with respect to the new ground of rejection to avoid termination of the
appeal as to the rejected claims:

(1) Reopen prosecution. Submit an appropriate amendment of the claims
so rejected or new Evidence relating to the claims so rejected, or
both, and have the matter reconsidered by the examiner, in which
event the prosecution will be remanded to the examiner…

(2) Request rehearing. Request that the proceeding be reheard under §
41.52 by the Board upon the same Record…

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Further guidance on responding to a new ground of rejection can be found in
the Manual of Patent Examining Procedure § 1214.01.

REVERSED; NEW GROUND 37 C.F.R. § 41.50(b)