Ex Parte Merrill

Patent Trial and Appeal Board

Mar 30, 2015

12177740 (P.T.A.B. Mar. 30, 2015)

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.
12/177,740 07/22/2008 James T. Merrill COS-1151 4997
25264 7590 03/30/2015
FINA TECHNOLOGY INC
PO BOX 674412
HOUSTON, TX 77267-4412
EXAMINER
BULLOCK, IN SUK C
ART UNIT PAPER NUMBER
1772
MAIL DATE DELIVERY MODE
03/30/2015 PAPER
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.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte JAMES T. MERRILL
____________

Appeal 2013-002770
Application 12/177,740
Technology Center 1700
____________

Before JEFFREY T. SMITH, KAREN M. HASTINGS, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.

SMITH, Administrative Patent Judge.

DECISION ON APPEAL

STATEMENT OF THE CASE

This is an appeal under 35 U.S.C. § 134 from a final rejection of
claims 1, 4 through 11, 14 through 18 and 21 through 23. We have
jurisdiction under 35 U.S.C. § 6.
Appellant’s invention is generally directed to methods for the
production of isoprene. Br. 6–9. Claim 1 is illustrative of the subject matter
on appeal and is reproduced below:
1. A method for the production of isoprene comprising:

contacting a hydrocarbon feedstock containing
isoamylene with a dehydrogenation catalyst, at a pressure of
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Application 12/177,740

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1,000 mbar or less, under reaction conditions effective to
dehydrogenate at least a portion of said isoamylene to produce
isoprene;

supplying steam to the dehydrogenation reaction in a
steam to hydrocarbon molar ratio of at least 10: 1; and

operating the dehydrogenation reaction in a reactor at a
temperature of at least 300°C;

wherein the reactor temperature increase from catalyst
deactivation averages no more than 1°C per day for at least 45
consecutive days of operation; and

wherein the reaction can operate in excess of 45 days
before the catalyst is a deactivated catalyst.

The Examiner relied on the following references in rejecting the
appealed subject matter:
Ripley US 3,725,494 Apr. 3, 1973
Kowaleski US 2006/0106267 Al May 18, 2006

Kh. Kh. Gil’manov, et al., "Effect of the Paste Molding Pressure on
the Activity of Iron Oxide Catalyst in Dehydrogenation of Methylbutenes" in
79 RUSSIAN JOURNAL OF APPLIED CHEMISTRY, (9), 1447–1452 (2006).
1

David R. Lide, et al., CRC Handbook of Chemistry and Physics, 91ST
EDITION, 2011 INTERNET EDITION, D.R. LIDE, ED.

Appellant (see Brief, generally) requests review of the following
rejections from the Examiner’s Final Office Action:
I. Claims 1, 4–11, 14–18, and 21 rejected under 35 U.S.C.
§ 103(a) as unpatentable over Gil’manov and Kowaleski.

1
We will identify this reference as “Gil’manov”.
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II. Claim 22 rejected under 35 U.S.C. § 103(a) as unpatentable
over Gil’manov, Kowaleski and Lide.
III. Claim 23 rejected under 35 U.S.C. § 103(a) as unpatentable
over Gil’manov, Kowaleski, Lide and Ripley.

OPINION
Prior Art Rejections under 35 U.S.C. § 103(a)

Claims 1, 4–11, 14–18, 21 and 22 (Rejections I and II)
The dispositive issue on appeal for this rejection is: Did the Examiner
err in determining that the combined teachings of Gil’manov and Kowaleski
would have led one skilled in the art to a method for the production of
isoprene from a hydrocarbon feedstock containing isoamylene comprising
the steps of contacting the hydrocarbon feed with a catalyst at a pressure
below atmospheric pressure and supplying steam to dehydrogenate the
isoamylene at a steam to hydrocarbon ratio of at least 10:1 as required by the
subject matter of independent claims 1, 15 and 22?
2, 3

2
Appellant relies on the same arguments in addressing independent claims 1
and 15 and dependent claims 6, 8, and 21. Brief 11–15, 20. Appellant does
not present separate arguments for dependent claims 4, 5, 7, 9–11, 14, and
16–18. See Brief, generally. We limit our discussion to independent claim
1 but will address arguments directed to specific claims where necessary.
However, dependent claims 4, 5, 7, 9–11, 14, and 16–18 stand or fall with
their respective independent claim.
3
Independent claim 22 is directed to a method for the production of isoprene
similar to independent claim 15 but further requires the hydrocarbon to be in
vapor phase. The Examiner relied on the additional reference to Lide to
establish that the hydrocarbons in Gil’manov’s process are in vapor phase.
Final Act. 20. Appellant’s arguments addressing Lide essentially state that
Lide does not overcome alleged deficiencies of the combined teachings of
Gil’manov and Kowaleski. Br. 23–24. Thus, a discussion of Lide is not
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After review of the respective positions provided by Appellant and the
Examiner, we AFFIRM for the reasons presented by the Examiner.
Independent claims 1, 15 and 22 are directed to a method for the
production of isoprene from a hydrocarbon feedstock containing isoamylene
by contacting the isoamylene hydrocarbon feed with a catalyst at a pressure
of below atmospheric pressure (1,000 mbar or less for independent claims 1
and 22; 850 mbar or less for independent claim 15) and supplying steam to
dehydrogenate the isoamylene hydrocarbon feed at a steam to hydrocarbon
ratio of at least 10:1.

The Examiner found Gil’manov discloses a process for
dehydrogenating isoamylenes to produce isoprene by contacting an
isoamylene hydrocarbon feed with a dehydrogenation catalyst in a
dehydrogenation reactor at a pressure of 1 atm., i.e., 1,013 mbar and a steam
to hydrocarbon molar ratio of 20:1 that falls in the claimed steam to
hydrocarbon molar ratio of 10:1 or more. Final Act 3–4; Gil’manov 1147–
1448. The Examiner found Gil’manov does not disclose operating at a
pressure of 1,000 mbar or less, increasing the reactor temperature an average
of no more than 1 °C per day for at least 45 consecutive days of operation
due to catalyst deactivation or operating the reaction in excess of 45 days
before the catalyst is deactivated. Final Act. 4–5. The Examiner found
Kowaleski discloses a process for dehydrogenating an isoamylene
hydrocarbon feed with an iron oxide catalyst by contacting the isoamylene
hydrocarbon feed with a dehydrogenation catalyst in a dehydrogenation

necessary for disposition of Rejection II. Accordingly, we treat Rejections I
and II together with the understanding that our discussion of Rejection I
applies to Rejection II.
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reactor at pressures ranging from vacuum (0 mbar) to about 2,000 mbar.
Final Act. 4–5; Kowaleski ¶ 55. The Examiner also found Kowaleski
discloses operating the hydrogenation process by increasing the temperature
in the reactor to maintain constant conversion of the hydrocarbon feed to a
dehydrogenated product. Final Act. 4; Kowaleski ¶ 68. The Examiner
found it would have been prima facie obvious to modify the
dehydrogenation process of Gil’manov and reduce the pressure of the
reaction as taught by Kowaleski because it would involve the application of
a known operating technique to improve a known dehydrogenation process
to yield predictable results. Final Act. 5; Kowaleski ¶ 55.
Appellant argues the Examiner is relying on impermissible hindsight
in combining the references because Gil’manov teaches away from a
dehydrogenation process at pressures of 1,000 mbar or less. Br. 16, 18–19.
Appellant further argues Kowaleski is directed to the production of styrene
from ethylbenzene and does not disclose a process for dehydrogenation of
non-aromatic alkenes even with the passing reference of dehydrogenation of
isoamylene to form isoprene. Id. at 16–17.
We are unpersuaded by these arguments and agree with the
Examiner’s determination of obviousness. Final Act. 3–18. While
Appellant argues that Gil’manov teaches away from pressures lower than
1,000 mbar (Br. 16), Appellant has not pointed to portions of Gil’manov that
support this argument. Further, the Examiner relied on Kowaleski to address
a dehydrogenation process operated at pressures of 1,000 mbar or less. As
noted by the Examiner, Kowaleski discloses that the dehydrogenation
process can be conducted at pressures of vacuum (0 mbar) to 2,000 mbar,
which overlaps the claimed range of 1,000 mbar or less. Final Act. 4–5;
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Kowaleski ¶ 55. Furthermore, the lower end of Kowalski’s range of 1013
mbar is so close to Appellant’s upper end of the range of 1000 mbar that it
supports a determination of obviousness.
4
As also noted by the Examiner,
Kowaleski is not limited to the production of styrene from ethylbenzene but
is directed to dehydrogenation of a number of hydrocarbon feedstocks,
including an isoamylene hydrocarbon feedstock for the production of
isoprene. Final Act. 4; Kowaleski ¶ 53. Thus, the Examiner has established
a reasonable basis to conclude that the claimed invention would have been
obvious over the prior art cited. Final Act. 3–6. Appellant has not presented
arguments or analysis that establishes error in the Examiner’s obviousness
rejection. Appellant has not adequately explained why one skilled in the art
would not expect Gil’manov’s dehydrogenation of isoamylene hydrocarbon
feedstock to result in the production of isoprene given Kowaleski’s teaching.
Appellant argues Kowaleski teaches away from the claimed steam to
oil ratio of at least 10:1. Br. 17.
We are also unpersuaded by this argument. The Examiner relied on
Gil’manov’s disclosure of a steam to oil ratio of 20:1 to address the claimed
steam to oil ratio of at least 10:1. Final Act. 4; Gil’manov 1447. While
Kowaleski discloses using lower steam to oil ratios (Kowaleski ¶ 23),
Appellant has not pointed to portions of Kowaleski that would have led one

4
See, In re Peterson, 315 F.3d 1325, 1329 (Fed. Cir. 2003) (“even a slight
overlap in range establishes a prima facie case of obviousness” and “a prima
facie case of obviousness exists when the claimed range and the prior art
range do not overlap but are close enough such that one skilled in the art
would have expected them to have the same properties”) . Titanium Metals
Corp. v. Banner, 778 F.2d 775, 783 (Fed. Cir. 1985).

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skilled in the art to understand that the disclosed pressure operating
conditions are associated exclusively with Kowaleski’s steam to oil ratios.
Appellant argues the cited art does not teach the claimed reactor
temperature increase per day over 45 days and operating the reactor in
excess of 45 days and that such is not inherent in the cited art. Br. 18–19.
According to Appellant, Kowaleski covers only 35 days of continuous
operation of a dehydrogenation process of ethylbenzene to styrene, a process
different from the one claimed. Br. 20.
We are unpersuaded by these arguments as well. As noted by the
Examiner, Kowaleski discloses adjusting the reactor temperature daily to
maintain a stable conversion of a hydrocarbon feed to a dehydrogenated
product. Final Act. 4; Kowaleski ¶ 68. The Examiner found the data over
25 days in Kowaleski’s Figures 1–4 shows an average increase in
temperature reactor of less than 1
o
C per day to maintain a desired rate of
conversion of hydrocarbon feed to a dehydrogenated product. Ans. 29. One
skilled in the art would be capable of determining how long to continue a
dehydrogenation process before a catalyst deactivates. See In re Sovish, 769
F.2d 738, 743 (Fed. Cir. 1985) (skill is presumed on the part of one of
ordinary skill in the art); In re Bozek, 416 F.2d 1385, 1390 (CCPA 1969).
Appellant has not adequately explained why one skilled in the art would not
have been capable of determining how to maximize a dehydrogenation
process before a catalyst deactivates given the disclosure of Kowaleski.
With respect to independent claims 15 and 22, Appellant argues
Kowaleski does not disclose a dehydrogenation catalyst having an average
effective pore diameter of at least 500 nm. Br. 17.
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We are unpersuaded by this argument and note that the Examiner
found Gil’manov teaches the claimed dehydrogenating catalyst. Final Act.
3, 14; Gil’manov Fig 1a. Appellant has not disputed this finding by the
Examiner. See Brief, generally.
Accordingly, we affirm the Examiner’s prior art rejections of claims
1, 4–11, 14–18, 21, and 22 under 35 U.S.C. § 103(a) (Rejections I and II).

Claim 23 (Rejection III)
After review of the respective positions provided by Appellant and the
Examiner, we AFFIRM for the reasons presented by the Examiner.
Dependent claim 23 the hydrocarbon feedstock for the
dehydrogenation process to comprise at least 95 wt. % isoamylene.
The Examiner relied on Ripley to teach as known the use a
hydrocarbon feed comprised of pure (100%) isoamylene in a
dehydrogenation process to produce isoprene. Final Act. 22; Ripley col. 6,
ll. 9–18.
Appellant argues Ripley uses a dehydrogenation catalyst comprising
amounts of potassium carbonate outside the potassium carbonate amount
disclosed for Appellant’s catalyst and the cited art does not teach claimed
percent of isoamylene feed. Br. 26; Spec. ¶ 10.
We are unpersuaded by these arguments. As noted by the Examiner,
claim 23 does not require any specific potassium carbonate content. Ans.
30–31. Moreover, Appellant has not adequately explained why Ripley’s
disclosure of pure isoamylene (2-methylbutene-2) does not suggest to one
skilled in the art to use a feed comprising at least 95 wt. % isoamylene.
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Accordingly, we affirm the Examiner’s prior art rejection of claim 23
(Rejection III) for the reasons provided by the Examiner and given above.

ORDER
The Examiner’s prior art rejections of claims 1, 4–11, 14–18 and 21-
23 under 35 U.S.C. § 103(a) (Rejections I–III) are affirmed.

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

AFFIRMED
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