Ex Parte Eng

Patent Trial and Appeal Board

Jan 30, 2014

11927828 (P.T.A.B. Jan. 30, 2014)

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.
11/927,828 10/30/2007 Curtis N. Eng 07-01 6524
7590 01/30/2014
Christian N. Heausler
Kellogg Brown & Root LLC
601 Jefferson Avenue
Houston, TX 77002
EXAMINER
BULLOCK, IN SUK C
ART UNIT PAPER NUMBER
1772
MAIL DATE DELIVERY MODE
01/30/2014 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 CURTIS N. ENG
__________

Appeal 2012-007957
Application 11/927,828
Technology Center 1700
___________

Before ADRIENE LEPIANE HANLON, GEORGE C. BEST, and
DONNA M. PRAISS, Administrative Patent Judges.

HANLON, Administrative Patent Judge.

DECISION ON REHEARING
The Appellant requests rehearing of a Decision on Appeal dated
November 1, 2013, entering the following new grounds of rejection:
(1) claims 1-12, 23-37, and 39-42 under 35 U.S.C. § 103(a) as
unpatentable over the combination of Tsunoda,1 Hensley,2 and paragraphs
[0003] and [0004] of the Appellant’s Specification; and

1 US 6,307,117 B1, issued Oct. 23, 2001.
2 US 5,254,748, issued Oct. 19, 1993.
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Application 11/927,828

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(2) claim 38 under 35 U.S.C. § 103(a) as unpatentable over the
combination of Tsunoda, Hensley, paragraphs [0003] and [0004] of the
Appellant’s Specification, and Vora.3
The Appellant argues the Board engaged in impermissible hindsight
by relying on the Appellant’s Specification in the new grounds of rejection.
Req. Reh’g 5.4
Upon consideration of the Appellant’s Request for Rehearing, the
Board has discovered that the designation “admitted prior art” was
inadvertently omitted in describing paragraphs [0003] and [0004] of the
Appellant’s Specification. The new grounds of rejection entered in the
Decision on Appeal dated November 1, 2013, are hereby withdrawn and
second new grounds of rejection are hereby entered. Thus, the Appellant’s
Request for Rehearing is granted-in-part.
NEW GROUNDS OF REJECTION
Claims 1-12, 23-37, and 39-42 are rejected under 35 U.S.C. § 103(a) as
unpatentable over the combination of Tsunoda, Hensley,
and the admitted prior art.5
Claim 1
There is no dispute on this record that Tsunoda discloses a method of
producing ethylene, propylene, and butane by cracking C4+ olefins. Ans. 5;6
see also Tsunoda, col. 12, ll. 14-15 (ethylene and propylene are collected
from the obtained H2-C3 fraction); Tsunoda, col. 12, ll. 38-48 (butane is

3 US 6,049,017, issued Apr. 11, 2000.
4 Request for Rehearing dated January 2, 2014.
5 Paragraphs [0002] through [0004] of the Appellant’s Specification entitled
“Description of the Related Art.”
6 Examiner’s Answer dated February 24, 2012.
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separated by the C4 separator). In one embodiment, Tsunoda discloses that
the hydrocarbon feedstock is a C4 fraction comprised mainly of C4
hydrocarbons, such as butane, isobutane, butene, and isobutene. Tsunoda,
col. 11, ll. 61-67. Thus, we find Tsunoda discloses step [3] of the claimed
process.
As for step [1] of the claimed process, Hensley discloses a method of
producing tertiary alkyl ether compounds, such as MTBE, from a mixture of
C4 hydrocarbons. Hensley, col. 4, ll. 51-55. According to one embodiment
of the invention, a mixed C4 hydrocarbon feed stream is provided to a
hydrogenation/dehydrogenation unit along with an isobutane stream from an
isomerization unit. Id. at col. 5, ll. 56-62. Hensley discloses that the
reaction product from the hydrogenation/dehydrogenation unit comprises
primarily isobutene but also contains significant amounts of butene-1,
butene-2, n-butane, and isobutane. Id. at col. 4, l. 67-col. 5, l. 2 and col. 5,
ll. 52-54. We find one of ordinary skill in the art would have understood
that a reaction product comprising “primarily isobutene” contains an amount
of isobutene within the claimed range of “about 20 vol% to about 80 vol%.”7
As for step [2] of the claimed process, Hensley does not disclose that
the reaction product from the hydrogenation/dehydrogenation unit bypasses
an existing etherification reactor. Rather, Hensley discloses that the reaction
product feeds a distillation column, and the overhead from the distillation
unit is fed to a MTBE unit. Id. at col. 5, l. 63-col. 6, l. 2.
Nonetheless, at the time of the Appellant’s invention, MTBE
production was known to be declining and “MTBE manufacturers [were]
left holding useless feedstocks and manufacturing assets.” Spec. ¶ [0003].

7 Isobutene is another name for isobutylene.
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Thus, at the time of the Appellant’s invention, “[t]here [was] a need . . . for
reallocating feedstocks and manufacturing assets previously allocated to the
manufacture of MTBE, thereby providing an economic benefit to MTBE
manufacturers.” Id. at ¶ [0004]. Based on this admitted prior art, we find
one of ordinary skill in the art would have been motivated to find another
use for Hensley’s MTBE feedstocks and manufacturing assets (i.e.,
Hensley’s hydrogenation/dehydrogenation unit).
The reaction product from the hydrogenation/dehydrogenation unit of
Hensley (i.e., primarily isobutene with significant amounts of butene-1,
butene-2, n-butane, and isobutane) is substantially the same as the
hydrocarbon feedstock in the method of Tsunoda (i.e., a C4 fraction
comprised mainly of C4 hydrocarbons, such as butane, isobutane, butene,
and isobutene). Thus, we find one of ordinary skill in the art would have
considered Hensley’s reaction product to be a suitable feedstock in
Tsunoda’s method and, based on the admitted prior art, would have
reallocated Hensley’s MTBE feedstocks and manufacturing assets to
produce the feedstock in Tsunoda’s method. This combination results in
step [2] of the claimed process (i.e., bypassing Hensley’s reaction product
from the hydrogenation/dehydrogenation unit around an existing
etherification reactor).
For the reasons set forth above, we conclude that the process recited
in claim 1 would have been obvious to one of ordinary skill in the art based
on the combined teachings of Tsunoda, Hensley, and the admitted prior art.
Claim 2
Claim 2 depends from claim 1 and recites the following additional
steps:
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selectively separating at least a portion of the second
product to provide a third product comprising propylene and a
first recycle comprising butane; and
recycling at least a portion of the first recycle to the first
product prior to cracking the first product.
App. Br. 14, Claims App’x.
The product obtained by cracking in Tsunoda’s method (i.e., second
product) contains propylene, ethylene, and butane. Tsunoda discloses that
the second product is selectively separated to provide a third product
comprising propylene and a first recycle comprising butane. Tsunoda
discloses that at least a portion of the first recycle is returned to the reactor
and used as part of the hydrocarbon feedstock in the cracking operation.
Tsunoda, col. 12, ll. 1-22, 32-48. Thus, Tsunoda discloses the process steps
recited in claim 2.
Claim 5
Claim 5 depends from claim 1 and recites that “the first product is
heated to a temperature from 90ºC to 370ºC prior to cracking the first
product.” App. Br. 15, Claims App’x.
Hensley discloses that the reaction temperature in the
hydrogenation/dehydrogenation unit is in the range of from about 600º F. to
about 1100º F. (i.e., from about 315º C. to about 593º C.). Hensley, col. 4,
ll. 31-37. Thus, prior to cracking, the modified Tsunoda process heats the
first product to a temperature that overlaps the claimed range.
It is well-settled that “even a slight overlap in range establishes a
prima facie case of obviousness.” In re Peterson, 315 F.3d 1325, 1329 (Fed.
Cir. 2003). Thus, the burden shifts to the Appellant to “show that the
[claimed] range is critical, generally by showing that the claimed range
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achieves unexpected results relative to the prior art range.” In re Woodruff,
919 F.2d 1575, 1578 (Fed. Cir. 1990). The Appellant has not provided such
a showing on this record.
Claims 32 and 33
The Appellant argues Hensley does not “teach, show, or suggest the
feed comprises about 70% vol or more isobutane (claim 32) or about 70%
vol or more isobutane and about 5% vol to about 30% vol n-butane [(claim
33)].” App. Br. 12.
Referring to the feeds in Hensley’s Examples 1 and 2, the Appellant
argues the “isobutane and n-butane concentrations are far below the claimed
ranges.” Id; see also Hensley, col. 8, ll. 50-60 (feed contains 1.56% by
weight n-butane); Hensley, col. 9, ll. 41-51 (feed contains 2.00% by weight
n-butane). However, “it is well established that the disclosure of a reference
is not limited to specific working examples contained therein.” In re
Fracalossi, 681 F.2d 792, 794 n.1 (CCPA 1982).
We find Hensley teaches the concentration of isobutane in the feed
stream is a result effective variable. Hensley, col. 4, ll. 51-59; see also In re
Boesch, 617 F.2d 272, 276 (CCPA 1980) (“discovery of an optimum value
of a result effective variable in a known process is ordinarily within the skill
of the art”). Thus, the burden shifts to the Appellant to demonstrate that a
feed comprising “about 70% vol or more isobutane” achieves unexpectedly
good results. See In re Antonie, 559 F.2d 618, 620 (CCPA 1977) (a prima
facie case of obviousness may be rebutted “where the results of optimizing a
variable, which was known to be result effective, [are] unexpectedly good”).
The Appellant has not made such a showing on this record.
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As for the concentration of n-butane recited in claim 33, we find the
feeds employed by the Appellant and Hensley are both used for
manufacturing MTBE. Thus, it is reasonable to expect that the feeds would
have similar n-butane concentrations. In this regard, we note the Appellant
does not disclose that the n-butane concentration is critical and indicates that
as little as about 1% vol butane may be contained in the feedstock. Spec.
¶ [0019].
Based on the foregoing, the weight of the evidence supports a
conclusion of obviousness under § 103(a).
Claim 38 is rejected under 35 U.S.C. § 103(a) as unpatentable
over the combination of Tsunoda, Hensley,
the Admitted Prior Art, and Vora.
As in claim 33, claim 38 recites “the feed contains about 70% vol or
more isobutane and about 5% vol to about 30% vol butane.” However,
claim 38 includes the additional limitation that “the first recycle comprises
about 5% vol to about 20% vol isobutane and about 20% vol to about 80%
vol butane.” App. Br. 18, Claims App’x.
The Examiner relies on Vora as evidence that the claimed
concentration of isobutane and butane in the first recycle would have been
obvious to one of ordinary skill in the art. Ans. 10. However, the Appellant
argues “Vora simply makes no mention or suggestion as to the claimed
composition.” App. Br. 13.
The Examiner recognizes that Vora does not expressly disclose the
claimed concentration of isobutane and butane in the first recycle. Ans. 10.
However, Vora, like Tsunoda, employs a cracking reaction zone to produce
ethylene and propylene. See, e.g., Vora, col. 4, ll. 40-47. The Examiner
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finds Vora discloses that preventing buildup of paraffins, such as isobutane,
in the feed to the cracking reaction zone is necessary. Ans. 10; Vora, col. 9,
ll. 54-55. Thus, the Examiner concludes it would have been obvious to one
of ordinary skill in the art to “use a recycle with the percentage of butane
and isobutane in an appropriate rage [sic, range], including as claimed to
prevent buildup of isobutene [sic, isobutane].” Ans. 10. The Appellant has
not directed us to any error in the Examiner’s position.
Moreover, Tsunoda discloses:
In the recycle system, butane contained in the
hydrocarbon feedstock is concentrated in the C4 fraction
separated by means of the above-mentioned C4 separator. For
this reason, if all of the C4 fraction is recycled to the reactor, the
butane concentration of the hydrocarbon feedstock charged into
the reactor would become high, so that the concentration of at
least one olefin having 4 to 12 carbons in the hydrocarbon
feedstock may become unsatisfactory. Therefore, it is preferred
that only a part of the C4 fraction is recycled to the reactor so as
to suppress the increase in the butane concentration of the
feedstock.
Tsunoda, col. 12, ll. 38-48.
Based on the foregoing, we find Vora and Tsunoda teach that the
concentrations of isobutane and butane in the first recycle are result-
effective variables. See Boesch, 617 F.2d at 276 (“discovery of an optimum
value of a result effective variable in a known process is ordinarily within
the skill of the art”). The Appellant has not directed us to any evidence
demonstrating that a first recycle comprising the claimed concentrations of
isobutane and butane achieves unexpectedly good results. See Antonie, 559
F.2d at 620 (a prima facie case of obviousness may be rebutted “where the
results of optimizing a variable, which was known to be result effective,
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[are] unexpectedly good”). Thus, the weight of the evidence supports a
conclusion of obviousness under 35 U.S.C. § 103(a).
DECISION
Claims 1-12, 23-37, and 39-42 are rejected under 35 U.S.C. § 103(a)
as unpatentable over the combination of Tsunoda, Hensley, and the admitted
prior art.
Claim 38 is rejected under 35 U.S.C. § 103(a) as unpatentable over
the combination of Tsunoda, Hensley, the admitted prior art, and Vora.
This decision contains new grounds of rejection under 37 C.F.R.
§ 41.50(b) which provides that “[a] new ground of rejection . . . 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 grounds 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 proceeding
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. . . .
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).

GRANTED-IN-PART
(37 C.F.R. § 41.50(b))

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