Ex Parte Eng

Patent Trial and Appeal Board

Oct 31, 2013

11927828 (P.T.A.B. Oct. 31, 2013)

UNITED STATES PATENT AND TRADEMARKOFFICE
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 11/01/2013
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
11/01/2013 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 APPEAL

Appeal 2012-007957
Application 11/927,828

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A. STATEMENT OF THE CASE
The Appellant has filed an appeal under 35 U.S.C. § 134 from an
Examiner’s decision finally rejecting claims 1-12 and 23-42. We have jurisdiction
under 35 U.S.C. § 6(b).
We REVERSE and enter new grounds of rejection.
The subject matter on appeal is directed to a process for producing olefins
from hydrocarbon mixtures containing one or more butanes comprising, inter alia,
the step of bypassing a first product around an existing etherification reactor for
converting isobutylene to methyl tert-butyl ether (MTBE).
According to the Appellant’s Specification:
MTBE production has decreased as various jurisdictions restricted or
banned its use. By late 2006 most American gasoline retailers
stopped using MTBE as an oxygenate. Accordingly, domestic
production has continued to decline. As a result, MTBE
manufacturers are left holding useless feedstocks and manufacturing
assets.
There is a need, therefore, for reallocating feedstocks and
manufacturing assets previously allocated to the manufacture of
MTBE, thereby providing an economic benefit to MTBE
manufacturers.
Spec., ¶¶ [0003]-[0004].
The Appellant’s process reallocates MTBE feedstocks and manufacturing
assets to produce olefins such as propylene. Spec., ¶ [0012].
Representative claim 1 is reproduced below from the Claims Appendix of
the Appeal Brief dated January 17, 2012 (“App. Br.”).
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1. A process for producing one or more olefins, comprising:
[1] dehydrogenating a feed comprising one or more C4-
containing compounds to provide a first product comprising about 20
vol% to about 80 vol% isobutylene;
[2] bypassing the first product comprising about 20 vol% to
about 80 vol% isobutylene around an existing etherification reactor
for converting isobutylene to methyl tert-butyl ether; and
[3] cracking at least a portion of the first product comprising
about 20 vol% to about 80 vol% isobutylene to provide a second
product comprising propylene, ethylene, and butane.
Claims 1-12 and 23-42 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Hensley (U.S. 5,254,748 issued Oct. 19, 1993) in view of Vora
(U.S. 6,049,017 issued Apr. 11, 2000) and Tsunoda (U.S. 6,307,117 B1 issued Oct.
23, 2001). The Appellant presents separate arguments for claims 1, 2, 5, 32, 33,
and 38 in the Appeal Brief.
B. EXAMINER’S REJECTION UNDER 35 U.S.C. § 103(a)
The Examiner finds Hensley discloses a process for producing isoolefins
comprising, inter alia, dehydrogenating a feed comprising one or more C4-
containing compounds to provide a first product which bypasses a MTBE reactor.
Ans. 4-5.1 The Examiner relies on Tsunoda and Vora as teaching the production of
ethylene, propylene, and butane in an olefin cracking process. Id. at 5. The
Examiner concludes it would have been obvious to one of ordinary skill in the art
to introduce an olefin cracking step in Hensley to produce ethylene and propylene
“[s]ince ethylene and propylene are important raw materials for a variety of
products.” Id. at 5-6.

1 Examiner’s Answer dated February 24, 2012.
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Contrary to the Examiner’s findings, Hensley does not disclose that the first
product bypasses a MTBE reactor. Rather, Hensley discloses that “[a]n essential
feature of all the disclosed embodiments of the present invention is directed to
integrating a combination hydrogenation/dehydrogenation step . . . into an
etherification process.” Hensley, col. 3, ll. 24-28; see also App. Br. 10. Thus,
absent the Appellant’s disclosure, there would have been no reason to bypass the
first product around a MTBE reactor in Hensley’s process and introduce an olefin
cracking step as proposed by the Examiner.2 For this reason, the § 103(a) rejection
is not sustained.
C. 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 paragraphs [0003] and [0004] of the Appellant’s Specification.
1. 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; 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 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,

2 The Examiner also concludes that it would have been obvious “to modify Vora
invention and take the C4+ stream directly to the cracking step as disclosed by
Tsunoda when MTBE is not a required product.” Ans. 6. To the extent that the
Examiner is proposing that the claims on appeal are also unpatentable under
§ 103(a) based on Vora in view of Tsunoda, the Examiner has failed to
demonstrate that the dehydrogenating step recited in claim 1 is rendered obvious
by the combination of Vora and Tsunoda.
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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/de-hydrogenation 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.
The reaction product from the hydrogenation/dehydrogenation unit of
Hensley is substantially the same as the hydrocarbon feedstock used in the method
of Tsunoda. 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.
As for step [2] of the claimed process, Hensley discloses that the reaction
product from the hydrogenation/dehydrogenation unit 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.
The Appellant discloses that MTBE production was on the decline at the
time of the Appellant’s invention and “MTBE manufacturers are left holding
useless feedstocks and manufacturing assets.” Spec., ¶ [0003]. Thus, according to
the Appellant, “[t]here is 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].
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Based on this disclosure in the Appellant’s Specification, we find one of
ordinary skill in the art would have been motivated to reallocate Hensley’s MTBE
feedstocks and manufacturing assets (i.e., Hensley’s hydrogenation/de-
hydrogenation unit) 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). Thus, we conclude the process recited in claim 1 is
rendered obvious by the combination of Tsunoda, Hensley, and paragraphs [0003]
and [0004] of the Appellant’s Specification.
2. Claim 2
Claim 2 depends from claim 1 and recites the following additional steps:
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., 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.
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3. 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.,
Claims App’x.
Hensley discloses that the reaction temperature in the hydrogenation/de-
hydrogenation 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 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.
4. 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
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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.
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, paragraphs [0003]
and [0004] of the Appellant’s Specification, 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% butane.” However, claim 38 includes
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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., 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 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

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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, [are] unexpectedly good”). Thus, the weight of
the evidence supports a conclusion of obviousness under 35 U.S.C. § 103(a).
D. DECISION
The Examiner’s rejection of claims 1-12 and 23-42 under 35 U.S.C. § 103(a)
as unpatentable over Hensley in view of Vora and Tsunoda is reversed.
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 paragraphs [0003]
and [0004] of the Appellant’s Specification.
Claim 38 is rejected 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.
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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).

REVERSED
(37 C.F.R. § 41.50(b))

bar