Ex Parte Roberts et al

Patent Trial and Appeal Board

Jan 21, 2016

12435869 (P.T.A.B. Jan. 21, 2016)

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.
12/435,869 05/05/2009 Mark Julian Roberts 07319 USA 4258
23543 7590 01/21/2016
AIR PRODUCTS AND CHEMICALS, INC.
PATENT DEPARTMENT
7201 HAMILTON BOULEVARD
ALLENTOWN, PA 18195-1501
EXAMINER
CRENSHAW, HENRY T
ART UNIT PAPER NUMBER
3744
MAIL DATE DELIVERY MODE
01/21/2016 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 MARK JULIAN ROBERTS and
VISHAL ANANDSWARUP VARMA
____________

Appeal 2014-000335
Application 12/435,869
Technology Center 3700
____________

Before NINA L. MEDLOCK, CYNTHIA L. MURPHY, and
BRADLEY B. BAYAT, Administrative Patent Judges.

MURPHY, Administrative Patent Judge.

DECISION ON APPEAL

The Appellants1 appeal under 35 U.S.C. § 134 from the Examiner’s
rejections of claims 1–13 and 16–18.2 We have jurisdiction over this appeal
under 35 U.S.C. § 6(b).

We AFFIRM.

1 “The real party in interest in the above-identified application is Air
Products and Chemicals, Inc.” (Appeal Br. 3.)
2 “Claims 14 and 15 are withdrawn and claims 19 and 20 are cancelled.”
(Final Action 2.)
Appeal 2014-000335
Application 12/435,869

2
STATEMENT OF THE CASE
The Appellants’ invention “provid[es] an improved liquefaction
system and method that utilizes a hydrofluorocarbon (HFC) to precool a
natural gas feed stream prior to liquefying the pre-cooled feed using a mixed
refrigerant.” (Spec. ¶ 13.)

Illustrative Claim3
1. A method for liquefying a natural gas stream using two
refrigerants, the method comprising the steps of:
providing a dehydrated natural gas stream for
liquefaction;
pre-cooling the dehydrated natural gas stream in a pre-
cooling apparatus, wherein the pre-cooling is performed by
using a pre-coolant refrigerant that consists essentially of a
hydroflorocarbon (HFC) refrigerant;
further cooling the pre-cooled dehydrated natural gas
stream in a main heat exchanger through indirect heat exchange
against a vaporized hydrocarbon mixed refrigerant coolant to
produce a liquefied natural gas product stream,
wherein the mixed refrigerant coolant comprises ethane,
methane, nitrogen, and less than or equal to 3 mol % of propane
or heavier hydrocarbons.

References
Gaumer US 3,763,658 Oct. 9, 1973
Chiu US 4,548,629 Oct. 22, 1985
Vertens US 5,406,784 Apr. 18, 1995
Eaton US 6,722,157 B1 Apr. 20, 2004
Jones US 2004/0134196 A1 July 15, 2004
Roberts US 2005/0056051 A1 Mar. 17, 2005

3 This illustrative claim is quoted from the Claims Appendix (“Claims
App.”) set forth on pages 15–18 of the Appeal Brief.
Appeal 2014-000335
Application 12/435,869

3
Rejections
The Examiner rejects claims 1–8, 10–12, and 16–18 under 35 U.S.C.
§ 103(a) as unpatentable over Gaumer, Eaton, Roberts, and Chiu. (Final
Action 3.)
The Examiner rejects claim 9 under 35 U.S.C. § 103(a) as unpatentable
over Gaumer, Eaton, Roberts, Chiu, Jones, and Vertens. (Id. at 11.)
The Examiner rejects claim 13 under 35 U.S.C. § 103(a) as
unpatentable over Gaumer, Eaton, Roberts, Chiu, and Jones. (Id. at 12.)

ANALYSIS
Independent claim 1 is directed to “[a] method for liquefying a natural
gas stream using two refrigerants” namely a “pre-coolant refrigerant” and a
“mixed refrigerant.” (Claim App.) Independent claim 10 is directed to a
system for doing the same. (Id.) The Examiner finds Gaumer teaches a
system, and thus a method, for liquefying a natural gas stream using a
single-component refrigerant in a pre-cooling apparatus 34 and using a
multi-component (i.e., mixed) refrigerant in a main heat exchanger 50. (See
Final Action 3, 8; see also Gaumer col. 2:56–59, col. 3:17–22.)
Independent claim 1 requires the pre-coolant refrigerant to “consist[]
essentially of a hydroflorocarbon (HFC) refrigerant,” and independent
claim 10 recites “a HFC refrigerant.” (Claims App.) Gaumer discloses that
its pre-cooling apparatus 34 uses “propane” or “other single component
refrigerant.” (Gaumer col. 3:43–44.) The Examiner determines that it
would have been obvious, in view of the teachings of Eaton and Roberts, to
replace Gaumer’s “single component refrigerant” with an HFC refrigerant.
(See Final Action 4, 8–9.)
Appeal 2014-000335
Application 12/435,869

4
Independent claim 1 also requires the mixed refrigerant to comprise
“less than or equal to 3 mol % of propane,” and independent claim 10 recites
the same limitation. (Claims App.) Gaumer discloses that the multi-
component refrigerant used by its main heat exchanger 50 comprises “0–19
mole percent of propane.” (Gaumer col. 4:61–64.) The Examiner
determines that it would have been obvious, in view of the teachings of
Eaton and Chiu, to eliminate propane from Gaumer’s multi-component
refrigerant. (See Final Action 5, 9.)
The Examiner’s determinations are based upon a finding that Eaton
“teaches the desirability of reducing the use of volatile refrigerants such as
propane due to safety issues.” (Final Action 4 (citing Eaton col. 2:5–15.))
As such, the Examiner determines that “a person of ordinary skill in the art
would be aware of the hazards associated with propane refrigerants,” and
“would be motivated to reduce the use of propane due to safety [reasons].”
(Answer 16–17, 19–20.) With respect to the pre-coolant refrigerant, the
Examiner finds Roberts teaches “that both [an HFC refrigerant] and propane
can be used for the same purpose in the same system.” (Id. at 17; see also
Roberts ¶ 110.)4 With respect to the mixed refrigerant, the Examiner finds
Chiu teaches using a mixed refrigerant without propane. (See Answer 19–
20; see also Chiu col. 5:53–61.)
The Appellants advance arguments premised upon the fact that
Gaumer focuses on using propane and touts the advantages (i.e., optimum
operating conditions) of doing so. (See e.g., Appeal Br. 8–9, 11–12.) We
are not persuaded by these arguments because they “do not address the

4 According to the Appellants, R134a is a “single component HFC
refrigerant[].” (Spec. ¶ 34.)
Appeal 2014-000335
Application 12/435,869

5
Eaton reference” (Answer 16) and the motivation it provides to reduce
propane for safety reasons.5
The Appellants also advance arguments premised upon the
Examiner’s proposed modifications resulting in significant and expensive
reductions in efficiency in Gaumer’s system. (See e.g., Appeal Br. 12–13;
Reply Br. 2–4.) We are not persuaded by these arguments because “[w]hile
changing refrigerants may negatively impact efficiency, whether or not to
put the primary emphasis on safety or efficiency is a matter of choice.”
(Answer 18.) Also, the fact that a “combination would not be made by
businessmen for economic reasons does not mean that a person of ordinary
skill in the art would not make the combination because of some
technological incompatibility.” In re Farrenkopf, 713 F.2d 714, 718 (Fed.
Cir. 1983).
The Appellants further argue that “a person of ordinary skill in the art
[would find Gaumer] ‘non-enabling with respect to using refrigerants other
than those containing propane’” and “would[] be led away from using such
refrigerants.” (Appeal Br. 11.) However, the Appellants do not allege that
Gaumer’s system cannot function with reduced propane, only “that it will
not function as well as it does with propane.” (Answer 20.) Also, the

5 The Appellants argue that the Eaton does not contain an “express
teaching” regarding reducing the amount of propane in the “mixed
refrigerant loop.” (Reply Br. 6.) This argument appears to be raised for the
first time in the Reply Brief (see Appeal Br. 10–13) and not in response to a
new issue raised by the Examiner (see Answer 19–21.) “Any argument
raised in the reply brief which was not raised in the appeal brief, or is not
responsive to an argument raised in the examiner's answer . . . will not be
considered by the Board for purposes of the present appeal, unless good
cause is shown.” 37 C.F.R. § 41.41(b)(2)(2007).
Appeal 2014-000335
Application 12/435,869

6
Appellants do not point, with particularity, to statements in Gaumer
criticizing, discrediting, or otherwise discouraging the reduction of propane
should safety take precedence over efficiency.
With respect to Roberts, the Appellants argue that it teaches the use of
propane in a refrigerant circuit in that a mixed refrigerant is “composed of
8.45% propane.” (Appeal Br. 10, (citing Roberts ¶ 155).) We are not
persuaded by this argument because it “does not address the safety
motivation” taught by Eaton and it does not dispute “the fact that Roberts
also teaches the use of [an HFC refrigerant] in lieu of propane.”
(Answer 18.)
With respect to Chiu, the Appellants argue that its discussion of
“thermodynamic efficiency” relates only “to a very specific system design”
and does not teach “that reductions in propane in a refrigerant mixture will
categorically increase thermodynamic efficiency of a cooling system.”
(Appeal Br. 11–12; see also Reply Br. 5.) We are not persuaded by this
argument because “the safety motivation” taught by Eaton “would still be
present.” (Answer 21.)
Also with respect to Chiu, the Appellants argue it characterizes “the
use of the four component refrigerant as a necessity” for Gaumer’s system,
and “not merely a matter of choice on sacrificing efficiency for safety.”
(Reply Br. 6.) We are not persuaded by this argument because, as noted by
the Appellants (see Appeal Br. 5), Chiu teaches that modifications can be
built into a natural-gas-liquefying system to accommodate a mixed
refrigerant without propane (see Chiu col. 5:55–col. 6:8). And the Examiner
can “take account of the inferences and creative steps that a person of
Appeal 2014-000335
Application 12/435,869

7
ordinary skill in the art would employ.” KSR Int'l Co. v. Teleflex Inc.,
550 U.S. 398, 417 (2007).
Accordingly, we are not persuaded by the Appellants’ position that
the method of independent claim 1 and the system of independent claim 10
would not have been obvious over Gaumer, Eaton, Roberts, and Chiu. Thus,
we sustain the Examiner’s rejection of independent claims 1 and 10.
The Appellants do not further argue dependent claims 2–8, 11, 12, and
16–18. (See Appeal Br. 13.) As for claims 9 and 13, the Appellants argue
only that Vertens and Jones do not compensate for the above-discussed
deficiencies in Gaumer, Eaton, Roberts, and Chiu. (Id. at 13–14.) Thus, we
also sustain the Examiner’s rejections of dependent claims 2–9, 11–13,
and 16–18.

DECISION
We AFFIRM the Examiner’s rejections of claims 1–13 and 16–18.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED

rvb