Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-10, in the reply filed on 09/18/25 is acknowledged.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1-10 are rejected under 35 U.S.C. 103 as being unpatentable over Applicant’s Admitted Prior Art (hereinafter AAPA) in view of Lourenco et al (US 20200386475; hereinafter Lourenco).
As regarding claim 1, AAPA discloses the claimed invention for a cooling loop comprises at least one compressor (fig. 1).
AAPA does not disclose an expander directly or indirectly supplies at least a portion of an amount of power needed to operate the at least one compressor. Lourenco teaches an expander directly or indirectly supplies at least a portion of an amount of power needed to operate the at least one compressor [[0035] – “Gas expander (26) generates shaft work, which may be connected to a power generator to produce electricity or to a prime mover”}. It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention was made to provide an expander directly or indirectly supplies at least a portion of an amount of power needed to operate the at least one compressor as taught by Lourenco in order to increase energy efficiency, reduce external power requirements, recover useful work form gas expansion, and lower both operational and environmental costs.
AAPA as modified discloses a method for chilling a natural gas stream, comprising: introducing a natural gas stream to the expander (Lourenco - 48 of fig. 3); obtaining an expanded natural gas stream from an outlet of the expander, the expanded natural gas stream having a lower temperature and a lower pressure than does the natural gas stream; introducing at least a portion of the expanded natural gas stream to a heat exchanger (Lourenco - 15, 17 of fig. 3), the heat exchanger promoting indirect thermal communication between the expanded natural gas stream or a portion thereof and an external refrigerant circulating through the heat exchanger by way of a cooling loop (fig. 1); wherein the cooling loop comprises at least one compressor; obtaining a chilled natural gas stream from an outlet of the heat exchanger; introducing the chilled natural gas stream to a cold separator (144); and obtaining from the cold separator a further chilled natural gas stream as an overhead stream and a first condensed liquid stream as a bottoms stream.
As regarding claim 2, AAPA as modified discloses all of limitations as set forth above. AAPA as modified discloses the claimed invention for wherein the expanded natural gas stream passes through a warm separator (Lourenco - 37 of fig. 3) before being introduced to the heat exchanger Lourenco - 15, 17 of fig. 3, an overhead stream from the warm separator being introduced to the heat exchanger as a precooled natural gas stream.
As regarding claim 3, AAPA as modified discloses all of limitations as set forth above. AAPA as modified discloses the claimed invention for wherein a bottoms stream comprising a second condensed liquid stream (Lourenco - 38 of fig. 3) is obtained from the warm separator.
As regarding claim 4, AAPA as modified discloses all of limitations as set forth above. AAPA as modified discloses the claimed invention except for wherein the second condensed liquid stream is combined with the first condensed liquid stream downstream from the cold separator. It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention was made to provide wherein the second condensed liquid stream is combined with the first condensed liquid stream downstream from the cold separator in order to enhance system performance, since it was known in the art as shown Sun et al (US 20180119034; hereinafter Sun; warm separator 135, cold separator 150 of fig. 3).
As regarding claim 5, AAPA as modified discloses all of limitations as set forth above. AAPA as modified discloses the claimed invention for wherein, following a startup period, the expander supplies sufficient power to operate the at least one compressor in the cooling loop without using an external power source (Lourenco – [0035]: utilizing the expander to supply the compressor’s power inherently reduces dependence on external power, particularly during brief operating periods).
As regarding claim 6, AAPA as modified discloses all of limitations as set forth above. AAPA as modified discloses the claimed invention for wherein the cooling loop further comprises a cooling loop separator upstream from the at least one compressor, and a condenser and a surge tank downstream from the at least one compressor, the at least one compressor receiving vaporized external refrigerant from the cooling loop separator and the surge tank receiving liquefied external refrigerant from the condenser (fig. 1).
As regarding claims 7-9, AAPA as modified discloses all of limitations as set forth above. AAPA as modified discloses the claimed invention except for wherein the natural gas stream has a temperature ranging from about 80oF to about 100oF (26.7oC to 37.8oC and a pressure ranging from about 400 psi to about 800 psi (2.67 MPa to 5.52MPa); wherein the expanded natural gas stream has a temperature ranging from about 75oF to about 90oF (23.9oC to 32.2oC) and a pressure ranging from about 350 psi to about 750 psi (2.41 MPa to 5.17 MPa); and wherein the chilled natural gas stream has a temperature ranging from about 60oF to about 75oF (15.6oC to 23.9oC). It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention was made to provide wherein the natural gas stream has a temperature ranging from about 80oF to about 100oF (26.7oC to 37.8oC and a pressure ranging from about 400 psi to about 800 psi (2.67 MPa to 5.52MPa); wherein the expanded natural gas stream has a temperature ranging from about 75oF to about 90oF (23.9oC to 32.2oC) and a pressure ranging from about 350 psi to about 750 psi (2.41 MPa to 5.17 MPa); and wherein the chilled natural gas stream has a temperature ranging from about 60oF to about 75oF (15.6oC to 23.9oC) in order to enhance system performance, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233.
As regarding claim 10, AAPA as modified discloses all of limitations as set forth above. AAPA as modified discloses the claimed invention except for wherein the expander is operatively coupled to the at least one compressor by a shaft. It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention was made to provide wherein the expander is operatively coupled to the at least one compressor by a shaft in order to allows direct mechanical energy transfer, improve system efficiency, recover expansion energy, reduce external power needs and simplify the overall system design, since it was known in the art as shown Golubev (US 20180347900; [0017]).
Conclusion
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/DUNG H BUI/ Primary Examiner, Art Unit 1773