DETAILED ACTION
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 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.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 21-24 are rejected on the ground of nonstatutory double patenting as being unpatentable over claim 17 of U.S. Patent No. 12253024 in view of Allam 20180073434 (hereinafter Allam434).
Claim 17 of the Patent teaches at least all the limitations of claims 21-24, except for the recycled stream being a recycle CO2 stream.
However, it was known that combustion of (e.g. hydrocarbon) fuel produces CO2 in the exhaust, such that recycled exhaust streams of recuperative heat exchange systems are also recycled CO2 streams, as explained by Allam434 ([0065]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the recycle flow of exhaust in claim 12 of the Patent 12253024 contained (or could contain) CO2 as taught by Allam434 for increased efficiency (Allam434, Abstract).
Claim 25 is rejected on the ground of nonstatutory double patenting as being unpatentable over claim 5 of U.S. Patent No. 12253024 in view of Allam 20180073434 (hereinafter Allam434).
Claim 5 of the Patent teaches at least all the limitations of claim 25, except for providing the streams separately to the combustor.
However, Allam434 teaches providing recycle CO2 and oxidant streams to the combustor separately in order to control the individual flow rates and flow conditions thereof ([0066-68]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to supply the flows of claim 5 of the Patent 12253024 to the combustor separately as taught by Allam434 in order to control the individual flow rates and flow conditions thereof ([0066-68]).
Priority
Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged. Applicant has not complied with one or more conditions for receiving the benefit of an earlier filing date under 35 U.S.C. 120 as follows:
The later-filed application must be an application for a patent for an invention which is also disclosed in the prior application (the parent or original nonprovisional application or provisional application). The disclosure of the invention in the parent application and in the later-filed application must be sufficient to comply with the requirements of 35 U.S.C. 112(a) or the first paragraph of pre-AIA 35 U.S.C. 112, except for the best mode requirement. See Transco Products, Inc. v. Performance Contracting, Inc., 38 F.3d 551, 32 USPQ2d 1077 (Fed. Cir. 1994).
The disclosure of the prior-filed application, Application No. 17/321212, fails to provide adequate support or enablement in the manner provided by 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph for claims 27, 29, 31, 35, and 39 (and thus, dependent claims 30-34 and 36-40) because the prior-filed application does not disclose
Cl.27, 32, 35-36: “the recuperative heat exchanger system is configured to add cold[/hot] gas to the cooling flow” (emphasis added); Specification only states “[i]n order to match the required turbine coolant temperature, hot gas or cold gas may be added to the cooling flow to raise or lower the temperature to match the required turbine coolant temperature“ in [0027], which is not sufficient support for the underlined portion of the claim above. The Drawings do not depict a cold/hot gas (see also Drawing objection and 112a rejection below)
Cl.29, 39: “the cooling flow…[provided as a] separate strea[m] to the combustor”; Specification only states (in [0021, 27]) “It is further envisioned that a series of manifolds within the recycle and heat recovery sections may be used to redistribute the recycled high-pressure carbon dioxide and to provide draw points for the various turbine cooling flows that may be required…Additionally, a second flow line 304 may be used to provide the turbine with a cooling flow. In a non-limiting example, the cooling flow may be a recycle gas leaving 107a or 301b. In some cases, a temperature of the cooling flow may not match a required turbine coolant temperature. In order to match the required turbine coolant temperature, hot gas or cold gas may be added to the cooling flow to raise or lower the temperature to match the required turbine coolant temperature. In some embodiments, the cooling flow may be a blended mixture from the recycle stream leaving 107a or 301b and the higher temperature recycle stream leaving 301a.” This is not sufficient support for providing the cooling flow to the combustor as a separate stream. The Drawings do not depict the cooling flow (304) provided to the combustor, nor it being provided separately from other streams (see also Drawing objection and 112a rejection below).
Thus, claims 27, 29-40 are interpreted with the effective filing date of the current Application, 11 February 2025.
Drawings
The drawings filed 15 October 2025 present new matter (placing 305 in 105 downstream of certain flow splits and junctions) and are not entered.
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the following must be shown or the feature(s) canceled from the claim(s). No new matter should be entered.
Cl.27, 32, 35-36: “the recuperative heat exchanger system is configured to add cold[/hot] gas to the cooling flow”; drawings do not show cold/hot gas, or the recuperative heat exchanger system supplying the cold/hot gas (see also 112a rejection below)
Cl.29, 39: “the cooling flow…[provided as a] separate strea[m] to the combustor”; drawings do not show cooling flow (304) provided to the combustor, nor it being provided separately from other streams (see also 112a rejection below)
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Specification
Amendments to the Specification filed 15 October 2025 refer to the Drawing amendments filed 15 October 2025, which are not entered, thus the Specification amendments are not entered.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 27 and 29-40 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Regarding claims 27, 29, 32, 35, and 39, the following limitations are not provided sufficient written description in the original disclosure:
Cl.27, 32, 35-36: “the recuperative heat exchanger system is configured to add cold[/hot] gas to the cooling flow”
Cl.29, 39: “the cooling flow…[provided as a] separate strea[m] to the combustor”
MPEP2163.03(V) provides that while there is a presumption that an adequate written description of the claimed invention is present in the specification as filed, a question as to whether a specification provides an adequate written description may arise in the context of an original claim when (1) the claim defines the invention in functional language specifying a desired result but the disclosure fails to sufficiently identify how the function is performed or the result is achieved or (2) a broad genus claim is presented but the disclosure only describes a narrow species with no evidence that the genus is contemplated.
In this case, the above claim limitations are functional recitations (per MPEP2173.05(g)) of desired results of the system (i.e. using the recuperative heat exchange system to add cold gas to the cooling flow, providing the cooling flow as a separate stream to the combustor, and using heated recycle CO2 to cool exhaust gases in the precooler). However, the disclosure does not provide sufficient description of how to perform the claimed functions.
Regarding the cold/hot gas, [0027] states: “[i]n order to match the required turbine coolant temperature, hot gas or cold gas may be added to the cooling flow to raise or lower the temperature to match the required turbine coolant temperature” and the Drawings do not depict any cold/hot gas. This disclosure does not explain what cold/hot gas would have been used under what conditions or using what structures, with sufficient detail to provide 112a support.
Regarding the cooling flow, [0021 and 27] state “It is further envisioned that a series of manifolds within the recycle and heat recovery sections may be used to redistribute the recycled high-pressure carbon dioxide and to provide draw points for the various turbine cooling flows that may be required…Additionally, a second flow line 304 may be used to provide the turbine with a cooling flow. In a non-limiting example, the cooling flow may be a recycle gas leaving 107a or 301b. In some cases, a temperature of the cooling flow may not match a required turbine coolant temperature. In order to match the required turbine coolant temperature, hot gas or cold gas may be added to the cooling flow to raise or lower the temperature to match the required turbine coolant temperature. In some embodiments, the cooling flow may be a blended mixture from the recycle stream leaving 107a or 301b and the higher temperature recycle stream leaving 301a.” The Drawings do not show any cooling gas being provided to any combustor. This disclosure does not explain under what conditions or using what structures, the cooling flow would have been provided to the combustor, with sufficient detail to provide 112a support.
Thus, claims 27, 29, 32, 35-36, and 39 are rejected under 112a for lack of written description.
Further regarding claim 39, “wherein combustor is a component of the turbine” is not idiomatic English (unclear whether applicant intended to recite “a combustor” or “the combustor”).
Dependent claims 30-34 and 36-40 are also rejected for relying on at least one rejected claim above.
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.
Claims 29-30, 32-34 is/are rejected under 35 U.S.C. 103 as being unpatentable over Allam434 in view of Conlon, Allam 10018115 (hereinafter Allam115), and Takahashi 20100229566.
Regarding claim 29, Allam434 teaches a system (Fig 3), comprising:
a turbine (incl. 30, 31) including a combustor (30); and
a recuperative heat exchanger system (incl. 29, 27, 26, 58), wherein the recuperative heat exchanger system is configured to receive exhaust gases (55) from the turbine, and the recuperative heat exchanger system includes:
at least one precool section (29) configured to receive and to cool the exhaust gases from the turbine and output a flow of cooled exhaust gases (66);
a minor heat exchange section (58) configured to cool a portion (46) of the flow of cooled exhaust gases;
a major heat exchange section (potions of 26, 27) configured to cool a further portion (51, 52) of the flow of cooled exhaust gases against a recycle CO2 stream (50) to form a heated recycle CO2 stream (54); and
at least one heat recovery section (where 42 passes through part of 26, 27 to produce 43), wherein the at least one heat recovery section is configured to provide a fluid flow (43) that bypasses the minor heat exchange section and the major heat exchange section (43 does not pass into 58, 26, 27), and
wherein an oxidant stream (41) and the heated recycle CO2 stream from the major heat exchange section are provided as separate streams to the combustor (Fig 3).
Allam434 further teaches the minor heating section includes a water separating heat exchange portion (line 46 through 58), and the heat recovery section involves transferring heat from a compressed airflow of the air separation plant (81) to the major heat exchange section as a low level heat source.
Allam434 does not teach the minor heat exchange section cooling the exhaust gases against an oxidant stream to form a heated oxidant stream that is the oxidant stream provided to the combustor, the fluid flow of the heat recovery section being a cooling flow to the turbine, and the cooling flow being provided as another separate stream to the combustor.
However, Conlon teaches a water separating heat exchanger (140 in Figs 1-5; col.7 ll.59-end) cooling an exhaust gas from a turbine (260, 150) that may be an oxidant heating section (col.7 ll.59-end; Figs 1-5) to produce a heated oxidant used for combustion (in 160).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the minor heating section (including water separating heat exchanger) of Allam434 to be an oxidant heating section as taught by Conlon, in order to make use of liquefied oxidant while efficiently using waste heat to regasify the oxidant and condense water vapor from the exhaust (Conlon, Figs 1-5, col.7 ll.59-end).
Allam434 in view of Conlon still does not teach the fluid flow of the heat recovery section being a cooling flow to the turbine, and the cooling flow being provided as another separate stream to the combustor.
However, Allam115 teaches that the low level heating provided to the recuperative heat exchanger(s) from an external source such as the compressor section of an air separating process, may alternatively be provided by steam (col.5 ll.45-47, col.6 ll.12-24).
And, Takahashi teaches using steam (205) from a boiler (160) as a cooling fluid that is provide to a turbine (112) for cooling (via 41, 42) and provided to a combustor (2), separately from the air and fuel provided to the combustor (Fig 6), in order to an improvement in gas turbine efficiency ([0074]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Allam434 in view of Conlon to use steam as the fluid flow as taught by Allam115 and Takahashi, because Allam115 teaches the substitutional equivalence of using steam and using compressed air of an air separation unit as the heat source for a recuperating heat exchange section of a gas turbine engine system (col.5 ll.45-47, col.6 ll.12-24) and because Takahashi teaches the steam usage improves efficiency and lowers turbine manufacturing costs ([0073-75]).
Regarding claim 30, Allam434 in view of Conlon, Allam115, and Takahashi teaches all the limitations of the claimed invention as discussed above. Allam434 further teaches the at least one precool section is configured to receive and to cool all of the exhaust gases from the turbine (Fig 3).
Regarding claim 32, Allam434 in view of Conlon, Allam115, and Takahashi teaches all the limitations of the claimed invention as discussed above (including the cooling flow being the flow 42, 43 in Allam434; and the flow 205 in Takahashi). Allam434 in view of Conlon, Allam115, and Takahashi as discussed so far, does not teach the recuperative heat exchanger system is configured to add cold gas to the cooling flow.
However, Takahashi further teaches the steam (205) from the boiler (160) being provided as the cooling fluid that to the turbine (112) for cooling (via 41, 42), along with cold gas (204, which is cold relative to the hot turbine components) added to the cooling flow (Fig 6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Allam434 (in view of Conlon, Allam115, and Takahashi) to use steam (and cold gas) as the fluid flow as taught by Takahashi, because Takahashi teaches the steam usage improves efficiency and lowers turbine manufacturing costs ([0073-75]).
Regarding claim 33, Allam434 in view of Conlon, Allam115, and Takahashi teaches all the limitations of the claimed invention as discussed above (including stream 60 of Allam434 being a heated oxidant stream as modified by Conlon). Allam434 further teaches a temperature of the heated oxidant stream is different than a temperature of the heated recycle C02 stream (the heated recycle CO2 stream being any of 50 downstream of 26, 27, or 29; which are all at different temperatures, at least one of the heated recycle CO2 streams is at a different temperature than stream 60).
Regarding claim 34, Allam434 in view of Conlon, Allam115, and Takahashi teaches all the limitations of the claimed invention as discussed above. Allam434 further teaches the number of heat exchangers in the major heat exchange section (26, 27 being two heat exchangers) is greater than the number of heat exchangers in the minor heat exchange section (58 being a single heat exchanger).
Claims 35-37 is/are rejected under 35 U.S.C. 103 as being unpatentable over Allam434 in view of Allam115 and Takahashi.
Regarding claim 35, a system (Fig 3), comprising:
a turbine (31); and
a recuperative heat exchanger system (incl. 29, 27, 26, 58), wherein the recuperative heat exchanger system is configured to receive exhaust gases (55) from the turbine, and the recuperative heat exchanger system includes:
at least one precool section (29);
a major heat exchange section (portions of 26, 27);
a minor heat exchange section (58); and
at least one heat recovery section (where 42 passes through part of 26, 27 to produce 43), wherein the at least one heat recovery section is configured to provide a fluid flow (43) that bypasses the minor heat exchange section and the major heat exchange section (43 does not pass through any of 26, 27, 58).
Allam434 further teaches the heat recovery section involves transferring heat from a compressed airflow of the air separation plant (81) to the major heat exchange section.
Allm434 does not teach providing the fluid flow as a cooling flow to the turbine, and the recuperative heat exchanger system is configured to add cold gas to the cooling flow.
However, Allam115 teaches that the low level heating provided to the recuperative heat exchanger(s) from an external source such as the compressor section of an air separating process, may alternatively be provided by steam (col.5 ll.45-47, col.6 ll.12-24).
And, Takahashi teaches using steam (205) from a boiler (160) as a cooling fluid that is provided to a turbine (112) for cooling (via 41, 42), along with cold gas (204, which is cold relative to the hot turbine components) added to the cooling flow (Fig 6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Allam434 to use steam (and cold gas) as the fluid flow as taught by Allam115 and Takahashi, because Allam115 teaches the substitutional equivalence of using steam and using compressed air of an air separation unit as the heat source for a recuperating heat exchange section of a gas turbine engine system (col.5 ll.45-47, col.6 ll.12-24) and because Takahashi teaches the steam usage improves efficiency and lowers turbine manufacturing costs ([0073-75]).
Regarding claim 36, Allam434 in view of Allam115 and Takahashi teaches all the limitations of the claimed invention as discussed above (including the cooling flow being the flow 42, 43 in Allam434; and the flow 205 in Takahashi). Allam434 in view of Allam115 and Takahashi as discussed so far, does not teach the at least one heat recovery section is configured to add hot gas to the cooling flow.
However, Takahashi further teaches the steam (205) from the boiler (160) being provided as the cooling fluid that to the turbine (112) for cooling (via 41, 42), along with hot gas (204 is hot relative to ambient temperature) added to the cooling flow (Fig 6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Allam434 (in view of Allam115, and Takahashi) to use steam (and cold gas) as the fluid flow as taught by Takahashi, because Takahashi teaches the steam usage improves efficiency and lowers turbine manufacturing costs ([0073-75]).
Regarding claim 37, Allam434 in view of Allam115 and Takahashi teaches all the limitations of the claimed invention as discussed above. Allam434 further teaches the at least one precool section is configured to receive and to cool all of the exhaust gases from the turbine (Fig 3) against an oxidant stream from the minor heat exchange section (stream 46 combines with stream 42 via 53, 21, 23, 22 as stream 69, which becomes stream 49 via 24 and 67; and [0069] teaches adding oxygen to the stream 49 such that the stream 50 passing through the precool section 29 is an oxidant stream against which the exhaust gases from the turbine are cooled).
Claims 38-40 is/are rejected under 35 U.S.C. 103 as being unpatentable over Allam434 in view of Allam115 and Takahashi, and in further view of Conlon.
Regarding claim 38, Allam434 in view of Allam115 and Takahashi teaches all the limitations of the claimed invention as discussed above. Allam434 further teaches the minor heat exchange section is configured to cool a portion (46) of a flow of cooled exhaust gases (66) from the at least one precool section, and
wherein the major heat exchange section is configured to cool a further portion (51, 52) of the flow of cooled exhaust gases against a recycle CO2 stream (50) to form a heated recycle CO2 stream (54).
Allam434 further teaches the minor heating section includes a water separating heat exchange portion (line 46 through 58).
Allam434 in view of Allam115 and Takahashi does not teach the minor heat exchange section cooling the exhaust gases against an oxidant stream to form a heated oxidant stream.
However, Conlon teaches a water separating heat exchanger (140 in Figs 1-5; col.7 ll.59-end) cooling an exhaust gas from a turbine (260, 150) that may be an oxidant heating section (col.7 ll.59-end; Figs 1-5) to produce a heated oxidant used for combustion (in 160).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the minor heating section (including water separating heat exchanger) of Allam434 (in view of West) to be an oxidant heating section as taught by Conlon, in order to make use of liquefied oxidant while efficiently using waste heat to regasify the oxidant and condense water vapor from the exhaust (Conlon, Figs 1-5, col.7 ll.59-end).
Regarding claim 39, Allam434 in view of Allam115, Takahashi, and Conlon teaches all the limitations of the claimed invention as discussed above. Allam434 further teaches the turbine may include a combustor (turbine being the combination of 30, 31; interpreted under 112b discussion above), and the recuperative heat exchanger system is configured to provide the heated oxidant stream and the heated recycle CO2 stream as separate streams to the combustor (Fig 3).
Allam434 in view of Allam115, Takahashi, and Conlon as discussed so far, does not teach also providing the cooling flow as a separate stream to the combustor.
However, Takahashi further teaches providing the steam cooling flow (205) to a combustor (2), separately from the air and fuel provided to the combustor (Fig 6), in order to an improvement in gas turbine efficiency ([0074]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Allam434 in view of Allam115, Takahashi, and Conlon to use steam in the combustor as taught by Takahashi, because Takahashi teaches the steam usage improves efficiency and lowers turbine manufacturing costs ([0073-75]).
Regarding claim 40, Allam434 in view of Allam115, Takahashi, and Conlon teaches all the limitations of the claimed invention as discussed above (including stream 60 of Allam434 being a heated oxidant stream as modified by Conlon). Allam434 further teaches a temperature of the heated oxidant stream is different than a temperature of the heated recycle C02 stream (the heated recycle CO2 stream being any of 50 downstream of 26, 27, or 29; which are all at different temperatures, at least one of the heated recycle CO2 streams is at a different temperature than stream 60).
Claim Objections
Claims 26-28 are objected to as being dependent upon a rejected base claim, but may be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Response to Arguments
Applicant's arguments filed 15 October 2025 have been fully considered but they are not persuasive.
Applicant argues that because the disclosure regarding adding the cold gas is with respect to features of a recuperative heat exchanger system shown in Fig 2, “it follows that one of skill in the art would readily appreciate that the recuperative heat exchanger system is configured to add the cold gas to the cooling flow within the recuperative system”.
However, mere discussion of adding a cold gas to the cooling flow in the same paragraph as discussion of elements in Fig 2 is not sufficient to require that the cold gas limited to being added to the cooling flow within the system of 105 (dashed box) in Fig 2. For example, the same paragraph [0027] also mentions the turbine, which is not considered part of the recuperative system per the claim construction of cl.27, 32, 35-36 (and the claims on which they depend).
Applicant argues that amending the combustor to be part of the turbine overcomes the priority issues with claims 29 and 39.
However, such amendment still provides the combustor as a component of the turbine, such that providing the cooling flow to the combustor is more specific than providing the cooling flow to the turbine, and this specificity was not supported by the prior filed application. The amendment further does not resolve the issue of providing the cooling flow as a separate stream to the combustor (of the turbine).
Applicant argues that Applicants’ Drawings are schematic (common in the art) and the subject matter of the claims does not require specific structural or condition disclosure to be supported under 112a. For both the cold gas limitation and the cooling flow limitation, Applicant asserts that one of ordinary skill in the art who understands how to implement complex heat exchanger systems would understand how to route cold gas and cooling flow as claimed.
However, none of the arguments address how the original disclosure provides sufficient 112a written description support to show Applicant possessed the high specificity of the limitations of the claims.
For example, routing a cold gas, generally, is not an issue. However, the claim(s) require(s) (claim 27) “the recuperative heat exchanger system is configured to add cold gas to the cooling flow”, wherein (per claim 21, upon which claim 27 depends) the turbine and the combustor are not part of the recuperative heat exchange system (they are claimed as separate components). Thus the combination of limitations in the claims requires that cold gas be added to the cooling flow separately from the turbine and combustor, which is more specific than [0027] of the disclosure. It is unclear whether Applicant had considered (at the time of filing) specifically adding a cold gas to the cooling flow in the recuperative heat exchange system, rather than at the turbine or combustor because the Drawings and Specification do not provide sufficient explanation of the cold gas addition to show possession of the specificity of the functional language of the claim. For example, if claim 27 recited “The system of claim 26, wherein cold gas is added to the cooling flow”, this is a more generic claim, than the current claim.
Similarly regarding the cooling flow, routing the cooling flow in general is not an issue. And routing the cooling flow to the turbine is not an issue (see e.g. claim 26, which is not rejected under 112a). However, routing the cooling flow as a separate flow to the combustor in addition to routing the same cooling flow to the turbine is much more specific. Even if the combustor is recited as part of the turbine, routing cooling flow to the combustor portion of the turbine is more specific than routing the cooling flow to the turbine, in general. It is not clear from the Drawings and Specification that Applicant specifically considered and possessed a system where cooling flow (such as 304) is routed to the turbine, and then to the combustor without mixing with any other streams before being sent to the combustor. The only mention of cooling flows are in [0021, 27], and neither provides any explanation of cooling flow passing to the combustor either in parallel with the turbine or after the turbine, as a separate stream or combined with other streams. Routing the cooling flow through the turbine in a closed loop manner such that cooling flow is further routed to the combustor without being mixed with any other flow, is much more specific and complex than generally providing the cooling flow to the turbine.
Regarding claims 29 and 35, Applicant argues that “in Allam ‘434, the alleged heat recovery section flows through the heat exchangers 26, 27 that interpreted as the major section such that the air stream 42 does not bypass the heat exchangers 26, 27…[and] heat exchanger 58 is fed with a cooling water stream 59 that likewise does not bypass the heat exchanger 58”.
However, the claims recite: the “heat recovery section is configured to provide a cooling flow to the turbine that bypasses the minor heat exchange section and the major heat exchange section”. In Allam ‘434 the cooling flow is 43 (after exiting 26, 27), this flow “bypasses” all of the heat exchangers 26, 27, 58, by not passing through them. Allam ‘434 teaches that 42 may be a steam rather than air, such that 43 is also steam. Takahashi further does not teach passing a steam cooling flow through any recuperating heat exchangers before passing the steam to the turbine for cooling. Thus all the prior art teaches the cooling flow bypassing the major and minor heat exchange sections (by not passing through them).
Notes on Correspondence
A phone call to Applicant’s representative on 02 December 2025 to discuss the fact that no prior art rejections were likely to be made in the current Office Action, and to request whether Applicant would be interested in discussed amendments to take the case to allowance. The preliminary proposal involved cancelling claims 29-40, making amendments to dependent claims to address priority, Drawing, and 112a issues, and filing a terminal disclaimer to address the Double Patenting issue. Response was requested by 09 December 2025. Applicant’s representative consulted with Applicant and returned with informal proposed amendments on 10 December 2025 (attached herein but stamped do NOT enter). However, these informal proposed amendments did not immediately place the claims in condition for allowance (the scopes of claims 29 and 35 do not include all the features of claim 21 that was indicated as not being subject to prior art rejection during the phone call, the scopes of dependent claims 25-28, 32, 36-37, and 39-40 were changed significantly, and claim 41 was newly presented). Since a complete search and consideration of the formally filed claims and remarks from 15 October 2025 was already completed on 02 December 2025, the current Final Office Action is being mailed and Applicant may consider formally filing their informal proposed amendments in response to the current Office Action.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Correspondence
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/STEPHANIE SEBASCO CHENG/Primary Examiner, Art Unit 3741