DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
This is in response to Applicant’s arguments and amendments filed on 01/12/2026 amending Claims 2, 9, 19, and 20. Claims 1 - 20 are examined.
Drawings
The drawings were received on 01/12/2026. Replacement Figs. 1, 2, and 4 - 8 are acceptable. New Figs. 3A and 3B are NOT acceptable.
New Figs. 3A and 3B were received on 01/12/2026. These drawings are unacceptable because they contain NEW MATTER. The drawing details of the gas flow lines shown in New Figs. 3A and 3B were not shown in the drawings of provisional application 63/523,108 nor in any of the original drawings filed on 06/25/2024. The drawing details of the gas flow lines shown in New Fig. 3A appear to be different from the gas flow lines shown in original Fig. 3 filed on 06/25/2024. The drawing details of the gas flow lines shown in New Fig. 3B were not shown in any of the original drawings. Furthermore, the original Specification filed on 06/25/2024 failed to mention reference character “26” in Fig. 3B.
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 “…said relaxation zone comprises at least one internal gas flow recirculation path” must be shown or the feature(s) canceled from Claim 7. The original figures do not show “at least one internal gas flow recirculation path” in said relaxation zone. No new matter should be entered.
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
The amendment filed 01/12/2026 is objected to under 35 U.S.C. 132(a) because it introduces new matter into the disclosure. 35 U.S.C. 132(a) states that no amendment shall introduce new matter into the disclosure of the invention. The added material which is not supported by the original disclosure is as follows:
NEW Paragraph [0021] FIG. 3B is a cross sectional view of an illustrative embodiment of the fuel combustor of the present disclosure showing a portion of the rich fuel primary combustion stage showing flow trajectories and gas flow recirculation paths.
Refer to the Drawing Objection above for a discussion of how New Fig. 3B is new matter.
Applicant is required to cancel the new matter in the reply to this Office Action.
Duplicate Claim, Warning
Applicant is advised that should Claim 12 be found allowable, Claim 13 will be objected to under 37 CFR 1.75 as being a substantial duplicate thereof. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 608.01(m). Claim 12 recites “wherein the ammonia fuel and the combustion air are not mixed prior to entering the rich fuel combustion stage”. Claim 13 recites “wherein the ammonia fuel is mixed with the combustion air in the rich fuel combustion stage”. If the ammonia fuel and the combustion air are not mixed prior to entering the rich fuel combustion stage, then the ammonia fuel has to be mixed with the combustion air in the rich fuel combustion stage for combustion to take place within the rich fuel combustion stage. Therefore, Claims 12 and 13 are using different words to cover the same thing.
Claim Objections
Claims 19 and 20 are objected to because of the following informalities:
Claim 19, l. 2 “rich fuel primary combustion stage” is believed to in error for --rich fuel primary combustion [[stage]] zone-- because Claim 1, l. 2 recites “rich fuel primary combustion zone”.
Claim 20, l. 2 “rich fuel primary combustion stage” is believed to in error for --rich fuel primary combustion [[stage]] zone-- because Claim 1, l. 2 recites “rich fuel primary combustion zone”.
Appropriate correction is required.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1 – 3, 8 – 11, and 17 - 19 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Selim (2023/0313995A1).
Regarding Claim 1, Selim discloses, in Figs. 1 - 3, all the claimed limitations including a fuel combustor (17 – Fig. 2) for a nitrogen-containing fuel (ammonia – Para. [0035]) comprising: a rich fuel (Para. [0038]) primary combustion zone (56, 62 – Para. [0037]); a NOx relaxation zone (58, 64) downstream from said fuel rich primary combustion zone (56, 62 – Paras. [0037] and [0040]); a combustion reaction quench zone (labeled, Para. [0050]) downstream from said relaxation zone (58, 64); and a secondary lean fuel combustion zone (labeled, Para. [0050] “…an abundance of oxidant or air may be added quench the reaction, control the temperature, and burn the remaining fuel…”) downstream from said combustion reaction quench zone (labeled).
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Re Claim 2, Selim discloses the invention as claimed and as discussed above, including wherein the NOx relaxation zone (58, 64) comprises conduit (40 - Para. [0036] “…as shown in FIG. 3, the second length 64 may be longer than the first length 62 and the second length 64.”) to provide a residence time (any amount of time, Para. [0066] “…the combustion gases 34, the unburned ammonia, and the NOx produced from the first zone 56 may travel together through the second zone 58 over a long period of time with insufficient oxidants, which advantageously promotes the consumption of NOx, thereby reducing the emissions.”).
Re Claim 3, Selim discloses the invention as claimed and as discussed above, including wherein the NOx relaxation zone (58, 64) comprises a chemical reactor (Fig. 4, Para. [0049] “…ammonia to break down according to the arrows 402. This advantageously promotes the consumption of NOx in the second zone 58 while simultaneously producing hydrogen as a byproduct”. In other words, chemical reactions occurred in the NOx relaxation/second zone).
Re Claim 8, Selim discloses the invention as claimed and as discussed above, including a combustion turbine (10 – Fig. 1) comprising a turbine (18) and at least one fuel combustor (16, 17) of Claim 1.
Regarding Claim 9, Selim discloses, in Figs. 1 – 3 and Para. [0030], all the claimed limitations including a method of combustion of nitrogen-containing fuel (ammonia – Para. [0035]) comprising: - delivering a nitrogen-containing fuel (ammonia – Para. [0035]) to a rich fuel (Para. [0038]) combustion zone (56, 62 – Para. [0037]) of a fuel combustor (17 – Fig. 2); - at least partially combusting (Paras. [0037] and [0048]) the nitrogen-containing fuel in a rich fuel combustion stage (region inside the rich fuel combustion zone) in the rich fuel combustion zone (56, 62) of the combustor (17) to form a rich fuel combustion product mixture (34 and 101, Para. [0037] “The combustion gases (which include NOx) and the unburned fuel 101 travel together through the first zone 56 and into the second zone 58”.), wherein the rich fuel combustion product mixture comprises NO (NOx is a broad category that includes NO., Para. [0037]) at levels above equilibrium levels (In a chemical reaction, the "equilibrium level" referred to the state where the forward and reverse reaction rates are equal, resulting in constant concentrations of reactants and products. In other words, the concentration of NOx would be constant at chemical equilibrium because the rate of NOx formation would be equal to the rate on NOx decomposition.); - permitting NO levels formed during the rich fuel combustion stage in the rich fuel combustion zone of the combustor to relax (Para. [0049] “This advantageously promotes the consumption of NOx in the second zone 58 while simultaneously producing hydrogen as a byproduct.” and Para. [0066] “…the combustion gases 34, the unburned ammonia, and the NOx produced from the first zone 56 may travel together through the second zone 58 over a long period of time with insufficient oxidants, which advantageously promotes the consumption of NOx, thereby reducing the emissions.”) toward an equilibrium level in a relaxation zone (58, 64) of the fuel combustor (17); - following a relaxation stage, delivering additional combustion air to the combustion product mixture in a quench zone (labeled in Fig. 3 marked up above, Para. [0050] “…an abundance of oxidant or air may be added quench the reaction, control the temperature, and burn the remaining fuel…”) of the fuel combustor (17); - delivering the mixture of the rich fuel combustion product mixture and additional combustion air to a lean fuel combustion zone (labeled in Fig. 3 marked up above); and - further combusting (Para. [0050] “…an abundance of oxidant or air may be added quench the reaction, control the temperature, and burn the remaining fuel…”)) the rich fuel combustion product mixture in a lean fuel combustion stage in the lean fuel combustion zone (labeled in Fig. 3 marked up above).
Re Claim 10, Selim discloses the invention as claimed and as discussed above, including wherein the nitrogen-containing fuel is ammonia fuel (ammonia – Para. [0035]).
Re Claim 11, Selim discloses the invention as claimed and as discussed above, including wherein the ammonia fuel and the combustion air are mixed prior (Para. [0009] “The combustor further includes at least one fuel nozzle that is configured to inject a mixture of fuel and a first portion of oxidant in the first zone.” and Para. [0034] “The inlet 41 of the combustion chamber 42 may receive a mixture of fuel 100 and a first portion of oxidant or air 102 (e.g., from the at least one fuel nozzles 61 shown in FIG. 2)”) to entering the rich fuel combustion stage (56, 62).
Re Claim 17, Selim discloses the invention as claimed and as discussed above, including a method of power generation (Para. [0030]) comprising: - combusting a nitrogen-containing fuel (ammonia – Para. [0035]) in the fuel combustor (16, 17) of Claim 1 to produce a combustion exhaust gas (34); - exhausting the combustion exhaust gas (34) from the fuel combustor (17 – Fig. 3, outlet 45); and - driving a turbine (18) with the combustion exhaust gas (Para. [0030]).
Re Claim 18, Selim discloses the invention as claimed and as discussed above, including wherein the nitrogen-containing fuel is ammonia fuel (ammonia – Para. [0035]).
Re Claim 19, Selim discloses the invention as claimed and as discussed above, including wherein the ammonia fuel (ammonia – Para. [0035]) and the combustion air are mixed prior (Para. [0009] “The combustor further includes at least one fuel nozzle that is configured to inject a mixture of fuel and a first portion of oxidant in the first zone.” and Para. [0034] “The inlet 41 of the combustion chamber 42 may receive a mixture of fuel 100 and a first portion of oxidant or air 102 (e.g., from the at least one fuel nozzles 61 shown in FIG. 2)”) to entering the rich fuel primary combustion stage (interpreted as the “rich fuel primary combustion zone (56, 62)”).
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.
Claims 4 - 6 are rejected under 35 U.S.C. 103 as being unpatentable over Selim (2023/0313995A1) in view of Shaw et al. (4,285,193) in view of Yoshimura et al. (2016/0136616A1).
Re Claim 4 - 6, Selim teaches the invention as claimed and as discussed above. Selim teaches a fuel combustor for a nitrogen-containing fuel, i.e., base device, upon which the claimed invention can be seen as an improvement. Selim is silent on (Claim 4) wherein the chemical reactor comprises a catalytically enhanced chemical reactor, (Claim 5) wherein said catalytically enhanced chemical reactor comprises a honeycomb catalyst support, plate-type catalyst support, or corrugated-type catalyst support with catalyst carried by said support, and (Claim 6) wherein said catalyst is selected from one or more of metal oxide-based, zeolite-based, alkaline-earth metal-based, and rare-earth-based catalysts.
Shaw teaches, in Figs. 1 – 5 and Abstract, a similar gas turbine combustor (Title) having a rich fuel combustion stage (Fig. 1 labeled “Rich Primary Zone”) followed by a NOx relaxation zone (Fig. 1 – zones 4 and 5) downstream from said fuel rich primary combustion zone, wherein said NOx relaxation zone comprises a catalytically enhanced chemical reactor (Fig. 1 – zone 5 labeled “oxidation catalyst”). Shaw teaches, in the Abstract, “…utilizing catalytic oxidation with excess air to complete the combustion and minimize NOx formation”. Yoshimura teaches, in Figs. 1 – 7, Abstract, Para. [0002], Para. [0003], Para. [0054], and Para. [0116], a catalytically enhanced chemical reactor comprises a honeycomb catalyst support (100 – Fig. 4(a)) with catalyst carried by said support wherein said catalyst is selected from one or more of metal oxide-based (Para. [0003] ““TiO2/V2O5/WO3 catalyst” in which vanadium oxide and tungsten oxide are supported on titanium oxide”).
Thus, improving a particular device (fuel combustor for a nitrogen-containing fuel), based upon the teachings of such improvement in Shaw and Yoshimura, would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, i.e., applying this known improvement technique in the same manner to the fuel combustor for a nitrogen-containing fuel of Selim, and the results would have been predictable and readily recognized, that integrating (Claim 4) a catalytically enhanced chemical reactor, (Claim 5) wherein said catalytically enhanced chemical reactor comprises a honeycomb catalyst support with catalyst carried by said support, and (Claim 6) wherein said catalyst is selected from one or more of metal oxide-based would have facilitated increasing the reduction of the NOx concentration of the combustion gas flowing from the fuel rich primary combustion zone. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1396; MPEP 2143(C).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Selim (2023/0313995A1) in view of Bulat (11,371,710).
Re Claim 7, Selim teaches the invention as claimed and as discussed above. Selim teaches a fuel combustor for a nitrogen-containing fuel, i.e., base device, upon which the claimed invention can be seen as an improvement. Selim is silent on wherein said relaxation zone comprises at least one internal gas flow recirculation path.
Bulat teaches, in Figs. 1 – 7, a similar fuel combustor (100) comprising: a rich fuel primary combustion zone; a NOx relaxation zone (Col. 7, l. 60 to Col. 8, l. 5) downstream from said fuel rich primary combustion zone; a combustion reaction quench zone downstream from said relaxation zone; and a secondary lean fuel combustion zone downstream from said combustion reaction quench zone, wherein said relaxation zone comprises at least one internal gas flow recirculation path (66 – Figs. 2 and 3).
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Thus, improving a particular device (fuel combustor for a nitrogen-containing fuel), based upon the teachings of such improvement in Bulat, would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, i.e., applying this known improvement technique in the same manner to the fuel combustor for a nitrogen-containing fuel of Selim, and the results would have been predictable and readily recognized, that integrating at least one internal gas flow recirculation path in said relaxation zone would have facilitated reducing the NOx concentration of the combustion gas flowing from the fuel rich primary combustion zone. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1396; MPEP 2143(C).
Claims 12, 13, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Selim (2023/0313995A1) in view of Design Choice.
Re Claims 12, 13, and 20, Selim teaches the invention as claimed and as discussed above; except, (Claims 12 and 20) wherein the ammonia fuel and the combustion air are not mixed prior to entering the (Claim 12) rich fuel combustion stage, (Claim 20) rich fuel primary combustion stage (interpreted as the “rich fuel primary combustion zone (56, 62)”), and (Claim 13) wherein the ammonia fuel is mixed with the combustion air in the rich fuel combustion stage. As discussed in the Duplicate Claims section above, Claims 12 and 13 are using different words to cover the same thing.
At the time the invention was made, it would have been an obvious matter of design choice to a person of ordinary skill in the art to modify Selim to separately inject the ammonia fuel and the combustion air into the rich fuel combustion stage because Applicant has not disclosed that “(Claims 12 and 20) wherein the ammonia fuel and the combustion air are not mixed prior to entering the rich fuel combustion stage and (Claim 13) wherein the ammonia fuel is mixed with the combustion air in the rich fuel combustion stage” provides an advantage, is used for a particular purpose, or solves a stated problem. In fact, Specification Para. [0057] discloses, “According to this embodiments, the nitrogen-containing fuel and air may be non-premixed, well mixed, or partially pre-mixed before any combustion process.” Claims 11 and 19 recite “wherein the ammonia fuel and the combustion air are mixed prior to entering the rich fuel combustion stage”. Therefore, Claims 12, 13, and 20 are mutually exclusive of Claims 11 and 19. The lack of criticality in the Specification and the mutually exclusive claims is indicative of the fact that the claimed non-premixed or premixed configurations are indeed a “Design Choice”, as all options perform equally well as Selim’s, and none of the options exhibits an advantage over the others and over Selim. One of ordinary skill furthermore, would have expected Applicant’s invention to perform equally well with Selim’s teaching, in Para. [0009], of the ammonia fuel and the combustion air are mixed prior to entering the rich fuel combustion stage because Applicant’s Claims 11 and 19 recite that configuration.
Therefore, it would have been an obvious matter of design choice to modify Selim to obtain the invention as specified in claim Claims 12, 13, and 20.
Claims 14 - 16 are rejected under 35 U.S.C. 103 as being unpatentable over Selim (2023/0313995A1) in view of Ito et al. (11,053,845) in view of Karan et al, “High-pressure and temperature ammonia flame speeds”, 13th Asia-Pacific Conference on Combustion 2021, ADNEC, Abu Dhabi – UAE, December 4 – 9, 2021, hereinafter “Karan” in view of Liu et al, “Kinetics Modeling on NOx Emissions of Gas Turbine Combustors for Syngas Applications”, GPPS-NA-2018-0055, Proceedings of Montreal 2018 Global Power and Propulsion Forum, May 7 – 9, 2018, hereinafter “Liu”.
Re Claim 14, Selim teaches the invention as claimed and as discussed above; except, wherein the pressure of the rich fuel primary combustion stage is in the range of about 1 to about 40 bar.
Ito teaches, in Figs. 1 – 3, Abstract, and Col. 3, ll. 60 – 65, a similar gas turbine engine having a fuel combustor (2) for ammonia fuel (Abstract) wherein the pressure of the primary combustion stage is in the range of 12 atmospheres which was equivalent to 12.159 bar which was within the claimed range of about 1 to about 40 bar.
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Selim with the pressure of the primary combustion stage is in the range of 12.159 bar (12 atmospheres), taught by Ito, because all the claimed elements, i.e., a gas turbine engine having a fuel combustor for ammonia fuel comprising: a rich fuel primary combustion zone; a NOx relaxation zone downstream from said fuel rich primary combustion zone; a combustion reaction quench zone downstream from said relaxation zone; and a secondary lean fuel combustion zone downstream from said combustion reaction quench zone, and wherein the rich fuel primary combustion zone has a primary combustion stage pressure of 12.159 bar (12 atmospheres), were known in the art, and one skilled in the art could have substituted the primary combustion stage pressure of 12.159 bar (12 atmospheres), taught by Ito, for the non-disclosed primary combustion stage pressure of Selim, with no change in their respective functions, to yield predictable results, i.e., during operation the compressor of the gas turbine engine would have compressed atmospheric air up to a pressure of around 12.159 bar and supplied said compressed air to the fuel combustor where the 12.159 bar compressed air would have mixed with the ammonia fuel and burned in the primary combustion stage defined inside the rich fuel combustion stage to generate combustion products that would have expanded through the turbine section of the gas turbine engine to generate rotational mechanical power to drive the compressor and a load. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
Selim, i.v., Ito, as discussed above, is silent on the temperature of the rich fuel primary combustion stage is in the range of about 1900 to about 2200 K.
Karan teaches, on Pg. 1, second column, first paragraph, that the adiabatic flame temperature of ammonia was 1800 °C which was equivalent to 2073.15 K (Kelvin) which was within the claimed range of about 1900 to about 2200 K.
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Selim, i.v., Ito, with the temperature of the ammonia fuel burning in the rich fuel primary combustion stage is 2073.15 K, taught by Karan, because all the claimed elements, i.e., a gas turbine engine having a fuel combustor for ammonia fuel comprising: a rich fuel primary combustion zone; a NOx relaxation zone downstream from said fuel rich primary combustion zone; a combustion reaction quench zone downstream from said relaxation zone; and a secondary lean fuel combustion zone downstream from said combustion reaction quench zone, and wherein the ammonia fuel burning in the rich fuel primary combustion stage had a flame temperature of 2073.15 K, were known in the art, and one skilled in the art could have substituted the temperature of the rich fuel primary combustion stage is 2073.15 K (Kelvin) which was within the claimed range of about 1900 to about 2200 K, taught by Karan, for the non-disclosed temperature of the rich fuel primary combustion stage of Selim, i.v., Ito, with no change in their respective functions, to yield predictable results, i.e., during operation the compressor of the gas turbine engine compressed air would have mixed with the ammonia fuel and burned in the primary combustion stage defined inside the rich fuel combustion stage around an adiabatic flame temperature of 2073.15 K resulting in the generation of combustion products that would have expanded through the turbine section of the gas turbine engine to generate rotational mechanical power to drive the compressor and a load. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
Selim, i.v., Ito and Karan, as discussed above, is silent on the residence time of the rich fuel primary combustion stage is in the range of about 1 to about 5 ms.
Liu teaches, on Pg. 3, first column, last paragraph, a similar gas turbine engine having a rich-quench-lean (RQL) fuel combustor with a residence time of the rich fuel primary combustion stage is in the range of about 1 to about 5 ms. Liu teaches, on Pg. 3, first column, last paragraph, “The residence time of rich-burn zone is 5 ms and that of lean-burn zone is 15 ms.”
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Selim, i.v., Ito and Karan, with the residence time of the rich fuel primary combustion stage is in the range of about 1 to about 5 ms, taught by Liu, because all the claimed elements, i.e., a gas turbine engine having a fuel combustor for ammonia fuel comprising: a rich fuel primary combustion zone; a NOx relaxation zone downstream from said fuel rich primary combustion zone; a combustion reaction quench zone downstream from said relaxation zone; and a secondary lean fuel combustion zone downstream from said combustion reaction quench zone, and the residence time of the rich fuel primary combustion stage is 5 ms, were known in the art, and one skilled in the art could have substituted the residence time of the rich fuel primary combustion stage is 5 ms which was within the claimed range of about 1 to about 5 ms, taught by Liu, for the non-disclosed residence time in the rich fuel primary combustion stage of Selim, i.v., Ito and Karan, with no change in their respective functions, to yield predictable results, i.e., during operation of the gas turbine engine ammonia fuel and compressed air would have been injected into the inlet end of the rich fuel combustion stage where a mixture of said ammonia fuel and compressed air would have burned in the primary combustion stage defined inside the rich fuel combustion stage resulting in the generation of combustion products that would have flowed through the outlet end of the rich fuel combustion stage where it took about 5 ms to flow from the inlet end to the outlet end of the rich fuel combustion stage. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
Re Claim 15, Selim, i.v., Ito, Karan, and Liu, teaches the invention as claimed and as discussed above; except, wherein the residence time of the relaxation stage is about 20 to about 1000 ms. Selim further teaches, in Para. [0036], “The longer second length 64 advantageously allows for increased NOx reduction and ammonia breakdown, which results in cleaner more efficient operation of the overall gas turbine 10.” Selim further teaches, in Para. [0066], “In some implementations, the method 500 may further include conveying combustion gases 34 through the second zone 58 in a residence time of between about 6 milliseconds and about 12 milliseconds, … In this way, the combustion gases 34, the unburned ammonia, and the NOx produced from the first zone 56 may travel together through the second zone 58 over a long period of time with insufficient oxidants, which advantageously promotes the consumption of NOx, thereby reducing the emissions”.
Therefore, the residence time of the relaxation stage was recognized as a result-effective variable, i.e. a variable which achieves a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B). In this case, the recognized result is that the greater the residence time, e.g., the greater the length of the relaxation stage, the increase in NOx reduction. Therefore, since the general conditions of the claim, i.e., that the relaxation stage/second zone had a residence time, were disclosed in the prior art by Selim, it is not inventive to discover the optimum workable range by routine experimentation, and it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the relaxation stage taught by Selim, i.v., Ito, Karan, and Liu, to have a residence time of about 20 to about 1000 ms. Furthermore, the range of about 20 to about 1000 ms for the residence time of the relaxation stage is recognized by the Examiner to be a very broad range, and a range that a person of ordinarily skill in the art would have found obvious at the time of the invention.
It has been held that “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); MPEP 2144.05(II)(A). It has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980); MPEP 2144.05(II)(B). In Smith v. Nichols, 88 U.S. 112, 118-19 (1874) the Supreme Court held that “a change in form, proportions, or degree "will not sustain a patent". It was held that "It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.", In re Williams, 36 F.2d 436, 438 (CCPA 1929); MPEP 2144.05(II)(A). Increasing the residence time of the relaxation stage merely involves only a change of proportions, e.g., longer relaxation stage, and as such is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.
Re Claim 16, Selim, i.v., Ito, Karan, and Liu, teaches the invention as claimed and as discussed above, including wherein the pressure of the lean fuel secondary combustion stage is in the range of about 1 to about 40 bar, see the Claim 14 rejection above. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that in a gas turbine engine fuel combustor the pressure of the lean fuel secondary combustion stage (containing the outlet end of the combustor) was only slightly less than the pressure of the rich fuel primary combustion stage (containing the inlet end of the combustor) because the pressure drop from the inlet end of the combustor to the outlet end of the combustor was very small (around about 0.3 bar) so that a pressure of 12.159 bar (12 atmospheres) in the rich fuel primary combustion stage would have resulted in a pressure of 11.859 bar (11.7 atmospheres) in the lean fuel secondary combustion stage.
Selim, i.v., Ito, Karan, and Liu, as discussed above, is silent on the temperature of the lean fuel secondary combustion stage is in the range of about 1600 to about 2050 K, and the residence time of the lean fuel secondary combustion stage is in the range of about 1 to about 20 ms.
Liu further teaches, on Pg. 3, first column, first paragraph, that “…the RQL combustor significantly reduces NOx emission when combustor outlet temperature is higher than 1670K”. The combustor outlet temperature is equivalent to the lean fuel secondary combustion stage and 1670K was within the claimed range of about 1600 to about 2050 K. As discussed in the Claim 14 rejection above, Liu teaches, on Pg. 3, first column, last paragraph, “The residence time of rich-burn zone is 5 ms and that of lean-burn zone is 15 ms.” The lean-burn zone is equivalent to the lean fuel secondary combustion stage.
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Selim, i.v., Ito, Karan, and Liu, with the temperature of the lean fuel secondary combustion stage is in the range of about 1600 to about 2050 K, and the residence time of the lean fuel secondary combustion stage is in the range of about 1 to about 20 ms, further taught by Liu, because all the claimed elements, i.e., a gas turbine engine having a fuel combustor for ammonia fuel comprising: a rich fuel primary combustion zone; a NOx relaxation zone downstream from said fuel rich primary combustion zone; a combustion reaction quench zone downstream from said relaxation zone; and a secondary lean fuel combustion zone downstream from said combustion reaction quench zone, and the temperature of the lean fuel secondary combustion stage is about 1670 K, and the residence time of the lean fuel secondary combustion stage is about 15 ms, were known in the art, and one skilled in the art could have substituted the temperature of the lean fuel secondary combustion stage is about 1670 K, and the residence time of the lean fuel secondary combustion stage is about 15 ms, further taught by Liu, for the non-disclosed temperature and residence time in the lean fuel secondary combustion stage of Selim, i.v., Ito, Karan, and Liu, with no change in their respective functions, to yield predictable results, i.e., during operation of the gas turbine engine ammonia fuel and compressed air would have been injected into the inlet end of the rich fuel combustion stage where a mixture of said ammonia fuel and compressed air would have burned in the primary combustion stage defined inside the rich fuel combustion stage resulting in the generation of combustion products that would have flowed through the lean fuel secondary combustion stage at about a temperature of 1670 K to reduce NOx emission and at a residence time of about 15 ms to facilitate complete combustion of any unburned fuel with the fresh oxygen supplied by the quench air thereby increasing fuel efficiency and reducing the emission of unburned fuel in the exhaust gases of the gas turbine. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
Conclusion
THIS ACTION IS MADE FINAL. 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.
Response to Arguments
Applicant's arguments filed 01/12/2026 have been fully considered but they are not persuasive.
Applicant argues on Pgs. 8 – 9 regarding the Duplicate Claim, Warning of Claims 12 and 13 that “Claim 13 uses the transition "comprising" and therefore does not preclude mixing ammonia fuel with combustion air prior to entering the rich fuel combustion stage of the combustor and then further mixing the fuel and air after entering the rich fuel combustion stage”. This argument is not persuasive because it is wrong. Neither original Claim 13 nor original Claim 12 recite the transition phrase “comprising”. The full text of was “13. (Original) The method of claim 10, wherein the ammonia fuel is mixed with the combustion air in the rich fuel combustion stage.”. The Duplicate Claim, Warning is maintained.
Applicant argues on Pg. 9 under heading 35 USC § 102 regarding Claim 1 that “Present claim 1 includes an additional relaxation zone downstream of the rich fuel combustion zone. The relaxation zone needs to approach equilibrium of the NOx chemistry. The NOx chemistry (and its equilibrium) requires an extension of the hot gas residence time and a distinct zone (i.e., the relaxation zone) to provide this extended residence time. NOx equilibrium is not disclosed in Selim.” In response to applicant's argument that reference Selim failed to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., “The relaxation zone needs to approach equilibrium of the NOx chemistry.” and “NOx equilibrium is not disclosed in Selim”.) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). It has been held that “During examination, the claims must be interpreted as broadly as their terms reasonably allow”. In re American Academy of Science Tech Center, 367 F.3d 1359, 1369, 70 USPQ2d 1827, 1834 (Fed. Cir. 2004); MPEP 2111.01. Claim 1 only recited “…a NOx relaxation zone downstream from said fuel rich primary combustion zone; a combustion reaction quench zone downstream from said relaxation zone;”. Selim disclosed, in Para. [0040], “In the second zone 58, a controlled depletion of NOx may be achieved by introducing a second portion of oxidant or air 104 (e.g., approximately 5%-15% of the total oxidant) may be introduced over a long distance and time period (e.g., between about 6 ms and about 12 ms)”. Therefore, Selim’s second zone (58, 64) reads on the claimed “relaxation zone”. Furthermore, it has been held that “[A]pparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original); MPEP 2114. It has also been held that, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established”. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977); MPEP 2112.01. A claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987); MPEP 2114(II). A recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. The structure of the applied prior art, being similar to the structure of the present application, as claimed and disclosed, the two structures will obviously function the same under similar circumstances. As discussed in the Claim 1 rejection above, Selim teaches all of the structural limitations of the claim. The rejections are maintained.
Applicant’s arguments on Pg. 9 – 10 under heading 35 USC § 103 regarding Claims 4 – 6, 7, 12 - 16, and 20 all refer back to Applicant’s prior argument about Claim 1 which is discussed above. The rejections are maintained.
Applicant further argues on Pgs. 10 - 11 under heading 35 USC § 103 that “Selim's second combustion zone 58 operates on a vastly different principal as compared to Applicant's relaxation zone.” and therefore “Selim does not disclose a relaxation zone as described in the present application”. Again this argument is not persuasive because Applicant appears to be reading limitations from the specification into the claims which is not allowed, See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). It has been held that “During examination, the claims must be interpreted as broadly as their terms reasonably allow”. In re American Academy of Science Tech Center, 367 F.3d 1359, 1369, 70 USPQ2d 1827, 1834 (Fed. Cir. 2004); MPEP 2111.01. As discussed in the Claim 1 rejection above, Selim teaches all of the structural limitations of the claim. It has been held that “[A]pparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original); MPEP 2114. It has also been held that, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established”. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977); MPEP 2112.01. A claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987); MPEP 2114(II). A recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. The structure of the applied prior art, being similar to the structure of the present application, as claimed and disclosed, the two structures will obviously function the same under similar circumstances. The rejections are maintained.
Correspondence
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/LORNE E MEADE/Primary Examiner, Art Unit 3741
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