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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 01/07/2026 has been entered.
Claims 1 and 3-5 are currently being examined.
Claim Rejections - 35 USC § 103
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.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1 and 3-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Codron et al. 20100304316 in view of NPL Engineering Toolbox 2005: Heating Values of Fuel Gases, Iijima 6298651, Yamashita 20170051237 and NPL IEA 2020: Outlook for Biogas and Biomethane, Sood et al. 4833878 and Menon et al. 20140283523.
Regarding independent claim 1, Codron teaches a fuel supply system (Fig. 1) comprising:
a fuel gas supply line (fuel line of NG, natural gas, fuel in Fig. 1 and as described in para. 0020 as one of fuel sources 12; per para. 0022, piping 14 that connects the multiple fuel sources 12 to the combustion engine 16 may be any manner of conduit, line, or transmission means for conveying fuel from a fuel source to a destination) configured to supply a fuel gas (natural gas NG is supplied through valve 18 and valve 24 which are controlled by controller 40 shown in Figs. 1-2, paras. 0028-0033) to a combustor of a gas turbine (16 Fig. 1; para. 0002 describes a gas turbine engine with combustors as an example of a combustion engine 16; the fuel control system 10 generally includes multiple fuel sources 12, piping 14 that connects the multiple fuel sources 12 to combustion engine 16, and instrumentation and control equipment to combine the multiple fuel sources 12 in the necessary proportions to produce a fuel having a desired calorie content);
a first off-gas supply device (valve 18 next to COG flow arrow in Fig. 1) configured to supply a first off-gas (coke oven gas COG; para. 0020 describes a fuel supply of COG is supplied via respective valve 18 to combustor of gas turbine 16) to the combustor;
a second off-gas supply device (valve 18 next to BFG flow arrow in Fig. 1); per para. 0020, respective valve 18 connects fuel source, i.e., supply, of BFG, blast furnace gas, to piping 14) configured to supply a second off-gas (blast furnace gas BFG; para. 0020 describes a fuel supply of BFG is supplied via respective valve 18 to combustor of gas turbine 16; blast furnace gas has a low calorie content per para. 0021) to the combustor, the second off-gas having a calorific value per unit mass smaller than the fuel gas (per NPL Engineering Toolbox, calorific value per unit mass of blast furnace gas is 2740 kJ/kg and calorific value per unit mass of natural gas is 40705 kJ/kg such that calorific value for blast furnace gas is smaller than the calorific value of natural gas);
a gas mixing device (26 Fig. 1 which per para. 0023 is a mixing point) configured to mix the fuel gas supplied by the fuel gas supply line, the first off-gas supplied by the first off-gas supply device, and the second off-gas supplied by the second off-gas supply device (per para. 0023, mixing point 26 may include any structure for combining the low and high energy fuels, such as a tank or simply the piping where the low and high energy supply lines meet, i.e., is configured to mix each of the fuel gas, first off-gas and second off-gas); and
a mixed gas fuel supply line (fuel line from 26 to 16 in Fig. 1) configured to supply a mixed gas fuel produced by the gas mixing device to the combustor (per para. 0026, from gas mixing device 26 a mixed gas fuel typically passes through one or more system processes to produce processed mixed fuel before reaching gas turbine 16; per para. 0031 controller 40 determines the desired calorie content 54 based on a third control signal 46, which is reflective of the operating level of the gas turbine 16),
wherein the fuel gas supply line includes
a mixing fuel gas supply line (assembly of line from NG fuel source flow arrow to valve 18 to supply line 22 to control valve 24 to gas mixing device 26 in Fig. 1) connected to the gas mixing device (mixing fuel gas supply line connects to mixing device 26 via supply line 22 extending to control valve 24 and then to 26 in Fig. 1), and configured to supply the fuel gas (natural gas NG) to the gas mixing device (26).
Codron in view of NPL Engineering Toolbox does not explicitly teach the first off-gas generated in a fuel refining plant, the second off-gas generated in a bio-liquid fuel production plant, the fuel gas supply line includes a start-up fuel gas supply line that is connected to the combustor and configured to supply the fuel gas as a start-up fuel to the combustor while bypassing the gas mixing device during a period in which the mixed gas fuel is not supplied from the mixed gas fuel supply line to the combustor, and the mixing fuel gas supply line provided in parallel with the start-up fuel gas supply line.
Iijima teaches coke oven gas and coke are generated in a coke oven when heating coal during a carbonization process to produce the coke oven gas and coke in a carbonization apparatus (col 18 lines 65-67 to col 19 lines 1-12), i.e., a fuel refining plant, as the coke oven gas may be used as a fuel in a gas turbine (col 7 lines 63-67 to col 8 lines 1-6) and coke may be used as a fuel in a boiler (col 7 lines 49-53).
"The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results. . . . [W]hen a patent 'simply arranges old elements with each performing the same function it had been known to perform' and yields no more than one would expect from such an arrangement, the combination is obvious." KSR at 1395-66 (citing Sakraida v. AG Pro, Inc., 425 U.S. 273, 282 (1976)).
One of ordinary skill in the art could have applied the known means of producing coke oven gas in a fuel refining plant as taught by Iijima to predictably produce an off-gas useable as a fuel.
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have the first off-gas in the invention of Codron in view of NPL Engineering Toolbox generated in a fuel refining plant as taught by Iijima because the known technique of producing coke oven gas in a fuel refining plant was part of the ordinary capabilities of a person of ordinary skill in the art.
Codron in view of NPL Engineering Toolbox and Iijima is silent on the second off-gas generated in a bio-liquid fuel production plant, the fuel gas supply line includes a start-up fuel gas supply line that is connected to the combustor and configured to supply the fuel gas as a start-up fuel to the combustor while bypassing the gas mixing device during a period in which the mixed gas fuel is not supplied from the mixed gas fuel supply line to the combustor, and the mixing fuel gas supply line provided in parallel with the start-up fuel gas supply line.
Yamashita teaches a biogas (X6a and X6 per para. 0027) is an off-gas generated in a bio-liquid fuel production plant (Fig. 1; liquid fuelization facility 7 produces a bio-liquid fuel X8 per para. 0028). According to NPL IEA 2020: Outlook for Biogas and Biomethane page 2 para. 5, the lower heating value, i.e., the calorific value, of biogas is 16-28 MJ/m3, and on page 18 para. 3, biogas as a biofuel is a renewable energy source. According to NPL Engineering Toolbox, the calorific value of natural gas in kJ/ m3 is 31670 kJ/ m3 which is 31.670 MJ/ m3, such that the calorific value of biogas is smaller than the calorific value of natural gas. NPL Engineering Toolbox shows the calorific value of natural gas both in terms of calorific value per unit mass (kg) and per m3 such that since the calorific value of biogas in terms of calorific value per m3 is smaller than the calorific value per m3 of natural gas, the calorific value per unit mass of biogas is then correspondingly smaller than the calorific value per unit mass of natural gas which reads on the second off-gas having a calorific value per unit mass smaller than the fuel gas as claimed.
"[I]f a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious unless its actual application is beyond his or her skill. . . . [A] court must ask whether the improvement is more than the predictable use of prior art elements according to their established functions." KSR at 1396.
One of ordinary skill in the art could have applied the known means of producing a biogas in a bio-liquid fuel production plant as taught by Yamashita to predictably produce another off-gas which is useable as a fuel from a renewable fuel source and is of a smaller calorific value than natural gas, with calorific values as taught by NPL Engineering Toolbox and NPL IEA.
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have the second off-gas in the invention of Codron in view of NPL Engineering Toolbox and Iijima be biogas generated in a bio-liquid fuel production plant as taught by Yamashita and NPL IEA because the technique of producing biogas in a bio-liquid fuel production plant was part of the ordinary capabilities of a person of ordinary skill in the art, in view of the teaching of Yamashita as well as biogas is a renewable fuel source in view of NPL IEA.
Codron in view of NPL Engineering Toolbox, Iijima, Yamashita and NPL IEA is silent regarding the fuel gas supply line includes a start-up fuel gas supply line that is connected to the combustor and configured to supply the fuel gas as a start-up fuel to the combustor while bypassing the gas mixing device during a period in which the mixed gas fuel is not supplied from the mixed gas fuel supply line to the combustor, and the mixing fuel gas supply line provided in parallel with the start-up fuel gas supply line.
Sood teaches, similarly to Codron, that natural gas may be used as a fuel for a gas turbine engine and that natural gas is a relatively high calorific value fuel (col 1 lines 14-27). Sood further teaches that it is very difficult to start a gas turbine engine on low calorific value fuel (col 1 lines 29-32).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have the fuel gas supply line of the invention of Codron in view of NPL Engineering Toolbox, Iijima, Yamashita and NPL IEA configured to supply the fuel gas which is natural gas as a start-up fuel to the combustor as taught by Sood since natural gas has a higher calorific value which facilitates starting the gas turbine.
Codron in view of NPL Engineering Toolbox, Iijima, Yamashita and NPL IEA and Sood does not explicitly teach the fuel gas supply line includes a start-up fuel gas supply line that is connected to the combustor and configured to supply the fuel gas as a start-up fuel to the combustor while bypassing the gas mixing device during a period in which the mixed gas fuel is not supplied from the mixed gas fuel supply line to the combustor, and the mixing fuel gas supply line provided in parallel with the start-up fuel gas supply line.
Menon teaches a fuel system (Fig. 3) for a combustor (14 Fig. 1) of a gas turbine (Fig. 1) with a natural gas supply 78 with gas release valve 100 and a process gas supply 76, i.e., off-gas supply, with gas release valve 102 and a controller 80 which controls valves 100 and 102 as well as control valves 104, 106, 108 and 110 as shown in Fig. 3 (para. 0031), in which fuel nozzles route gaseous fuel and/or blended fuel from the fuel blending system 50 to primary and secondary combustion zones to combustor 14 and the fuel may be natural gas, a process gas and/or a mixture of natural gas and process gas (Fig. 2 para. 0019).
Menon teaches a fuel gas supply line (90, 92 Fig. 3) includes a start-up fuel gas supply line (90 which is a natural gas fuel gas supply line extending from natural gas supply 78 to primary fuel nozzle 20 in Fig. 3) that is connected to a combustor (90 is connected to combustor 14 via primary fuel nozzle 20 as shown in Figs. 1-3) and configured to supply the fuel gas as a start-up fuel to the combustor (natural gas may be supplied to primary fuel nozzle 20 via the natural gas fuel gas supply line 90 when valve 100 is directed to release the natural gas and control valve 104 regulates the flow of natural gas in 90 to the primary fuel nozzle with control valve 106 not allowing flow of process gas to 90 as when controller 80 employs a startup mode per para. 0036) while bypassing a gas mixing device (90 bypasses a gas mixing device labeled mixing point in annotated Fig. 3) during a period in which a mixed gas fuel (mix of process gas from 76 and natural gas from 78) is not supplied from a mixed gas fuel supply line (line 92 from mixing point to secondary fuel nozzle 22 in annotated Fig. 3) to the combustor (when controller 80 employs a startup mode and valves 102, 110 are closed, a mixed gas fuel is not supplied from line 92 to the combustor via secondary fuel nozzle 22), and the mixing fuel gas supply line provided in parallel with the start-up fuel gas supply line (as shown in annotated Fig. 3, mixing fuel gas supply line 92 is provided in parallel with start-up fuel gas supply line 90).
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It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the invention of Codron in view of NPL Engineering Toolbox, Iijima, Yamashita and NPL IEA and Sood to have the fuel gas supply line includes a start-up fuel gas supply line that is connected to the combustor and configured to supply the fuel gas as a start-up fuel to the combustor while bypassing the gas mixing device during a period in which the mixed gas fuel is not supplied from the mixed gas fuel supply line to the combustor, and the mixing fuel gas supply line provided in parallel with the start-up fuel gas supply line as taught by Menon to allow the fuel gas which is natural gas or a blend of the natural gas with off-gas to be supplied to primary and secondary combustion zones of the combustor depending on the operation mode of the gas turbine.
Regarding claim 3, Codron in view of NPL Engineering Toolbox, Iijima, Yamashita and NPL IEA, Sood and Menon teaches all that is claimed in claim 1, and Codron further teaches
a first off-gas supply line (fuel line connected to valve 18 adjacent COG fuel supply arrow in Fig. 1) configured to supply the first off-gas from the first off-gas supply device to the gas mixing device (first off-gas COG is sent via its respective valve 18 to line 22 to control valve 24 to gas mixing device 26 in Fig. 1), and
a second off-gas supply line (fuel line 20 in Fig. 1) configured to supply the second off-gas from the second off-gas supply device to the gas mixing device (as modified in view of Yamashita, biogas as the second off-gas replaces BFG and is supplied to valve 18 connected to fuel line 20 to gas mixing device 26 in Fig. 1),
wherein the mixing fuel gas supply line is configured to start supplying the fuel gas to the gas mixing device before the first off-gas supply line starts supplying the first off-gas and before the second off-gas supply line starts supplying the second off-gas (per para. 0002, at low power levels the fuel injection system must provide fuel with a relatively high calorie content to maintain combustion and avoid “blow out” of the flame such that at a low power level or mode as determined by controller 40 which also controls control valve 24, fuel gas which is high calorie natural gas can be supplied to mixing device 26 before the first off-gas or second off-gas is supplied via respective valves 18 to maintain a higher calorie fuel sent to the combustor to avoid blow out).
Regarding claim 4, Codron in view of NPL Engineering Toolbox, Iijima, Yamashita and NPL IEA, Sood and Menon teaches all that is claimed in claim 3, and further teaches the following limitations which have functional language in which the term “before” is relative to timing but since no specific frame of reference for timing is provided in the claim the relative timing can be related to any given time, day, week, etc., when the system may be in use:
the first off-gas supply line is configured to start supplying the first off-gas before the second off-gas supply line starts supplying the second off-gas (controller 40 of Codron controls operation of valve 24 and other valves based on a desired calorie content of fuel sent to the combustor of gas turbine 16 per para. 0031 based on sensor information per paras. 0027-0029 as well as on availability of a fuel per para. 0021, such that at an operation mode requiring a desired calorie content of the fuel when the second off-gas is not available, the first off-gas may be supplied via its respective valve 18 and valve 24 as required to result in the desired calorie content of the fuel before a time when the second off-gas fuel may become available), and
the mixed gas fuel supply line is configured to supply a first mixed gas fuel to the combustor before the second off-gas supply line starts supplying the second off-gas (controller 40 of Codron controls operation of valve 24 and other valves based on a desired calorie content of fuel sent to the combustor of gas turbine 16 per para. 0031 based on sensor information per paras. 0027-0029 as well as on availability of a fuel per para. 0021, such that at an operation mode requiring a desired calorie content of mixed fuel when the second off-gas is not available, available fuels NG and COG may be supplied via respective valves 18 and valve 24 per controller 40 to gas mixing device 26 which provides a first mixed gas fuel containing NG and COG to the combustor before a time when the second off-gas fuel may become available),
the first mixed gas fuel being produced by the gas mixing device and containing the fuel gas and the first off-gas (as discussed above, the first mixed gas fuel produced by gas mixing device 26 contains fuel gas NG and first off-gas COG based on fuel availability and a desired calorie content of the mixed gas fuel).
Regarding claim 5, Codron in view of NPL Engineering Toolbox, Iijima, Yamashita and NPL IEA, Sood and Menon teaches all that is claimed in claim 3, and further teaches the following limitations which have functional language in which the term “before” is relative to timing but since no specific frame of reference for timing is provided in the claim the relative timing can be related to any given time, day, week, etc., when the system may be in use:
the second off-gas supply line is configured to start supplying the second off-gas before the first off-gas supply line starts supplying the first off-gas (controller 40 of Codron controls operation of valve 24 and other valves based on a desired calorie content of fuel sent to the combustor of gas turbine 16 per para. 0031 based on sensor information per paras. 0027-0029 as well as on availability of a fuel per para. 0021, such that at an operation mode requiring a desired calorie content of the fuel when the first off-gas is not available, the second off-gas may be supplied via its respective valve 18 and line 20 as required to result in the desired calorie content of the fuel before a time when the first off-gas fuel may become available), and
the mixed gas fuel supply line is configured to supply a second mixed gas fuel to the combustor before the first off-gas supply line starts supplying the first off-gas (controller 40 of Codron controls operation of valve 24 and other valves based on a desired calorie content of fuel sent to the combustor of gas turbine 16 per para. 0031 based on sensor information per paras. 0027-0029 as well as on availability of a fuel per para. 0021, such that at an operation mode requiring a desired calorie content of the mixed fuel when the first off-gas is not available, available fuels NG via respective valve 18 and valve 24 and biogas via respective valve 18 and line 20 may be supplied via per controller 40 to gas mixing device 26 which provides a second mixed gas fuel containing fuel gas NG and second off-gas biogas to the combustor before a time when the first off-gas fuel may become available),
the second mixed gas fuel being produced by the gas mixing device and containing the fuel gas and the second off-gas (as discussed above, the second mixed gas fuel produced by gas mixing device 26 contains fuel gas NG and second off-gas biogas based on fuel availability and a desired calorie content of the mixed gas fuel).
Response to Arguments
Applicant's arguments filed 01/07/2026 have been fully considered but they are not persuasive. Applicant argues regarding the 103 rejection of claim 1 on page 8 of Remarks that Menon teaches the destination of bypass line 90 is primary fuel nozzle 20 and destination of mixed gas line 92 is the secondary fuel nozzle 22 to supply different zones within the combustor, while in the instant invention the destination of both start-up line 72 and mixed gas line 4 is the combustor 3 with the purpose of switching the supply path between start-up and normal operation. However, in Menon the primary fuel nozzle 20 and the secondary fuel nozzle 22 supply the fuel from respectively lines 90 and 92 to combustor 14 as shown in Figs. 1-2, and Menon does teach providing different fuel circuits via lines 90 and 92 to the combustor based on operational modes such as discussed in paras. 0032 to 0036.
Applicant argues on page 9 of Remarks that Menon does not disclose or suggest “a start-up fuel gas supply line configured to supply the fuel gas as a start-up fuel to the combustor while bypassing the gas mixing device during a period in which the mixed gas fuel is not supplied from the mixed gas fuel supply line to the combustor.”
However, Menon does teach this limitation as shown below and as described above in the current 103 rejection of claim 1:
Menon teaches a fuel gas supply line (90, 92 Fig. 3) includes a start-up fuel gas supply line (90 which is a natural gas fuel gas supply line extending from natural gas supply 78 to primary fuel nozzle 20 in Fig. 3) that is connected to a combustor (90 is connected to combustor 14 via primary fuel nozzle 20 as shown in Figs. 1-3) and configured to supply the fuel gas as a start-up fuel to the combustor (natural gas may be supplied to primary fuel nozzle 20 via the natural gas fuel gas supply line 90 when valve 100 is directed to release the natural gas and control valve 104 regulates the flow of natural gas in 90 to the primary fuel nozzle with control valve 106 not allowing flow of process gas to 90 as when controller 80 employs a startup mode per para. 0036) while bypassing a gas mixing device (90 bypasses a gas mixing device labeled mixing point in annotated Fig. 3) during a period in which a mixed gas fuel (mix of process gas from 76 and natural gas from 78) is not supplied from a mixed gas fuel supply line (line 92 from mixing point to secondary fuel nozzle 22 in annotated Fig. 3) to the combustor (when controller 80 employs a startup mode and valves 102, 110 are closed, a mixed gas fuel is not supplied from line 92 to the combustor via secondary fuel nozzle 22), and the mixing fuel gas supply line provided in parallel with the start-up fuel gas supply line (as shown in annotated Fig. 3, mixing fuel gas supply line 92 is provided in parallel with start-up fuel gas supply line 90).
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It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the invention of Codron in view of NPL Engineering Toolbox, Iijima, Yamashita and NPL IEA and Sood to have the fuel gas supply line includes a start-up fuel gas supply line that is connected to the combustor and configured to supply the fuel gas as a start-up fuel to the combustor while bypassing the gas mixing device during a period in which the mixed gas fuel is not supplied from the mixed gas fuel supply line to the combustor, and the mixing fuel gas supply line provided in parallel with the start-up fuel gas supply line as taught by Menon to allow the fuel gas which is natural gas or a blend of the natural gas with off-gas to be supplied to primary and secondary combustion zones of the combustor depending on the operation mode of the gas turbine.
Therefore, the rejection of claim 1 using supplemental reference Menon is proper.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALYSON JOAN HARRINGTON whose telephone number is (571)272-2359. The examiner can normally be reached M-F 9 am - 5 pm EST.
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/A.J.H./
Examiner, Art Unit 3741
/LORNE E MEADE/Primary Examiner, Art Unit 3741