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 .
Response to Arguments
Applicant’s arguments, see Page 7, lines 8-18 of Remarks, filed July 15th, 2026, with respect to claims 20-21 been fully considered and are persuasive. The rejection of claims 20-21 under 35 U.S.C. 112(b)/2nd Paragraph of April 16th, 2026 has been withdrawn.
Applicant’s arguments, see Page 7, line 8 – Page 13, line 8 of Remarks, filed July 15th, 2026, with respect to the rejections of claims 1-4, 6-7, and 9-22 under 35 U.S.C. 103 have been fully considered and are persuasive. Due to amendments to claims 1 and 22, the rejections have been withdrawn. However, upon further consideration, new grounds of rejection are made in view of the prior art over the amended claims.
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.
Claims 1, 4, 6-7, 10-11, 13-14, 16, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Lee (U.S. 2015/0233290 A1) in view of Allam (U.S. 2023/0150817 A, effectively filed November 18th, 2021 by virtue of U.S. Provisional Application 63/280,774).
Regarding claim 1, Lee teaches a process for producing hydrogen (Lee, Fig. 1, [0014]-[0042]), comprising:
introducing heat and a source gas comprising natural gas into a steam methane reformer to produce a reformer product stream comprising hydrogen and carbon monoxide (Lee, Fig. 1, [0039], “A stream of natural gas and steam are supplied via lines 1 and 2, respectively to steam reforming reaction zone 3. Heat needed for the endothermic reaction is provided by a hot gas stream that is supplied to the reaction zone via line 4.”);
subjecting the reformer product stream to a water-gas shift reaction to produce a water-gas shift product stream; the water-gas shift reaction comprising reacting the carbon monoxide with water to produce carbon dioxide and hydrogen (Lee, Fig. 1, [0041], “Cooled synthesis gas obtained in heat recovery steam generator 14 is supplied via line 20 to water-gas shift reaction zone 21 wherein it is converted (with steam supplied via line 22) into water-gas shifted gaseous mixture comprising hydrogen and carbon dioxide.”);
removing carbon dioxide from the water-gas shift product stream to produce a CO2-depleted hydrogen stream (Lee, Fig. 1, [0041], “This mixture is supplied via line 23 to carbon dioxide removal zone 24 to remove at least part of the carbon dioxide (discharged via line 25) and to obtain a gaseous stream enriched in hydrogen.”; and
subjecting the CO2-depleted hydrogen stream to a pressure-swing adsorption process to adsorb at least a portion of the undesirable components and produce a hydrogen product stream (Lee, Fig. 1, [0041], “Optionally, the gaseous stream enriched in hydrogen is further purified in hydrogen by subjecting this stream to pressure swing absorption (not shown) prior to supply to hydrogen liquefaction unit 27.”);
wherein a portion of the hydrogen product stream is recovered as a hydrogen product (Lee, Fig. 1, [0041], “This stream is supplied via line 26 to a hydrogen liquefaction unit 27 and
liquefied to obtain liquid hydrogen 28.”); and
wherein a hydrogen-fueled gas turbine produces at least a portion of the heat introduced into the steam methane reformer (Lee, Fig. 1, [0039], “Heat needed for the endothermic reaction is provided by a hot gas stream that is supplied to the reaction zone via line 4. The hot gas stream is generated in gas turbine 5 comprising in series compressor 6, combustion chamber 7 and expansion turbine 8 that is directly connected to electric generator 9.”; [0023], “The fuel fed to the turbine may be any gaseous fuel known to be suitable as turbine feed. Preferably, the turbine is a gas turbine and the fuel is a gaseous fuel. Preferred fuels include hydrogen and hydrocarbon fuels such as natural gas, methane, ethane, propane, liquefied propane gas (LPG), and biogas, hydrogen, or combinations of two or more thereof.”).
Lee does not explicitly teach that a first portion of the hydrogen product stream is directed to the hydrogen-fueled gas turbine as a source of fuel. However, as cited above, Lee teaches hydrogen as a preferred fuel for the turbine (Lee, [0023]). Additionally, Allam teaches producing hydrogen by reforming and using a portion of the hydrogen produced to fuel a turbine to provide heat for a steam methane reformer (Allam, [0114], [0128], “In some embodiments, the substantially pure hydrogen from the PSA can be mixed with nitrogen preheated in the hydrogen plant and used as fuel gas for a gas turbine.”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have directed a first portion of Lee’s hydrogen product stream to the hydrogen-fueled gas turbine as a source of fuel. The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art (see MPEP 2143.A.). The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, USPQ2d 1385, 1395 - 97 (2007) (see MPEP § 2143.B.). In the instant case, it was already known that separating a portion of hydrogen produced from reforming and purified by pressure-swing absorption could readily be used to supply fuel for a gas turbine (Allam, [0128]). Since Lee uses a hydrogen-fueled turbine (Lee, [0023]), doing so would yield the predictable result of fueling Lee’s turbine.
Regarding claim 4, modified Lee renders the process of claim 1 obvious, as discussed above, wherein the undesirable components adsorbed from the CO2-depleted stream are methane (Lee, [0003], [0032]).
Regarding claims 6-7, modified Lee renders the process of claim 1 obvious, as discussed above. While Lee does not explicitly teach that the methanation process comprises contacting the CO2-depleted hydrogen stream with a methanation catalyst (claim 6) or that the methanation catalyst comprises nickel (claim 7), these limitations only pertain to the option in claim 1 of “subjecting the CO2-depleted hydrogen stream to a methanation process to produce a hydrogen product stream” selected from the alternatives “subjecting the CO2-depleted hydrogen stream to a pressure-swing adsorption process to adsorb at least a portion of the undesirable components and produce a hydrogen product stream or subjecting the CO2-depleted hydrogen stream to a methanation process to produce a hydrogen product stream” (emphasis added). As modified Lee reads on the former alternative, the additional limitations of claims 6-7, directed to the latter alternative, are not required to render the claims obvious.
Regarding claim 10, modified Lee renders the process of claim 1 obvious, as discussed above, wherein the steam methane reformer comprises a reactor having a catalyst disposed therein (Lee, [0016]).
Regarding claim 11, modified Lee renders the process of claim 10 obvious, as discussed above, wherein the catalyst is nickel (Lee, [0016], “Nickel-based catalysts, i.e. catalysts comprising nickel as catalytically active metal, are particularly preferred and are commercially available.”).
Regarding claim 13, modified Lee renders the process of claim 1 obvious, as discussed above, wherein the water-gas shift reaction comprises contacting the reformer product stream with a catalyst (Lee, [0030]).
Regarding claim 14, modified Lee renders the process of claim 13 obvious, as discussed above, wherein the water-gas shift reaction comprises cooling the reformer product stream prior to contact with the catalyst (Lee, [0030], “Since the gaseous mixture obtained in steam reforming step (a) typically has a temperature that is higher than the temperature in the first stage of the water-gas shift reaction, the gaseous mixture obtained in step (a) is typically cooled before being subjected to a water-gas shift reaction.”).
Regarding claim 16, modified Lee renders the process of claim 1 obvious, as discussed above, wherein CO2 is removed from the water-gas shift product stream by a process comprising membrane separation (Lee, [0031]).
Regarding claim 19, modified Lee renders the process of claim 1 obvious, as discussed above, further comprising generating steam from the latent heat of the reformer product stream (Lee, [0035]).
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Lee (U.S. 2015/0233290 A1) in view of Allam (U.S. 2023/0150817 A, effectively filed November 18th, 2021 by virtue of U.S. Provisional Application 63/280,774), as applied to claim 11 above, and further in view of Harrison (U.S. 2023/0147136 A1, filed April 23rd, 2022).
Regarding claim 12, modified Lee renders the process of claim 11 obvious, as discussed above, but does not explicitly teach that the catalyst comprises zinc and copper. However, Harrison teaches that copper-zinc is a suitable catalyst for steam reforming (Harrison, [0110]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have selected copper-zinc as the steam reforming catalyst in Lee’s process. The selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. See In re Leshin, 125 USPQ 416 (CCPA 1960), Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945), and MPEP § 2144.07. In the instant case, Harrison teaches that copper-zinc is a suitable catalyst for steam methane reforming (Harrison, [0110]).
Claims 2 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Lee (U.S. 2015/0233290 A1) in view of Allam (U.S. 2023/0150817 A, effectively filed November 18th, 2021 by virtue of U.S. Provisional Application 63/280,774), as applied respectively to claims 1 and 13 above, and further in view of Ravikumar (U.S. 2022/0267147 A1, filed 2-22-22; US Prov’l Appl’n filed 2-22-21).
Regarding claim 2, modified Lee renders the process of claim 1 obvious as detailed above, but does not explicitly teach that the pressure-swing adsorption (PSA) process comprises contacting the CO2-depleted stream with a zeolite adsorbent material. However, Ravikumar teaches that a zeolite adsorbent material is appropriate for use in a pressure-swing adsorption process (Ravikumar, [0082]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have included a zeolite adsorbent material in the PSA unit of Lee (Lee, [0041]) and thereby to have contacted the CO2-depleted stream with a zeolite adsorbent material. The selection of a known material based upon its suitability for an intended use is within the ambit of one of ordinary skill in the art. See In re Leshin, 125 USPQ 416 (CCPA 1960), Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327 (1945); MPEP § 2144.07. Here, a zeolite adsorbent material was known to be suitable for use as an adsorbent in a PSA unit (Ravikumar, [0082]).
Regarding claim 15, modified Lee renders the process of claim 13 obvious, as discussed above, but does not explicitly teach that the catalyst comprises a base metal. However, Ravikumar teaches that a base metal is an appropriate material to use as a catalyst in a water-gas shift reaction (Ravikumar, [0062], cobalt, molybdenum, copper, iron, cobalt-molybdenum, and chromium are all listed as suitable catalysts).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have selected a base metal as the catalyst in Lee’s water-gas shift reaction. The selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. See In re Leshin, 125 USPQ 416 (CCPA 1960), Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945), and MPEP § 2144.07. In the instant case, a base metal was known as a suitable material to use as a water-gas shift reaction catalyst (Ravikumar, [0062], cobalt, molybdenum, copper, iron, cobalt-molybdenum, and chromium are all listed as suitable catalysts).
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over Lee (U.S. 2015/0233290 A1) in view of Allam (U.S. 2023/0150817 A, effectively filed November 18th, 2021 by virtue of U.S. Provisional Application 63/280,774), as applied respectively to claims 1 and 13 above, and further in view of Wynn (U.S. 2012/0141367 A1).
Regarding claim 17, modified Lee renders the process of claim 1 obvious, as discussed above, but does not explicitly teach a concentration of CO2 in the CO2-depleted stream. However, Wynn teaches that membrane separation of carbon dioxide from a shifted syngas stream, similarly to Lee (Lee, [0031]) can produce a CO2-depleted stream having a concentration of CO2 of 23 wt% (Wynn, Table 2, [0077], Residue Stream (515), 25.5 mol% H2, 10.4 mol% CO2, 41.3 mol% CO, 22.7 mol% CH4).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have had the concentration of CO2 in Lee’s CO2-depleted stream be 23 wt%, as Lee is directed toward removing CO2 to produce this stream using membrane separation, and Wynn teaches that such a purity is possible to achieve using this process (Wynn, Table 2, [0077], Residue Stream (515)).
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Lee (U.S. 2015/0233290 A1) in view of Allam (U.S. 2023/0150817 A, effectively filed November 18th, 2021 by virtue of U.S. Provisional Application 63/280,774), as applied respectively to claims 1 and 13 above, and further in view of Drnevich (U.S. 2010/0158792 A1).
Regarding claim 20, modified Lee renders the process of claim 1 obvious, as discussed, wherein the hydrogen product stream is of high purity (Lee, [0032]). While Lee does not explicitly teach that the hydrogen product stream comprises 85 vol.% or greater of hydrogen, Drnevich teaches a similar process of a preliminary CO2 removal step from shifted steam methane reforming syngas followed by pressure swing adsorption producing 99.9 vol.% or greater hydrogen (Drnevich, [0023]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention for Lee’s process to produce 99.9 vol.% or greater hydrogen, as Lee is directed toward producing a high purity hydrogen product (Lee, [0032]), and Drnevich teaches that such a purity is possible to achieve using a similar process to Lee’s (Drnevich, [0023]).
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Lee (U.S. 2015/0233290 A1) in view of Allam (U.S. 2023/0150817 A, effectively filed November 18th, 2021 by virtue of U.S. Provisional Application 63/280,774), as applied respectively to claims 1 and 13 above, and further in view of Subbaraman (U.S. 2019/0112188 A1).
Regarding claim 21, modified Lee renders the process of claim 1 obvious, as discussed above, wherein the fuel for the gas turbine is a combination of two or more selected from a list including hydrogen and natural gas (Lee, [0023]). Subbaraman teaches that a fuel blend of natural gas and hydrogen comprising 75% hydrogen is a suitable fuel for a hydrogen turbine (Subbaraman, [0064]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have selected a blend of hydrogen and natural gas having 75 vol.% hydrogen as the fuel in Lee’s hydrogen turbine. The selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. See In re Leshin, 125 USPQ 416 (CCPA 1960), Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945), and MPEP § 2144.07. In the instant case, Lee acknowledged a hydrogen-natural gas blend as a suitable fuel (Lee, [0023]), and Subbaraman teaches that a blend having 75 vol.% is suitable for this purpose (Subbaraman, [0064]; [0019]-[0020] indicate that purities are given in vol.%).
Allowable Subject Matter
Claims 3, 9, 18, and 22 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is an examiner’s statement of reasons for indicating allowable subject matter: Fiaschi (The recuperative auto thermal reforming and recuperative reforming gas turbine power cycles with CO2 removal – Part II: The recuperative reforming cycle”, 2004), Drnevich (U.S. 2010/0158792 A1), (U.S. 2023/0147136 A1, filed April 23rd, 2022), Ravikumar (U.S. 2022/0267147 A1, filed 2-22-22; US Prov’l Appl’n filed 2-22-21), Lee (U.S. 2015/0233290 A1), Wynn (U.S. 2012/0141367 A1), Subbaraman (U.S. 2019/0112188 A1), and Allam (U.S. 2023/0150817 A, effectively filed November 18th, 2021 by virtue of U.S. Provisional Application 63/280,774) are considered to be the closest prior art to the instant claims.
Regarding claim 3, modified Lee renders the process of claim 1 obvious, as discussed above, but does not teach or suggest that the undesirable components adsorbed in the pressure-swing adsorption process are directed to the steam methane reformer for further processing after desorption. Lee teaches that recycling methane tail gas by combustion for the steam reforming step uses exergy that is used to generate power in Lee’s process (Lee, [0003]-[0004]). Directing the desorbed undesirable gas to the steam methane reformer for further processing would therefore break the principle of Lee’s process of producing hydrogen while generating power and would not be obvious to incorporate.
Regarding claims 9, 18, and 22, modified Lee renders the process of claim 1 and those features shared between claims 1 and 22 obvious, as discussed above. However, none of the cited prior art references teach or suggest modifying Lee so that at least a portion of steam is introduced into the hydrogen-fueled gas turbine as a diluent. Among the cited prior art references, Fiaschi teaches injecting steam into a hydrogen turbine combustion chamber (Fiaschi, Page 63, Col. 2, Paragraph 3), which constitutes using steam as a diluent, but this is incidental to Fiaschi’s main purpose of steam-cooling the turbine blades. There is no explicit or implicit motivation in Fiaschi to modify a different process using a hydrogen-fueled gas turbine by using steam as a diluent.
Additionally, as Applicant points out on Page 9, line 1 - Page 11, line 18 of Remarks, Filed July 15th, 2026, Fiaschi’s process recycles all hydrogen produced and is focused on maximizing the efficiency of power generation. Indeed, Fiaschi does not have any hydrogen outputs (Fiaschi, Fig. 1), and is principally concerned with efficiency and CO2 removal of power generation, rather than hydrogen production (Fiaschi, Abstract). As a power cycle engineered for heat recuperation and CO2 capture, further modifying Fiaschi such that a second portion of the hydrogen product stream is recovered as a hydrogen product, as claimed, would alter Fiaschi’s process such that a person having ordinary skill in the art would not have a reasonable expectation of maintaining its efficiency and CO2 removal values.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ZACHARY J. BAUM whose telephone number is (571)270-0895. The examiner can normally be reached Monday-Friday 8:30-5:00.
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/ZACHARY JOHN BAUM/Examiner, Art Unit 1736
/ANTHONY J ZIMMER/Supervisory Patent Examiner, Art Unit 1736
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