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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 15 June 2026 has been entered.
Response to Arguments
Applicant’s amendments to independent claims 1, 11, and 18 reciting additional claim limitations relating to the heat being recovered directly from a fluid produced by the first electrolysis subsystem are sufficient to overcome the prior grounds of rejection because the prior art (Bourgeois) taught recovery of the waste heat into a coolant (i.e. not a fluid produced by the first electrolysis subsystem). However, upon further search and consideration, a new ground of rejection is made in view of references already of record and Siecker et al (“Optimal heat recovery during polymer electrolyte membrane electrolysis”).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-4, 6, 11, 12, 14, and 18-24 are rejected under 35 U.S.C. 103 as being unpatentable over Rueger et al (US 2018/0287179 A1) in view of Bourgeois (US 2006/0053792 A1) and Siecker et al (“Optimal heat recovery during polymer electrolyte membrane electrolysis”), with evidence from Vince (US 2016/0230311 A1) for claims 23 and 24 only.
Regarding claim 1, Rueger et al teach (see abstract, figs. 1, 3 and 6, paragraphs [0081]-[0089] and [0108]-[0124]) a system comprising a second water electrolysis subsystem (16 in figs. 1 and 3) that electrolyzes water (as steam) to produce hydrogen, a thermal store (heat accumulator 40 in fig. 3) configured to provide a buffer of thermal energy produced by another process, and a heat pump (64) positioned downstream from the thermal store that receives a heat exchange fluid (low temperature heat source 54 in fig. 6) and generates steam (1 in fig. 6), wherein the second water electrolysis subsystem (16) utilized the steam generated via the heat pump to produce hydrogen by electrolysis of the steam.
Rueger et al fail to teach that (1) the system included a first water electrolysis subsystem that electrolyzed water to produce hydrogen and waste thermal energy, and, (2) (a) the source of the waste thermal energy in the thermal store was the first water electrolysis subsystem, in particular (b) one of the fluids produced by the first water electrolysis subsystem.
Regarding (1) and (2)(a), Bourgeois teaches (see abstract, paragraphs [0013]-[0014] and [0018]) a system comprising a first water electrolysis subsystem (including electrolyzer 38) that electrolyzed water to produce hydrogen while also producing waste thermal energy that was utilized for pre-heating water sent to a boiler for conversion to steam. One of ordinary skill in the art at the time of filing would have recognized the advantage of the system of Bourgeois as using the waste heat from the electrolysis subsystem for a useful purpose instead of having to shed the excess heat to the ambient environment.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have added the first water electrolysis subsystem of Bourgeois to the system of Rueger et al as the source of waste thermal energy used to generate steam because Bourgeois teaches using the waste thermal energy produced by the first water electrolysis subsystem to help generate steam and the combination would have increased the amount of hydrogen being produced by the system.
Regarding (2)(b), Siecker et al teach (see abstract, fig. 1, Proposed hydrogen PEMWE water heating system on page 32694 and Conclusions and recommendations on page 32705) recovering heat produced by a PEM water electrolyzer (i.e. the same type of electrolyzer taught by Bourgeois) directly from the water stream leaving the electrolyzer. The water accumulated in a hot water storage tank and this hot water was utilized as thermal energy for other purposes (such as residential heating). Siecker et al teach (see abstract) that the advantage of recovery of the heat in a hot water storage tank was that it permitted maximum het recovery while ensuring sufficient hydrogen is being produced.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have recovered the waste thermal heat produced by the first electrolysis subsystem taught by Bourgeois from the hot water leaving the anode of the first electrolysis subsystem as suggested by Siecker et al for the purpose of maximizing the heat recovery while ensuring sufficient hydrogen production by the PEM electrolyzer.
Regarding claims 2-4, the first electrolysis subsystem of Bourgeois and Siecker et al was a low-temperature electrolysis technology, such as PEM or alkaline electrolyzer and the second electrolysis subsystem of Rueger et al was a high-temperature electrolysis technology, i.e. a solid oxide electrolysis cell.
Regarding claim 6, Bourgeois teaches (see fig. 4, paragraph [0023]) providing an additional source of heat (flame of boiler 26) that further raises the temperature of the water that extracted the waste thermal energy from the first water electrolysis subsystem. It would have been obvious to one of ordinary skill in the art to have provided this boiler in the combined system to make up any missing thermal energy needed for generating the steam to be sent to the second water electrolysis subsystem.
Regarding claim 23, Rueger et al teach the second water electrolysis subsystem being a solid oxide electrolysis cell (abstract), the steam being generated/stored at a pressure under 20 bar (paragraphs [0045]-[0046]), and the input temperature of the heat pump being less than 100°C (paragraph [0035]). Bourgeois teaches the first water electrolysis subsystem being a PEM water electrolysis system (paragraph [0018]) and providing a boiler (26 in fig. 2) to provide the missing thermal energy necessary for converting the water heated by the waste thermal energy to steam.
Rueger et al and Bourgeois fail to expressly disclose the temperatures of operation of the electrolysis subsystems. Rueger et al fail to teach the output temperature of the heat pump. Rueger et al and Bourgeois fail to teach the temperature and pressure of the steam being generated.
Vince teaches (see paragraph [0026]) that the solid oxide electrolysis cells operated at 500-850°C and (see paragraph [0027]) that the PEM electrolysis cells operated at 50-100°C.
Thus, the solid oxide electrolysis cell and PEM technologies of Rueger et al and Bourgeois inherently operated at the claimed temperature ranges.
It would have been within the ordinary level of skill in the art to perform routine experimentation to determine a suitable output temperature of the heat pump of Rueger et al for balancing the energy needs of the heat pump and boiler.
It would have been within the ordinary level of skill in the art to perform routine experimentation to determine a suitable temperature and pressure of the steam output by the boiler of Bourgeois for feeding into the solid oxide electrolysis cell of Rueger et al.
The prior art teaches the general conditions of the claimed system, and the specific values of temperature and pressure would have been expected by one of ordinary skill in the art to function in the same manner as the prior art system. Applicant has not presented objective evidence that the claimed ranges produce a result different from the prior art.
Regarding claim 11, Rueger et al teach (see abstract, figs. 1, 3 and 6, paragraphs [0081]-[0089] and [0108]-[0124]) a method comprising performing a second type of electrolysis which produced a second hydrogen stream utilizing steam generated from waste thermal energy, buffering, via a steam accumulator (heat accumulator 40 in fig. 3), the waste thermal energy, recovering the waste thermal energy (54) into a heat exchange fluid (refrigerant flowing in the heat pump circuit), receiving, via a heat pump positioned downstream from the steam accumulator, the heat exchange fluid and generating steam using the heat pump, utilizing, via the second type of electrolysis, the steam generated via the heat pump to electrolyze water and produce the second hydrogen stream.
Rueger et al fail to teach that (1) the method included a first type water electrolysis subsystem that electrolyzed water to produce hydrogen and waste thermal energy, (2) concurrently performing the first and second types of water electrolysis, and, (3)(a) recovering the waste thermal energy from the first type of electrolysis (b) from at least one of the fluids produced by the first type of electrolysis.
Regarding (1) and (3)(a), Bourgeois teaches (see abstract, paragraphs [0013]-[0014] and [0018]) a method comprising conducting a first type of water electrolysis (including electrolyzer 38) that electrolyzed water to produce hydrogen while also producing waste thermal energy that was utilized for pre-heating water sent to a boiler. One of ordinary skill in the art at the time of filing would have recognized the advantage of the system of Bourgeois by using the waste heat from the electrolysis subsystem for a useful purpose instead of having to shed the excess heat to the ambient environment.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have added the first type of water electrolysis of Bourgeois to the system of Rueger et al as the source of waste thermal energy used to generate steam because Bourgeois teaches using the waste thermal energy produced by the first water electrolysis subsystem to help generate steam.
Regarding (3)(b), Siecker et al teach (see abstract, fig. 1, Proposed hydrogen PEMWE water heating system on page 32694 and Conclusions and recommendations on page 32705) recovering heat produced by a PEM water electrolyzer (i.e. the same type of electrolyzer taught by Bourgeois) directly from the water stream leaving the electrolyzer. The water accumulated in a hot water storage tank and this hot water was utilized as thermal energy for other purposes (such as residential heating). Siecker et al teach (see abstract) that the advantage of recovery of the heat in a hot water storage tank was that it permitted maximum het recovery while ensuring sufficient hydrogen is being produced.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have recovered the waste thermal heat produced by the first electrolysis subsystem taught by Bourgeois from the hot water leaving the anode of the first electrolysis subsystem as suggested by Siecker et al for the purpose of maximizing the heat recovery while ensuring sufficient hydrogen production by the PEM electrolyzer.
Regarding (2), Rueger et al teach operation of the second type of electrolysis while the waste thermal energy process is running and Bourgeois teaches operation of the first type of electrolysis while the waste thermal energy is used to generate steam in boiler 108. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing that both electrolysis types could have been operated at the same time with the production of steam being a “bridge” between the two processes.
Regarding claims 12 and 21-22, the first electrolysis subsystem of Bourgeois and Siecker et al was a low-temperature electrolysis technology, such as PEM or alkaline electrolyzer and the second electrolysis subsystem of Rueger et al was a high-temperature electrolysis technology, i.e. a solid oxide electrolysis cell.
Regarding claim 14, Bourgeois teaches (see fig. 4, paragraph [0023]) providing an additional heating step (flame of boiler 108) that further raises the temperature of the water that extracted the waste thermal energy from the first water electrolysis subsystem. It would have been obvious to one of ordinary skill in the art to have provided this boiler in the combined method to make up any missing thermal energy needed for generating the steam to be sent to the second water electrolysis subsystem.
Regarding claim 24, Rueger et al teach the second water electrolysis type is a solid oxide electrolysis cell (abstract), the steam being generated/stored at a pressure under 20 bar (paragraphs [0045]-[0046]), the input temperature of the heat pump being less than 100°C (paragraph [0035]), and venting the oxygen and storing the hydrogen from the solid oxide electrolysis cell (paragraphs [0084] and [0089]). Bourgeois teaches the first water electrolysis subsystem being a PEM water electrolysis system (paragraph [0018]) and providing a boiler (26 in fig. 2) to provide the missing thermal energy necessary for converting the water heated by the waste thermal energy to steam.
Rueger et al and Bourgeois fail to expressly disclose the temperatures of operation of the electrolysis subsystems. Rueger et al fail to teach the output temperature of the heat pump. Rueger et al and Bourgeois fail to teach the temperature and pressure of the steam being generated.
Vince teaches (see paragraph [0026]) that the solid oxide electrolysis cells operated at 500-850°C and (see paragraph [0027]) that the PEM electrolysis cells operated at 50-100°C.
Thus, the solid oxide electrolysis cell and PEM technologies of Rueger et al and Bourgeois inherently operated at the claimed temperature ranges.
It would have been within the ordinary level of skill in the art to perform routine experimentation to determine a suitable output temperature of the heat pump of Rueger et al for balancing the energy needs of the heat pump and boiler.
It would have been within the ordinary level of skill in the art to perform routine experimentation to determine a suitable temperature and pressure of the steam output by the boiler of Bourgeois for feeding into the solid oxide electrolysis cell of Rueger et al.
The prior art teaches the general conditions of the claimed system, and the specific values of temperature and pressure would have been expected by one of ordinary skill in the art to function in the same manner as the prior art system. Applicant has not presented objective evidence that the claimed ranges produce a result different from the prior art.
Regarding claim 18, Rueger et al teach (see abstract, figs. 1, 3 and 6, paragraphs [0081]-[0089] and [0108]-[0124]) a system comprising a second water electrolysis subsystem (16 in figs. 1 and 3) that electrolyzes water (as steam) to produce hydrogen, a thermal store (heat accumulator 40 in fig. 3) configured to provide a buffer of thermal energy produced by another process, a heat pump (64) positioned downstream from the thermal store that receives a heat exchange fluid (low temperature heat source 54 in fig. 6) and generates steam (1 in fig. 6), wherein the second water electrolysis subsystem (16) utilized the steam generated via the heat pump to produce hydrogen by electrolysis of the steam.
Rueger et al fail to teach that (1) the system included a first water electrolysis subsystem that electrolyzed water to produce hydrogen and waste thermal energy, and (2)(a) the source of the waste thermal energy in the thermal store was the first water electrolysis subsystem, (b) specifically one of the fluids produced by the first water electrolysis subsystem.
Regarding (1) and (2)(a), Bourgeois teaches (see abstract, paragraphs [0013]-[0014] and [0018]) a system comprising a first water electrolysis subsystem (including electrolyzer 38) that electrolyzed water to produce hydrogen while also producing waste thermal energy that was utilized for pre-heating water sent to a boiler. One of ordinary skill in the art at the time of filing would have recognized the advantage of the system of Bourgeois by using the waste heat from the electrolysis subsystem for a useful purpose instead of having to shed the excess heat to the ambient environment.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have added the first water electrolysis subsystem of Bourgeois to the system of Rueger et al as the source of waste thermal energy used to generate steam because Bourgeois teaches using the waste thermal energy produced by the first water electrolysis subsystem to help generate steam.
Regarding (2)(b), Siecker et al teach (see abstract, fig. 1, Proposed hydrogen PEMWE water heating system on page 32694 and Conclusions and recommendations on page 32705) recovering heat produced by a PEM water electrolyzer (i.e. the same type of electrolyzer taught by Bourgeois) directly from the water stream leaving the electrolyzer. The water accumulated in a hot water storage tank and this hot water was utilized as thermal energy for other purposes (such as residential heating). Siecker et al teach (see abstract) that the advantage of recovery of the heat in a hot water storage tank was that it permitted maximum het recovery while ensuring sufficient hydrogen is being produced.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have recovered the waste thermal heat produced by the first electrolysis subsystem taught by Bourgeois from the hot water leaving the anode of the first electrolysis subsystem as suggested by Siecker et al for the purpose of maximizing the heat recovery while ensuring sufficient hydrogen production by the PEM electrolyzer.
Regarding claims 19-20, the first electrolysis subsystem of Bourgeois and Siecker et al was a low-temperature electrolysis technology, such as PEM or alkaline electrolyzer and the second electrolysis subsystem of Rueger et al was a high-temperature electrolysis technology, i.e. A solid oxide electrolysis cell.
Conclusion
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/HARRY D WILKINS III/Primary Examiner, Art Unit 1794
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