Prosecution Insights
Last updated: April 18, 2026
Application No. 18/344,906

HYBRID LOW-HIGH TEMPERATURE ELECTROLYSIS WITH HEAT RECOVERY

Final Rejection §102§103
Filed
Jun 30, 2023
Examiner
WILKINS III, HARRY D
Art Unit
1794
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Schlumberger Technology Corporation
OA Round
2 (Final)
62%
Grant Probability
Moderate
3-4
OA Rounds
2y 11m
To Grant
81%
With Interview

Examiner Intelligence

Grants 62% of resolved cases
62%
Career Allow Rate
679 granted / 1087 resolved
-2.5% vs TC avg
Strong +19% interview lift
Without
With
+18.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 11m
Avg Prosecution
43 currently pending
Career history
1130
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
49.6%
+9.6% vs TC avg
§102
21.3%
-18.7% vs TC avg
§112
17.4%
-22.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1087 resolved cases

Office Action

§102 §103
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 . 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 1-4, 7, 11, 12, 15, and 18-20 are rejected under 35 U.S.C. 102(a)(2) as being clearly anticipated by Klein et al (WO 2023/158433). Regarding claims 1 and 11, see Klein et al at abstract, fig. 1, and page 9. The system and method of Klein et al utilized a “low-temperature” electrolysis system (120) which produced heat (d) and transferring the heat (d) from the “low-temperature” electrolysis system (120) to a “high-temperature” electrolysis system (170) by pre-heating water (c) in a vaporizer (160) where the resulting steam is the feedstock to the “high-temperature” electrolysis system (170). Both electrolysis systems concurrently electrolyze water (as either liquid water or steam) to produce hydrogen gas. Regarding claim 18, Klein et al, as discussed above, teach a system including a low-temperature water electrolysis subsystem (120) that electrolyzed water to produce hydrogen and produce waste thermal energy (d) and a high-temperature water electrolysis subsystem (170) that also electrolyzed water to produce hydrogen, wherein the high-temperature water electrolysis subsystem utilized the waste thermal energy (d) produced by the low-temperature water electrolysis subsystem (120). Regarding claims 3 and 19, the “low-temperature” electrolysis system (120) of Klein et al was (see last paragraph of page 3) a PEM cell, AEM cell or alkaline electrolysis cell. Regarding claims 4 and 20, the “high-temperature” electrolysis system (170) of Klein et al was (see first paragraph of page 4) a solid oxide electrolyzer cell. Regarding claims 7 and 15, Klein et al teach using the heat extracted from the “low-temperature” electrolysis system (120) to generate steam. Regarding claim 12, the “low-temperature” electrolysis system (120) of Klein et al was (see last paragraph of page 3) a PEM cell, AEM cell or alkaline electrolysis cell and the “high-temperature” electrolysis system (170) of Klein et al was (see first paragraph of page 4) a solid oxide electrolyzer cell. 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 1-7, 11-15 and 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Bourgeois (US 2006/0053792) in view of Peter et al (US 2009/0139874). Bourgeois teaches (see abstract, fig. 1, 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 a pre-heating water sent to a boiler. Bourgeois fails to teach a second water electrolysis subsystem that utilized the waste thermal energy produced by the first water electrolysis subsystem. Peter et al teach (see abstract, fig. 1, paragraphs [0024]-[0027]) a second water electrolysis subsystem (10) that electrolyzed water to produce hydrogen while utilizing waste thermal energy produced by a separate subsystem (103). Peter et al teach that electrolysis of steam (gaseous water) uses less electricity input than electrolysis of liquid water. Therefore, it would have been obvious to have combined the two water electrolysis subsystems of Bourgeois and Peter et al into a single combination by using the waste thermal energy produced by Bourgeois as the thermal energy input (103) of Peter et al to improve the energy efficiency of the electrolysis subsystem of Peter et al while also providing a useful end for the waste thermal energy of Bourgeois. Regarding claims 2-4, Bourgeois teaches (see paragraph [0018]) the first electrolysis subsystem being a PEM or alkaline electrolyzer, i.e. a “low-temperature electrolysis technology”, and Peter et al teach (see abstract) the second electrolysis subsystem being a solid oxide electrolysis cell, i.e. a “high-temperature electrolysis technology”. Regarding claim 5, Bourgeois teach extracting the waste thermal energy of the first water electrolysis subsystem into a heat exchange fluid (cooling water). Regarding claim 6, Bourgeois teach using the heat exchange fluid in a heater (24) to increase the temperature of the heat exchange fluid. This generated steam. Peter et al teach using steam generated from waste thermal energy to perform electrolysis at reduced electrical input costs. Regarding claim 7, Bourgeois and Peter et al both teach using waste thermal energy to boil water to generate steam. Peter et al teach utilizing the steam in the second water electrolysis subsystem. Regarding claim 11, as above, Bourgeois teaches a method comprising performing a first type of electrolysis that produced hydrogen and waste thermal energy, the waste thermal energy being fed to a steam generation step. Bourgeois fails to teach a step of concurrently using a second type of electrolysis that utilized the waste thermal energy produced by the first water electrolysis. Peter et al teaches a method comprising performing a second type of electrolysis that produced hydrogen and utilized waste thermal energy for steam generation. The electrolysis of steam utilized less electricity than electrolysis of water. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have combined the different electrolysis technologies of Bourgeois and Peter et al to achieve the effect of utilizing the waste thermal energy produced by Bourgeois as an energy input in the process of Peter et al in order to maximize the efficiency of electrolysis. Regarding claim 12, Bourgeois teaches (see paragraph [0018]) the first electrolysis subsystem being a PEM or alkaline electrolyzer, i.e. a “low-temperature electrolysis technology”, and Peter et al teach (see abstract) the second electrolysis subsystem being a solid oxide electrolysis cell, i.e. a “high-temperature electrolysis technology”. Regarding claim 13, Bourgeois teach extracting the waste thermal energy of the first water electrolysis subsystem into a heat exchange fluid (cooling water). Regarding claim 14, Bourgeois teach using the heat exchange fluid in a heater (24) to increase the temperature of the heat exchange fluid. This generated steam. Peter et al teach using steam generated from waste thermal energy to perform electrolysis at reduced electrical input costs. Regarding claim 15, Bourgeois and Peter et al both teach using waste thermal energy to boil water to generate steam. Peter et al teach utilizing the steam in the second water electrolysis subsystem. Regarding claims 18-20, Bourgeois teaches (see abstract, fig. 1, 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 a pre-heating water sent to a boiler. Bourgeois teaches (see paragraph [0018]) the first electrolysis subsystem being a PEM or alkaline electrolyzer, i.e. a “low-temperature electrolysis technology”, Bourgeois fails to teach a second water electrolysis subsystem that utilized the waste thermal energy produced by the first water electrolysis subsystem. Peter et al teach (see abstract, fig. 1, paragraphs [0024]-[0027]) a second water electrolysis subsystem (10) that electrolyzed water to produce hydrogen while utilizing waste thermal energy produced by a separate subsystem (103). Peter et al teach that electrolysis of steam (gaseous water) uses less electricity input than electrolysis of liquid water. Peter et al teach (see abstract) the second electrolysis subsystem being a solid oxide electrolysis cell, i.e. a “high-temperature electrolysis technology”. Therefore, it would have been obvious to have combined the two water electrolysis subsystems of Bourgeois and Peter et al into a single combination by using the waste thermal energy produced by Bourgeois as the thermal energy input (103) of Peter et al to improve the energy efficiency of the electrolysis subsystem of Peter et al while also providing a useful end for the waste thermal energy of Bourgeois. Claims 5, 6, 13, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Klein et al (WO 2023/158433) as applied to claims 1 and 11 above, and further in view of Bourgeois (US 2006/0053792). Regarding claims 5 and 13, Klein et al is silent on how the waste thermal energy is transferred from the first electrolysis subsystem/step to the second electrolysis subsystem/step. Bourgeois teaches (see abstract, fig. 1, 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 a pre-heating water sent to a boiler. Bourgeois teach extracting the waste thermal energy of the first water electrolysis subsystem into a heat exchange fluid (cooling water) and feeding the heat exchange fluid to the steam boiler. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have used a heat exchange fluid (cooling water) as taught by Bourgeois to transfer the waste thermal energy of Klein et al to the second electrolysis subsystem since Klein et al is silent on the particulars of how the waste thermal energy was transferred and Bourgeois shows a known mechanism for performing the transfer of waste thermal energy in the same context (extracting heat from a water electrolysis cell to a steam boiler). Regarding claims 6 and 14, Bourgeois teach using the heat exchange fluid in a heater (24) to increase the temperature of the heat exchange fluid. This generated steam. Peter et al teach using steam generated from waste thermal energy to perform electrolysis at reduced electrical input costs. Claims 8-10 and 16-17 are rejected under 35 U.S.C. 103 as being unpatentable over Klein et al (WO 2023/158433) OR Bourgeois (US 2006/0053792) in view of Peter et al (US 2009/0139874) as applied to claims 1 and 11 above, and further in view of Rueger et al (US 2018/0287179). None of Klein et al, Bourgeois and Peter et al teach buffering waste thermal energy utilizing a thermal store. Rueger et al teach (see abstract, fig. 1, paragraphs [0042]-[0043]) a solid oxide electrolysis cell system that included a thermal buffer, such as a steam accumulator, to permit storage of thermal energy for use at a later time for balancing out different load steps and bridging the time between production and use. Therefore, it would have been obvious to one of ordinary skill in the art to have added a steam accumulator as taught by Rueger et al to the systems of Klein et al OR Bourgeois as modified by Peter et al for the purpose of balancing out different load steps and bridging the time between production and use of the steam. With respect to the limitations of claims 9 and 10, note that the steam accumulator must be downstream of the heater, where the steam is generated. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to HARRY D WILKINS III whose telephone number is (571)272-1251. The examiner can normally be reached M-F 9:30am -6:00pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, James Lin can be reached at 571-272-8902. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /HARRY D WILKINS III/Primary Examiner, Art Unit 1794
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Prosecution Timeline

Jun 30, 2023
Application Filed
Jan 21, 2026
Non-Final Rejection — §102, §103
Feb 13, 2026
Interview Requested
Feb 20, 2026
Examiner Interview Summary
Feb 20, 2026
Applicant Interview (Telephonic)
Mar 10, 2026
Response Filed
Apr 10, 2026
Final Rejection — §102, §103 (current)

Precedent Cases

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
62%
Grant Probability
81%
With Interview (+18.7%)
2y 11m
Median Time to Grant
Moderate
PTA Risk
Based on 1087 resolved cases by this examiner. Grant probability derived from career allow rate.

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