Prosecution Insights
Last updated: April 19, 2026
Application No. 19/249,867

THERMAL ENERGY STORAGE SYSTEM COUPLED TO A SOLID OXIDE SYSTEM AND A THERMAL CASCADE HEAT EXCHANGER

Non-Final OA §102§103
Filed
Jun 25, 2025
Examiner
MENDEZ, ZULMARIAM
Art Unit
1794
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Rondo Energy Inc.
OA Round
1 (Non-Final)
66%
Grant Probability
Favorable
1-2
OA Rounds
3y 2m
To Grant
88%
With Interview

Examiner Intelligence

Grants 66% — above average
66%
Career Allow Rate
612 granted / 933 resolved
+0.6% vs TC avg
Strong +22% interview lift
Without
With
+22.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
36 currently pending
Career history
969
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
59.6%
+19.6% vs TC avg
§102
23.8%
-16.2% vs TC avg
§112
10.4%
-29.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 933 resolved cases

Office Action

§102 §103
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 . Election/Restrictions Applicant's election with traverse of Group I, encompassing claims 1-10,17,19-21,23-25,27-29,33-37 and 44-45, in the reply filed on January 9, 2026 is acknowledged. The traversal is on the ground(s) that a search for claim 1 would necessarily uncover prior art relevant to claims 11 and 38, and there would not be a significant search burden to examine all claims together. This is not found persuasive because the inventions are divergent subject matter as shown by their difference in classification. Additionally, different inventive concepts require different search queries and considerations. The requirement is still deemed proper and is therefore made FINAL. 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)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claims 1-10, 19-21, 23-25, 27-29 and 33-37 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by O’Donnell et al. (US Patent Application Publication no. 2022/0170386). Regarding claim 1, O’Donnell discloses a solid oxide electrolysis system (paragraphs 46; 716-718), including: a thermal energy storage (TES) system configured to store thermal energy in a storage medium (paragraphs 12, 15), the thermal energy being generated by conversion of input electricity from an energy source (paragraphs 2, 12, 46, 151); a solid oxide (SO) unit (5007; paragraphs 46, 716-718; figures 80, 86); a steam cycle system (paragraph 715; figures 80, 86) including: a first heat exchanger configured to use thermal energy from the TES (R6; paragraphs 715-716, 754-755) to heat input steam at a first pressure and to provide the input steam to a steam turbine (paragraphs 715, 756, 798); and a second heat exchanger (the steam downstream of the steam turbine may exchange heat an additional time. Multiple heat exchangers may be added, and may be varied to have more of fewer stages as a matter of design choice; paragraphs 715, 770); the second heat exchanger is configured to use thermal energy from the TES to heat extracted steam from the steam turbine at a second pressure that is lower than the first pressure, and to direct the heated extracted steam as an input to the solid oxide unit (implementations are possible and contemplated in which steam is received by the turbine at a first pressure and is output therefrom at a second, lower pressure, with lower pressure steam being recirculated in the cycle. The heated steam is directed as an input to the SO unit; paragraphs 715-718, 756, 770-771). It is important to note that apparatus claims must be distinguished from the prior art in terms of structure rather than function. Functional limitations do not serve to further limit apparatus claims beyond imparting the limitation that the device is capable of performing a claimed function. If the prior art structure is capable of performing the intended use, then it meets the claim. Regarding claim 2, the first heat exchanger of O’Donnell is configured as a first superheater (paragraphs 188, 724-725). Regarding claim 3, the second heat exchanger of O’Donnell is configured as a second superheater (paragraphs 188, 724-725). Regarding claim 4, the SO unit of O’Donnell is configured to receive thermal energy directly from the TES (paragraphs 716-718). Regarding claim 5, O’Donnell further teaches wherein the steam cycle system further includes a third heat exchanger configured to heat output steam extracted from the steam turbine produce additional input steam using thermal energy recovered from the SO unit and/or thermal energy from the TES, and circulate the heated output steam as an input to the SO unit (paragraphs 715-718, 756, 770, 798, 866). Regarding claim 6, the system of O’Donnell includes an additional heat exchanger configured to use thermal energy from the TES to further heat output steam from the steam turbine and to provide the further heated output steam as an input to the SO unit (paragraphs 715-718, 756, 770, 798, 866). Regarding claim 7, the TES system of O’Donnell is configured to provide thermal energy to maintain the SO unit within an acceptable operating temperature range during both an electrolysis mode and a standby mode of the SO unit (paragraphs 29, 716-718, 751). Regarding claim 8, the steam turbine of O’Donnell is configured to drive a generator, and the system is further configured to return at least a portion of the electrical energy produced by the generator as input electrical energy to the SO unit and/or to the TES system based on one or more predetermined parameters (paragraphs 697, 712, 715, 798). Regarding claim 9, the first heat exchanger of O’Donnell is configured to heat the input steam to a temperature between about 600°C and 700°C (paragraph 754 - the solid oxide unit is maintained at a desired temperature). It is important to note that apparatus claims must be distinguished from the prior art in terms of structure rather than function. Functional limitations do not serve to further limit apparatus claims beyond imparting the limitation that the device is capable of performing a claimed function. If the prior art structure is capable of performing the intended use, then it meets the claim. Regarding claim 10, O’Donnell suggests wherein the second heat exchanger is configured to heat the extracted steam to a temperature between about 650°C and 1100°C (paragraphs 716, 763 – the solid oxide unit is maintained at a desired temperature). It is important to note that apparatus claims must be distinguished from the prior art in terms of structure rather than function. Functional limitations do not serve to further limit apparatus claims beyond imparting the limitation that the device is capable of performing a claimed function. If the prior art structure is capable of performing the intended use, then it meets the claim. Regarding claim 19, the steam turbine of O’Donnell is a condensing steam turbine and further including a condenser configured to condense the output steam from the condensing steam turbine into a liquid (paragraphs 752, 758). Regarding claim 20, O’Donnell discloses wherein the energy source is a renewable energy source having intermittent availability (abstract; paragraphs 6, 164, 781). Regarding claim 21, the first heat exchanger (5005; figure 86) and the second heat exchanger (5013) of O’Donnell are part of a thermal cascade and sequentially receive the thermal energy from the TES (5001; paragraphs 754-755). Regarding claim 23, the system of O’Donnell is configured to provide a heated output steam at a temperature between about 650°C and 1100°C (paragraphs 716, 763 – the solid oxide unit is maintained at a desired temperature). It is important to note that apparatus claims must be distinguished from the prior art in terms of structure rather than function. Functional limitations do not serve to further limit apparatus claims beyond imparting the limitation that the device is capable of performing a claimed function. If the prior art structure is capable of performing the intended use, then it meets the claim. Regarding claim 24, the system of O’Donnell further includes a condenser (paragraph 708) wherein the condenser and the additional heat exchanger define a steam loop; and the second heat exchanger is configured to superheat working fluid extracted from the steam loop to form the heated output steam (paragraphs 769-775). Regarding claim 25, the at least one additional heat exchanger of O’Donnell includes at least a power steam superheater, an evaporator, and an economizer (paragraphs 188, 711-712). Regarding claim 27, the second heat exchanger of O’Donnell is configured to provide the TES thermal energy by convective heat transfer (paragraphs 415, 678, 841). Regarding claim 28, the second heat exchanger of O’Donnell is configured to provide the TES thermal energy by radiative heat transfer (paragraphs 408, 415, 841). Regarding claim 29, the system of O’Donnell further includes a blower configured for directing a heat transfer fluid that has passed through the thermal cascade heat exchange assembly back to the TES (paragraphs 277, 689). Regarding claim 33, the steam turbine of O’Donnell is a non-condensing steam turbine (paragraphs 712, 715, 756, 816). Regarding claim 34, each of the heat exchangers of O’Donnell is configured to maintain a desired temperature (paragraphs 715-718, 754, 756, 770, 798, 866). It has been held by courts that generally, differences in temperature do not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such temperature is critical. Where 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 reAller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05.II.A. Regarding claim 35, the processed output working fluid of O’Donnell includes pressurized, heated steam at a temperature in an operating range of temperatures acceptable for an electrolysis mode of the SO unit (paragraphs 715-718, 754, 756, 770, 798, 866). Regarding claim 36, the processed output of O’Donnell includes pressurized, heated steam at a temperature in an operating range of temperatures acceptable for a standby mode of the SO unit (paragraphs 715-718, 751, 754, 756, 770, 798, 866). Regarding claim 37, the storage medium of O’Donnell includes a refractory material (paragraphs 10-11, 26). 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 non-obviousness. Claims 17, 44 and 45 are rejected under 35 U.S.C. 103 as being unpatentable over O’Donnell as applied to claims 1 and 5 above, and further in view of Klemencic (US Patent Application Publication no. 2013/0056170). Regarding claims 17, 44 and 45, O’Donnell teaches all the features discussed above, wherein three heat exchangers are provided to produce additional input steam using thermal energy recovered from the SO unit and/or thermal energy from the TES, and circulate the heated output steam as an input to the SO unit (paragraphs 715-718, 756, 770, 798, 866). O’Donnell fails to explicitly teach wherein the first, second, third and fourth heat exchangers form a cascade and sequentially receive the thermal energy from the TES. Klemencic discloses a system comprising a thermal energy storage module including a cascade of up to six heat exchangers in order to achieve higher heat transfer rates to improve the temperature profile across the module (paragraph 34). It would have been obvious to one having ordinary skill in the art at the time of filing to include four heat exchangers forming a cascade and sequentially receiving the thermal energy from the TES of O’Donnell, as taught by Klemencic, in order to achieve higher heat transfer rates to improve the temperature profile across the module. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to ZULMARIAM MENDEZ whose telephone number is (571)272-9805. The examiner can normally be reached M-F 8am-4:30p. 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. /ZULMARIAM MENDEZ/Primary Examiner, Art Unit 1794
Read full office action

Prosecution Timeline

Jun 25, 2025
Application Filed
Feb 06, 2026
Non-Final Rejection — §102, §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12601633
Modified Rectangular Wave Polarization Control (MRWPC) System
2y 5m to grant Granted Apr 14, 2026
Patent 12601076
IMPURITY CONTROL IN LITHIUM RECOVERY
2y 5m to grant Granted Apr 14, 2026
Patent 12595574
SYSTEM AND PROCESS FOR ANTHRAQUINONE FUNCTIONALIZATION
2y 5m to grant Granted Apr 07, 2026
Patent 12595575
ELECTROCHEMICAL OXIDATION OF METHANE TOWARDS METHANOL ON MIXED METAL OXIDES
2y 5m to grant Granted Apr 07, 2026
Patent 12590352
AMMONIUM COMPLEX SYSTEM-BASED METHOD FOR SEPARATING AND PURIFYING LEAD, ZINC, CADMIUM, AND COPPER
2y 5m to grant Granted Mar 31, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

1-2
Expected OA Rounds
66%
Grant Probability
88%
With Interview (+22.1%)
3y 2m
Median Time to Grant
Low
PTA Risk
Based on 933 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month