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 .
Election/Restrictions
Applicant's election with traverse of group I, drawn to the method recited in claims 1-18, in the reply filed on 07/31/2026 is acknowledged. The traversal is on the ground(s) that Examiner did not establish a search or examination burden.
Specifically, Applicant argues that because at least a portion of the prior art references applicable to the method invention of group I would likely be applied to the apparatus invention of group II, it cannot reasonably be considered that serious search burden exists.
Examiner respectfully disagrees. At issue is whether there would be a serious search and examination burden were the inventions of groups I and II to be examined together.
In order to establish serious search and examination burden, at least one of the following conditions must be met:
a) the inventions are classified separately or, if classified together, the inventions have a separate subject for inventive effort;
b) a different field of search is required for at least one of the inventions;
c) non-prior art issues are likely to apply to one of the distinct inventions, but not another of the distinct inventions (MPEP § 808.02).
In the instant case, Applicant has argued that Examiner has not demonstrated that condition b) for determining a serious search burden applies to the inventions in question. However, only one of conditions a-c) need be met to establish a serious burden. Applicant has not provided any argument as to why conditions a) and c) do not apply in the instant case. I.e., the inventions as claimed are separately classified, and there is therefore satisfy condition a) for establishing serious search burden. Furthermore, as the inventions are directed to different statutory categories, they are considered likely to raise different non-prior art issues under 35 U.S.C. § 112, and therefore satisfy condition c) for establishing serious examination burden. Thus, even if, in arguendo, Applicant’s argument that condition b) for establishing serious search burden were persuasive, restriction between the inventions of groups I and II would be appropriate.
However, Applicant’s argument is not persuasive. Specifically, the test for serious search burden under condition b) is not whether art applicable to at least one invention is likely to be applicable to the other invention, but whether art applicable to at least one invention is unlikely to be applicable to the other invention (MPEP § 808.2).
In the instant case, the invention of group II is claimed as an apparatus, and is therefore significantly broader in scope than the inventive methods claimed in group I. In particular, prior art directed to thermal energy recovery from electrolytic cells intended to be used for purposes other than co-electrolysis would apply to the invention of group II, but not the invention of group I. Therefore, prior art applicable to the invention of group II is not likely to be applicable to the invention of group I, and a full and complete search of the invention of group I is unlikely to identify the best prior art applicable to the invention of group II. Thus, the inventions of groups I and II require a different field of search, and therefore there exists a clear serious search burden under condition b).
As Applicant has not provided any rationale as to why no serious search burden exists due to the separate classifications of groups I and II, or why no serious examination burden exists under 35 U.S.C. § 112, Applicant’s argument is not persuasive. Furthermore, Applicant’s argument that no different field of search would be required for the inventions of groups I and II is not persuasive, because Applicant has applied an incorrect basis for making this determination.
The requirement is still deemed proper and is therefore made FINAL.
Claims 19-20 withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 07/31/2026.
Claim Interpretation
The term “about” has been defined by Applicant as “±20% of the stated value, ±15% of the stated value, ±10% of the stated value, ±5% of the stated value, ±3% of the stated value, or ±1% of the stated value” in para. 47 of the specification.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 4-11 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Regarding claim 4, claim 4 recites the limitation “a third heat exchanger” in line 2. However, claim 1, from which claim 4 depends, already recites “a third heat exchanger” in line 11. It is therefore unclear whether the recitation of “a third heat exchanger” in claim 4 is intended to refer to “the third heat exchanger”, or is intended to require an additional e.g., sixth, “heat exchanger”.
Claim 4 is therefore indefinite.
Regarding claims 5-8, claims 5-8 depend from claim 4, and therefore incorporate the indefinite language of claim 4.
Claims 5-8 are therefore indefinite.
Regarding claim 9, claim 9 recites the limitation “the third heat exchanger” in line 7. However, claims 1 and 4 each separately recite “a third heat exchanger”. It is therefore unclear to which “third heat exchanger” the limitation “the third heat exchanger” is intended to refer.
Furthermore, claim 9 depends from claim 4, and therefore inherits the indefinite language of claim 4.
Claim 9 is therefore indefinite.
Regarding claim 10, claim 10 recites the limitation “a third heat exchanger” in line 2. However, claim 1, from which claim 10 depends, already recites “a third heat exchanger” in line 11. It is therefore unclear whether the recitation of “a third heat exchanger” in claim 4 is intended to refer to “the third heat exchanger”, or is intended to require an additional e.g., seventh, “heat exchanger”.
Claim 10 is therefore indefinite.
Regarding claim 11, claim 11 recites the limitation “the third heat exchanger” in lines 2-3. However, claims 1 and 10 each separately recite “a third heat exchanger”. It is therefore unclear to which “third heat exchanger” the limitation “the third heat exchanger” is intended to refer.
Furthermore, claim 11 depends from claim 10, and therefore inherits the indefinite language of claim 10.
Claim 11 is therefore indefinite.
Allowable Subject Matter
Claims 1-3 and 12-18 are allowed.
Furthermore, claims 4-11 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
Regarding claim 1, the prior art of record, taken as a whole, does not reasonably teach or render obvious the cumulative limitations of claim 1, taken as a whole.
The closest prior art is considered to be Erharter (WO 2025/039019 A1), Min et al. (“Thermodynamic analysis of a solid oxide co-electrolysis cell system for its optimal thermal integration with external heat supply” Energy Conversion and Management 225 (2020) 113381), Kresnyak (US Pat. Pub. 2024/0247202 A1), Braun (US Pat. Pub. 2014/0272734 A1), and Rueger (US Pat. Pub. 2020/0095124 A1).
Erharter teaches a method comprising:
heating a carbon dioxide (“Cathode gas, in particular carbon dioxide, is supplied to the cathode section via the cathode supply connection” para. 9) feed stream (“cathode supply connection 502” para. 55 and Fig. 4, annotated below) in a first heat exchanger (“seventh heat exchanger 610” para. 57 and Fig. 4) using a first cathode effluent (“cathode discharge connection 600” Id.) from a cathode (“cathode discharge section 114” Id.) of an electrolyzer (“electrolysis cell stack 100” para. 59 and Fig. 4) comprising an anode, a cathode, and an electrolyte inserted between the anode and the cathode (e.g., para. 47) as a heat transfer medium to generate a heated carbon dioxide effluent (“are arranged thermally and thermally coupled to the cathode supply connection 500 in order to transfer heat from the synthesis gas to the cathode gas and thus increase the efficiency of the electrolysis system” para. 57 and Fig. 4),
heating a first steam feed stream (“Water or steam is supplied from the first additional feed connection 702” para. 56 and Fig. 4) in a second heat exchanger using a second cathode effluent from the cathode of the electrolyzer (“sixth heat exchanger 608” para. 57 and Fig. 4) as a heat transfer medium to generate a first heated steam effluent (see Fig. 4),
heating a second steam feed stream (“Water or steam is supplied from the first additional feed connection 702” para. 56 and Fig. 4) in a third heat exchanger (“fourth heat exchanger 314” Id.) using an anode effluent from the anode of the electrolyzer (“located in the anode discharge connection 300” Id.) as a heat transfer medium to generate a second heated steam effluent (see Fig. 4).
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Annotated Erharter Fig. 4
Erharter does not teach combusting, in a combustion unit, a tail gas stream to transfer heat from the combusting to the heated carbon dioxide effluent, the first heated steam effluent, and the second heated steam effluent to generate a heated carbon dioxide and steam stream effluent. Erharter instead teaches the use of an electric heater (“second heating device 506” para. 55 and Fig. 4) for heating the heated carbon dioxide effluent, the first heated steam effluent, and the second heated steam effluent to generate a heated carbon dioxide and steam stream effluent.
However, Min teaches methods for recovering thermal energy in co-electrolysis systems, wherein heat from a combustor (Fig. 2) is used to raise the temperature of a feed stream comprising carbon dioxide and steam to the operating temperature of the electrolyzer in a heat exchanger (“HX5” Fig. 4).
It is therefore considered that a person having ordinary skill in the art would have found it obvious to modify the method of Erharter such that a combuster, rather than an electric heater, is used to generate a heated carbon dioxide and steam stream effluent.
Erharter does not teach the temperature of the heated carbon dioxide effluent is about 550 °C to about 650 °C.
However, Min teaches that a temperature of about 676 °C, a value within1 the claimed range, is a suitable temperature for carbon dioxide heated by a cathode effluent (Fig. S1, annotated below, and Table S4).
It is therefore considered that a person having ordinary skill in the art would have found it obvious to use a temperature of about 676 °C, a value within the claimed range, as the temperature of the heated carbon dioxide effluent.
However, neither Erharter nor Min reasonably teach the first and second heated steam effluents have a temperature of about 550 °C to about 650 °C.
Specifically, Min indicates a temperature of about 353 °C is optimal for the heated steam effluent (Fig. S1, annotated below, and Table S4).
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Annotated Min Fig. S1 with Temperature Values from Table S4
Furthermore, Erharter teaches the first heated steam effluent is the second steam feed stream (see Fig. 4, annotated above). However, this sequential arrangement is inconsistent with the combined claim limitations “a first steam feed stream having a temperature of about 250 °C to about 350 °C … to generate a first heated steam effluent having a temperature of about 550 °C to about 650 °C” and “heating a second steam feed stream having a temperature of about 250 °C to about 350 °C ...”, because the claims require the first heated steam effluent and second steam feed streams to have non-overlapping temperature ranges.
Thus, Erharter in view of Min cannot reasonably render the cumulative limitations of claim 1 obvious.
Kresnyak teaches a method for recovering thermal energy during co-electrolysis of steam and carbon dioxide (abstract and Fig. 4), wherein the method comprises combusting tail gas (“tail gas 411” para. 140 and Fig. 4) in a combustor (“duct burner 530” para. 152 and Fig. 4).
However, the method of Kresnyak does not teach the heat from the combustor is used to heat the feed to the co-electrolyzer, but rather is used to heat a “biomass gasifier 410” (para. 144 and Fig. 4).
Therefore, Kresnyak cannot reasonably provide a motivation to modify the methods of Erharter or Min, alone or in combination, to read on the cumulative limitations of claim 1.
Braun teaches a method of recovering thermal energy during co-electrolysis (abstract and Fig. 1), wherein a combustor (“LFG burner 122” para. 57 and Fig. 1) is used to heat the CO2 feed (“heat-exchanger 104” Id.), the CO2 and steam feed to the cathode (“heat-exchanger 108” Id.), and purge feed to the anode (“heat-exchanger 116” Id.), and wherein the cathode effluent is used to heat first and second steam feeds to the electrolyzer (“heat exchanger 124” Id.).
However, Braun does not teach the anode effluent is used to heat the steam feed, or the cathode effluent is used to heat the carbon dioxide feed.
Therefore, Braun cannot reasonably provide a motivation to modify the methods of Erharter or Min, alone or in combination, to read on the cumulative limitations of claim 1.
Rueger teaches for recovering thermal energy from a co-electrolysis system (abstract and Fig. 1), wherein the carbon dioxide and steam feed is heated using the cathode effluent (“heat exchanger 6” para. 142 and Fig. 1). However, the steam and carbon dioxide feeds to the electrolyzer in Rueger are combined before entering the heat exchanger (see Fig. 1), and therefore Rueger cannot reasonably provide a motivation to modify the methods of Erharter or Min, alone or in combination, to read on the cumulative limitations of claim 1.
Thus, the prior art of record, taken as a whole, does not reasonably teach or render obvious the cumulative limitations of claim 1. Claim 1 is therefore patentably distinguished over the prior art of record.
Furthermore, claim 1 as currently drafted is considered to be patentably distinguished from the claims of related patent US No. 12331417 B1 and related applications 18/538372 (corresponding to US Pat. Pub. 2025/0198016) and 18/538395 (corresponding to US Pat. Pub. 2025/0197328).
Regarding US Pat. No. 12331417 B1, claim 1 of this patent recites heating a first steam feed stream in a second heat exchanger using a second cathode effluent from the cathode of the electrolyzer as a heat transfer medium to generate a first heated steam effluent having a temperature of about 550 °C to about 650 °C (lines 11-16), and
combusting, in a combustion unit, a tail gas stream to transfer heat from the combusting to the second heated steam effluent (lines 17-20).
However, claim 1 of US Pat. No. 12331417 B1 recites heating a steam feed stream using to produce the first heated feed stream having a temperature from about 350 to about 450 °C using the anode effluent (lines 2-10), which is materially distinct from the limitations of claim 1.
Therefore, claim 1 of the instant application is patentably distinguished from claim 1 of US Pat. No. 12331417 B1.
Regarding co-pending applications 18/538372 and 18/538395, the claims of these applications, as currently drafted, cover the subject matter claimed in claim 1, but are broader in scope, and it is not considered that a person having ordinary skill in the art would have a motivation to modify the inventions recited in these applications as recited in claim 1. Therefore, claim 1 of the instant application is patentably distinguished over these co-pending applications.
As claim 1 is patentably distinguished over the prior art and does not raise issues of double patenting, claim 1 is in condition for allowance.
Regarding claims 2-12, claims 2-12 depend from claim 1, and therefore incorporate the patentably distinct subject matter recited in claim 1. Claims 2-12 are therefore patentably distinguished over the prior art for at least the reasons enumerated for claim 1, above.
Regarding claim 13, the prior art of record, taken as a whole, does not reasonably teach or render obvious the cumulative limitations of claim 13, taken as a whole, for the same reasons enumerated for claim 1, above, mutatis mutandis.
Furthermore, claim 13 as currently drafted is considered to be patentably distinguished from the claims of related US Pat. No. 12331417 B1 and related applications 18/538372 (corresponding to US Pat. Pub. 2025/0198016) and 18/538395 (corresponding to US Pat. Pub. 2025/0197328), for the same reasons enumerated .
Therefore, claim 13 is patentably distinguished over the prior art of record for the same reasons enumerated for claim 1, above, mutatis mutandis. Claim 13 is therefore in condition for allowance.
Regarding claims 14-18, claims 14-18 depend from claim 13, and therefore incorporate the patentably distinct subject matter recited in claim 13. Claims 14-18 are therefore patentably distinguished over the prior art for at least the reasons enumerated for claim 13, above.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDER R PARENT whose telephone number is (571)270-0948. The examiner can normally be reached M-F 11:00 AM - 6 PM EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Luan V. Van can be reached at (571)272-8521. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ALEXANDER R. PARENT/Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795
1 “about 650 °C” covers values up to 780 °C, see para. 47 of the instant specification.
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