DETAILED ACTION
Election/Restrictions
Applicant's election with traverse of Group 1 claims 35-49 in the reply filed on 1/12/26 is acknowledged. The traversal is on the ground(s) that “the International Preliminary Examining Authority deemed the present claims to possess unity as set forth in International Preliminary Report on Patentability, Chapter II. No unity of invention objection was made in the International Preliminary Examination Report (IPER) completed March 29, 2022.” This is not found persuasive because the common technical feature, namely sorbing CO2 for energy storage, is already taught by Sakellariou and therefore does not provide a unifying inventive feature across the claimed groups. Because the common feature is known, it cannot provide unity among the method, composition, and system groups.
The requirement is still deemed proper and is therefore made FINAL.
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 45 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 45 recites the limitation “the particle” in lines 2-4 of the claim. There is insufficient antecedent basis for this limitation in the claim.
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.
Claims 35-49 iare rejected under 35 U.S.C. 103 as being unpatentable over Melsert US Patent 10,464,815.
Regarding claim 35, Melsert teaches a method of storing energy comprising:
a) Heating a material comprising a CO2 sorbed product (CaCO3) and an additive (mayenite, 12CaO·7Al2O3) (column 6 lines 23-25 and lines 60-63, column 10 lines 11-14, and column 18 lines 28-29) which desorbs CO2 from the material to convert the CO2 sorbed product (CaCO3) into a CO2 sorbent (CaO)(see scheme 1 in column 6 line 63 where CaCO3 + 180 KJ ⇌ CaO + CO2);
b) Wherein the additive (mayenite, 12CaO·7Al2O3) increases the long-term stability of the CO2 sorbent (CaO) by reducing occurrences of sintering and agglomerates (column 7 lines 51-59).
Melsert does not explicitly teach that the additive prevents the formation of a crust on the material, the crust minimizing or preventing the CO2 sorbent and CO₂ from reacting with one another to form the CO₂ sorbed product in a subsequent CO2 absorption step.
However, Melsert does teach incorporating calcium aluminate (mayenite) as a reinforcing structure to improve the long-term stability of CaO sorbents by reducing sintering and agglomeration during high-temperature cycling. Melsert further teaches that the additive is a calcium aluminate which similar to the claimed invention and is introduced for the same purposes of improving stability and cycle longevity of the sorbent (column 7 lines 50-60). Since agglomeration and sintering in CaO looping systems reduce pore accessibility and promote diffusion barriers (i.e. crust formation), one of ordinary skill in the art would have reasonably expected that the reinforcing calcium aluminate additive of Melsert would also mitigate crust formation during cyclic carbonation and calcination.
Regarding claim 36, the CO2 sorbent is CaO and the CO2 sorbed product is CaCO3 (column 6 line 23, line 64, and column 10 lines 11-14).
Regarding claims 37 and 38, the desorption temperature can be 950 ⁰C thus at least a temperature of 900 ⁰C and less than 1200 ⁰C (column 10 line 1).
Regarding claims 39 and 40, the additive comprises mayenite (12CaO·7Al2O3), which is a calcium aluminate phase formed from CaO and Al2O3. Thus, it would have been obvious to one having ordinary skill in the art to incorporate mayenite into the sorbent by reacting alumina with the sorbent (CaO) to form the additive (column 6 line 23-25 and column 7 lines 55-59).
Regarding claims 41 and 42, the additive comprises mayenite which is 12CaO·7Al2O3, thus is a metal oxide comprising calcium aluminate (column 7 line 59).
Regarding claim 43, Melsert teaches mayenite and is known as Ca12Al14O33, which is a calcium aluminate phase within the CaO-Al2O3 phase system. Although Melsert does not explicitly disclose Ca5Al6O14 or Ca9Al6O18, these are also calcium aluminate phases within the same CaO-Al-2-O3 phase system and are predictable stochiometric variants providing a similar structural stabilization of CaO sorbents. Thus, one having ordinary skill in the art would have expected these Ca5Al6O14 or Ca9Al6O18 calcium aluminate phases to function similarly to mayenite for improving sorbent stability.
Regarding claim 44, Melsert teaches the ratio of additive (mayenite) to the CO2 sorbed product (CaCO3) is about 20 wt% to 80 wt% based on the total weight of CaO and mayenite (column 8 lines 23-25). While Melsert does not explicitly teach the ratio of additive (mayenite) to the CO2 sorbed product (CaCO3), one having ordinary skill in the art would expect that the ratio between the additive and the CO2 sorbed product (CaCO3) would be similar to the ratio of the additive to the CO2 sorbent (CaO) because CaO and CaCO3 are merely the desorbed and sorbed forms of the same active material and are converted on a 1:1 molar basis during cycling (see scheme 1 in column 6 line 64).
Regarding claim 45, Melsert does not explicitly teach that during CO2 absorption, the additive allows the CO2 sorbent to migrate through the particle from an inner region of the particle to a surface of the particle to react with CO2 present at the surface of the particle to form the CO2 sorbed product. However, because Melsert teaches mayenite as a reinforcing structure that improves pore accessibility and cycling stability by reducing sintering and agglomeration (column 7 lines 51-59), one of ordinary skill in the art would have expected the CaO sorbent to remain accessible throughout the particle and able to react to CO2.
Regarding claim 46, Melsert teaches via scheme 1 (column 6 lines 58-64) that when CO2 is adsorbed onto the CO2 sorbent (CaO) it will release energy (as 180 KJ).
Regarding claim 47, Melsert teaches that reducing CO2 pressure affects the rate of carbonation of the CaO sorbent (column 13 lines 35-41). Because carbonation and calcination are opposing directions of the same reversible reaction (scheme 1 column 6 line 64) and are both controlled by CO2 partial pressure, one having ordinary skill in the art would have recognized that by reducing CO2 pressure would promote desorption of CO2 from CaCO3 relative to the pressure used during absorption.
Regarding claim 48, the CO2 provided can be a gas (column 6 line 10) or supercritical fluid (column 13 line 44).
Regarding claim 49, the sorbent power cycle includes atmospheric pressure (column 9 line 26), thus overlaps the range of ‘up to about 60 bar’.
Conclusion
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/SHARON PREGLER/Primary Examiner, Art Unit 1772
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