Prosecution Insights
Last updated: April 19, 2026
Application No. 18/299,770

Calcination Process

Non-Final OA §102§103§112
Filed
Apr 13, 2023
Examiner
BAUM, ZACHARY JOHN
Art Unit
1736
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Origen Power Ltd.
OA Round
1 (Non-Final)
79%
Grant Probability
Favorable
1-2
OA Rounds
2y 9m
To Grant
93%
With Interview

Examiner Intelligence

Grants 79% — above average
79%
Career Allow Rate
86 granted / 109 resolved
+13.9% vs TC avg
Moderate +14% lift
Without
With
+14.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
26 currently pending
Career history
135
Total Applications
across all art units

Statute-Specific Performance

§103
41.4%
+1.4% vs TC avg
§102
21.0%
-19.0% vs TC avg
§112
28.4%
-11.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 109 resolved cases

Office Action

§102 §103 §112
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 without traverse of Group I, in the reply filed on November 10 is acknowledged. Claims 25-30 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on November 10. Claim Objections Claims 2-17, 19-20, and 22-24 are objected to because of the following informalities: Dependent claims 2-17, 19-20, and 22-24 each begin, “A process according to claim”. In each instance, this phrase should be edited to read, “The process according to claim”. In line 3 of claim 18, after “recirculating”, “a” should be edited to read, “at”. Appropriate correction is required. 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 3, 7, and 20 are 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. A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 3 recites the broad recitation "a plurality of series connected cyclonic heat exchangers", and the claim also recites "preferably at least four cyclonic heat exchangers" which is the narrower statement of the range/limitation. Additionally, claims 7 and 20 each recite the broad recitation "from 500°C to 1200°C", and the claims also each recite "preferably from at least 650°C to 1200°C" which is the narrower statement of the range/limitation. The claims are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims. Notwithstanding the foregoing, any of the recited ranges/limitations will be considered to read on each respective claim, as individual claims are given their broadest reasonable interpretation in light of the specification. See MPEP § 2111. Claim Rejections - 35 USC § 102 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 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 1-8, 10-11, 14, 18-19, and 21-24 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Panier (U.S. 2017/0267582 A1). Regarding claim 1, Panier teaches a process for producing metal oxide in a calciner (Panier, Fig. 1, [0022]-[0103]), the process comprising: a. pre-heating a metal carbonate particulate stream (Panier, [0006], raw meal is CaCO3), prior to the particulate stream being fed into the calciner (Panier, [0050]); and, b. calcining the particulate stream in a calciner (Panier, [0098]) to produce a raw stream comprising metal oxide (Panier, [0006], CaO) and a flue gas comprising CO2 (Panier, [0099]) wherein at least a portion of the flue gas comprising CO2 produced in step (b) is used to pre-heat the metal carbonate particulate in step (a) (Panier, [0067]); and wherein at least a portion of the flue gas comprising CO2 produced in step (b) is recycled back into the calciner via a furnace (Panier, [0069], [0073], [0075], kiln). Panier does not explicitly teach that the calciner is a flash calciner. However, the instant Specification states the following: “The basic design requirement for the flash calciner 301 is to ensure that the upward gas velocity is sufficiently high to ensure that the finely divided solid material is held in suspension and conveyed out of the flash calciner 301 with the exiting gas flow” (Specification, Page 10, lines 14-16). Panier’s calciner operates on this same principle (Panier, [0098], where “entrained” has the same meaning as “held in suspension”). Therefore, despite not being designated as a “flash calciner”, Panier’s calciner is nonetheless a flash calciner. Regarding claim 2, Panier teaches the process according to claim 1, as discussed above, wherein step (a) is carried out by feeding the particulate stream and a portion of the flue gas stream comprising CO2 into a cyclonic heat exchanger system in a counter flow arrangement (Panier, [0067], gas evacuated from the top end of the calciner is introduced into the preheater before being introduced into calciner, which constitutes a counter-flow arrangement). Regarding claim 3, Panier teaches the process according to claim 2, as discussed above, wherein the cyclonic heat exchanger system comprises a plurality of series connected cyclonic heat exchangers (Panier, Fig. 1, [0101] preheater tower 30 comprising cyclones 31, 32, and 33). Regarding claim 4, Panier teaches the process according to claim 1, as discussed above, comprising a step of separating a portion of the raw stream, after it exits the flash calciner, into a metal oxide stream and a flue gas stream (Panier, Fig. 1, [0100]) which comprises CO2 (Panier, [0099]). Regarding claim 5, Panier teaches the process according to claim 4, as discussed above, wherein the separation of the portion of the raw stream is carried out by a cyclone separator (Panier, Fig. 1, [0100]). Regarding claims 6-7, Panier teaches the process according to claim 1, as discussed above, wherein the furnace heats the flue gas comprising CO2 to a temperature of 800°C to 900°C (claim 7) (Panier, [0102], recycled flue gas is introduced into the calciner at a temperature of at 800°C to 900°C, which implies that the flue gas has been heated to this temperature), which is a temperature capable of maintaining auto-ignition of a fuel within the flash calciner (claim 6) (Panier, [0018], equilibrium temperature of the decarbonation reaction in air is in the range of 800°C to 850°C, thereby meeting the claim requirement of auto-ignition). Regarding claim 8, Panier teaches the process according to claim 4, as discussed above, comprising a step of feeding a portion of the metal oxide Regarding claim 10, Panier teaches the process according to claim 1, as discussed above, comprising a step of feeding an admixture of fuel and oxidant into the flash calciner (Panier, [0024], [0030], [0034]). Regarding claim 11, Panier teaches the process according to claim 1, as discussed above, comprising a step of feeding an admixture of fuel and oxidant into the furnace (Panier, [0075], combustion takes place in the kiln with a kiln oxidant, implying that fuel is combined with the oxidant in a combustion reaction). Regarding claim 14, Panier teaches the process according to claim 1, as discussed above, wherein a portion of the flue gas is driven using a fan to the flash calciner (Panier, Fig. 1, [0102], extractor fan 60). Regarding claim 18, Panier teaches a process (Panier, Fig. 1, [0022]-[0103]) for calcining a metal carbonate feedstock (Panier, [0006], raw meal is CaCO3) within a calciner (Panier, Fig. 1, [0093], calciner 10) to produce a metal oxide (Panier, [0006], CaO) and flue gas comprising CO2 (Panier, [0099]), wherein the process comprises recirculating at least a portion of the CO2 flue gas within a closed loop fluid path which includes the calciner (Panier, Fig. 1, [0102], stream 80 is connected between top cyclone 33 and calciner 10). Panier does not explicitly teach that the calciner is a flash calciner. However, the instant Specification states the following: “The basic design requirement for the flash calciner 301 is to ensure that the upward gas velocity is sufficiently high to ensure that the finely divided solid material is held in suspension and conveyed out of the flash calciner 301 with the exiting gas flow” (Specification, Page 10, lines 14-16). Panier’s calciner operates on this same principle (Panier, [0098], where “entrained” has the same meaning as “held in suspension”). Therefore, despite not being designated as a “flash calciner”, Panier’s calciner is nonetheless a flash calciner. Panier does not explicitly teach that the recirculating is conducted at a pressure above atmospheric pressure. However, as the fan is blowing air at a rate sufficient to suspend the solid starting material (Panier, [0098]), the pressure of the recirculating would necessarily be above atmospheric pressure. Regarding claim 19, Panier teaches the process according to claim 18, as discussed above, wherein the CO2 flue gas is recirculated at above atmospheric pressure within the fluid path using a fan (Panier, Fig. 1, [0102], Panier, Fig. 1, [0102], stream 80 is connected between top cyclone 33 and calciner 10 and recirculated using extractor fan 60). Regarding claim 21, Panier teaches a process (Panier, Fig. 1, [0022]-[0103]) for calcining a metal carbonate feedstock (Panier, [0006], raw meal is CaCO3) within a calciner (Panier, Fig. 1, [0093], calciner 10) to produce a raw stream comprising metal oxide (Panier, [0006], CaO) and a flue gas comprising CO2 (Panier, [0099]), wherein the process comprises recirculating and feeding a portion of the flue gas comprising CO2 back into the calciner (Panier, [0067]) via a fluid path which includes a preheater furnace which heats the flue gas comprising CO2 (Panier, [0102], “If appropriate, the recycle flue gas 80 can be preheated before being reintroduced into calciner 10 (not illustrated).”) to a temperature capable of maintaining auto-ignition of a fuel within the calciner (Panier, [0102], recycled flue gas is introduced into the calciner at a temperature of at 800°C to 900°C, which implies that the flue gas has been heated to this temperature), which is a temperature capable of maintaining auto-ignition of a fuel within the flash calciner (Panier, [0018], equilibrium temperature of the decarbonation reaction in air is in the range of 800°C to 850°C, thereby meeting the claim requirement of auto-ignition). Regarding claim 22, Panier teaches the process according to claim 21, as discussed above, in which the temperature is from 800°C to 900°C (Panier, [0102]). Regarding claim 23, Panier teaches the process according to claim 21, as discussed above, wherein the CO2 flue gas is recirculated within the fluid path using a fan (Panier, Fig. 1, [0102], stream 80 is connected between top cyclone 33 and calciner 10 and recirculated using extractor fan 60). Regarding claim 24, Panier teaches the process according to claim 21, as discussed above, wherein the recirculated CO2 flue gas is used to carry a fluidized stream of metal carbonate feedstock through one or more counter flow cyclonic heating stages, such that the metal carbonate feedstock is thereby heated by the CO2 flue gas prior to being fed into the flash calciner (Panier, Fig. 1, [0101]). 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 nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 20 is rejected under 35 U.S.C. 103 as being unpatentable over Panier (U.S. 2017/0267582 A1), as applied to claim 18 above. Regarding claim 20, Panier teaches the process according to claim 18, as discussed above, wherein the CO2 flue gas is heated within a preheater furnace (Panier, [0102], “If appropriate, the recycle flue gas 80 can be preheated before being reintroduced into calciner 10 (not illustrated).”). Panier does not explicitly teach that preheating of the CO2 flue gas is done so by combustion of a fuel/oxygen mixture. However, it would nonetheless have been obvious to employ combustion of a fuel/oxygen mixture to affect preheating of the CO2 flue gas. The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art (see MPEP 2143.A.). The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, USPQ2d 1385, 1395 - 97 (2007) (see MPEP § 2143.B.). In the instant case, Panier already teaches heating by combustion of fuel and oxidant (Panier, [0061], combustion of fuel and oxidant in calciner; [0075], combustion of fuel with oxidant in kiln). Preheating the CO2 flue gas, a goal which is explicitly taught by Panier in paragraph [0102], could be done with a reasonable expectation of success by combustion of fuel and oxidant in a furnace. Claims 12-13 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Panier (U.S. 2017/0267582 A1), as applied to claim 1 above, and further in view of Bittner (U.S. 2020/0361819 A1). Regarding claim 12, Panier teaches the process according to claim 10, as discussed above, wherein the fuel comprises a fossil fuel (Panier, [0092]) and the oxidant comprises oxygen / oxygen enriched air (Panier, [0025]). Panier does not explicitly teach that the fuel is a gaseous hydrocarbon. However, Bittner teaches that gaseous hydrocarbon is a suitable calciner fuel (Bittner, [0020]). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have selected a gaseous hydrocarbon fuel as the fuel in Panier’s process. The selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. See In re Leshin, 125 USPQ 416 (CCPA 1960), Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945), and MPEP § 2144.07. In the instant case, it was known that a gaseous hydrocarbon fuel was a suitable fuel for a calciner (Bittner, [0020]). Regarding claim 13, modified Panier renders the process according to claim 12 obvious, as discussed above, wherein the oxygen enriched air comprises at least 88% by volume oxygen (Panier, [0077]). Regarding claim 17, Panier teaches the process according to claim 1, as discussed above, wherein the metal carbonate particulate stream comprises CaCO3 particles (Panier, [0006]). Panier does not explicitly teach that the CaCO3 particles have an average particle size of 5 to 120 μm. However, Bittner teaches that CaCO3 particles having a particle size of 50 μm to 5 mm, which overlaps with the claimed range of 5 to 120 μm, are suitable for a similar lime production process (Bittner, [0032]). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have selected a CaCO3 particle size of 50 μm to 5mm in Panier’s process. The selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. See In re Leshin, 125 USPQ 416 (CCPA 1960), Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945), and MPEP § 2144.07. In the instant case, it was known that a CaCO3 particle size of 50 μm to 5 mm was suitable for lime production (Bittner, [0020]). Additionally, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the particle sizes because selection of overlapping portions of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I. Claims 15-16 are rejected under 35 U.S.C. 103 as being unpatentable over Panier (U.S. 2017/0267582 A1), as applied to claim 1 above, and further in view of Jia (CN 112344742 A) (the attached machine translation is referenced below). Regarding claim 15, Panier teaches the process according to claim 1, as discussed above, wherein a portion of the flue gas stream comprising CO2 passes through a purification and storage process, wherein this step occurs after the portion of the flue gas stream is used to pre-heat the metal carbonate particulate stream (Panier, [0086]). Panier does not explicitly teach that part of this purification and storage process comprises CO2 passing through a condensing heat exchanger. However, in an analogous process of separating and storing CO2 from flue gas, Jia teaches using a condensing heat exchanger to cool CO2 in the flue gas for storage (Jia, [0062]). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have modified Panier’s method by incorporating passing CO2 through a condensing heat exchanger as taught by Jia (Jia, [0062]). The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art (see MPEP 2143.A.). The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, USPQ2d 1385, 1395 - 97 (2007) (see MPEP § 2143.B.). In the instant case, incorporating a condensing heat exchanger would yield the predictable result of preparing the CO2 in a form that can be stored after purification, which is a stated goal of Panier (Panier, [0086]). Regarding claim 16, modified Panier renders the process according to claim 15 obvious, as discussed above, comprising a step of separating and sequestering a portion of the CO2 in the flue gas stream that has passed through the condensing heat exchanger (Panier, [0086]; Jia, [0062]; see discussion of claim 15 above). Allowable Subject Matter Claims 8-9 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter: Panier (U.S. 2017/0267582 A1), Bittner (U.S. 2020/0361819 A1), Jia (CN 112344742 A, 2021) (see the attached machine translation), and Peltonen (CN 109553310 A, 2019) (the attached machine translation is referenced below) are considered to be the closest prior art to the instant claims. Regarding claim 8 and its dependent claim 9, Panier teaches the process according to claim 4, as discussed above, comprising a step of feeding the metal oxide from the separator to a rotary clinkerization kiln (Panier, [0101]), which differs from the claimed cooler. As the metal oxide (lime) product of Panier is intended to be used to form cement clinker, there would be no reason to cool the metal oxide in a cooler. It would not be obvious to stop Panier’s method before proceeding to the clinker kiln and cooling the intermediate metal oxide. Further regarding claim 8, Peltonen teaches feeding a lime produce to a cooler and using flue gas CO2 to pre-heat the calcium carbonate starting material (Peltonen, [0011], [0055]), but Peltonen’s calciner is a rotary kiln (Peltonen, [0011]) and cannot reasonably be called a “flash calciner” as required by instant claim 1 (see rejection of claim 1 under 35 U.S.C. 102(a)(1) above). As none of the cited prior art references teach or suggest feeding the metal oxide from the separator to a cooler along with each limitations of the intervening claims 1 and 4, the claim contains allowable subject matter. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to ZACHARY J. BAUM whose telephone number is (571)270-0895. The examiner can normally be reached Monday-Friday 8:30-5:00. 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, Anthony Zimmer can be reached at 571-270-3590. 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. /ZACHARY JOHN BAUM/Examiner, Art Unit 1736 /ANTHONY J ZIMMER/Supervisory Patent Examiner, Art Unit 1736
Read full office action

Prosecution Timeline

Apr 13, 2023
Application Filed
Jan 05, 2026
Non-Final Rejection — §102, §103, §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
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Grant Probability
93%
With Interview (+14.0%)
2y 9m
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