DETAILED ACTION
Response to Amendments
In response to the amendment received on 11/26/2025:
• Claims 16-28, and 31-37 are currently pending. Claims 1-15 and 29-30 are canceled. The objections to the specification are withdrawn in light of the amendments to the specification. The objections to claims 22, 23, and 25 are withdrawn in light of the amendments to the claims. The previous rejection of claim 20 under 35 U.S.C. 112(b) is maintained. The previous rejections of claims 21-22, 25, and 27 under 35 U.S.C. 112(b) are withdrawn. New 112(b) rejections over claims 16-28 and 31-37 are applied in light of the amendments to the claims.
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 Objections
Claims 25-27, 31, and 32 are objected to because of the following informalities:
• Claim 25 should be amended to read: “selected from [[a]] the group consisting of…
• Claim 26 appears to have an extra space between the term “said” and “electrolyte,” which should be removed.
• Claim 27 should be amended so that the word “partial” is replaced with the word “partially.”
• Claim 31 should be amended as follows: “…an intermediate raw meal that includes at least calcium carboxylate…”
• Applicant is advised that should claim 32 be found allowable, claim 37 will be objected to under 37 CFR 1.75 as being a substantial duplicate thereof. When two claims in an application are duplicates or else are so close in content that they both cover the same thing, despite a slight difference in wording, it is proper after allowing one claim to object to the other as being a substantial duplicate of the allowed claim. See MPEP § 608.01(m). The Examiner suggest deleting one of the duplicate claims.
Appropriate correction is required.
Claim Rejections - 35 USC § 112(a)
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 16-28 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
In claim 16, the phrase “with the use of the first carboxylic acid and/or first sulfonic acid having a pH value within a range from 3.6 to 0.7” lacks sufficient support in the specification. The specification discloses “A preferred pH-value of the electrolyte being in contract with the cathode of the electrolytic cell may be between 5 and 0.3, more preferred between 3.6 and 0.7” (see Applicant’s specification at para. 0021). Thus, Applicant’s specification provides support for the entire electrolyte at the cathode to have a pH of 3.6 to 0.7, and not specifically the first carboxylic acid and/or sulfonic acid like claimed. This is especially an issue because the claims do not limit the claimed electrolyte at the cathode to contain merely the first carboxylic acid and/or sulfonic acid, i.e., other compounds may be used in combination as electrolytes in the solution. This is best illustrated with an example. Imagine a hypothetical method that uses a first carboxylic acid, compound A, as well as an additional electrolyte, compound B, as electrolytes at the cathode. Applicant’s specification only provides support for the entire electrolyte component, i.e., compound A + compound B, to have a pH of 3.6 to 0.7; however, Applicant’s claim claims specifically the pH value to refer to only the compound A. There is no support in the specification for the compound A to have a pH range of 3.6 to 0.7 in this hypothetical case, given that the specification only provides broad support for the pH of the entire electrolyte at the cathode. Accordingly, a new matter issues arises. To correct, the Examiner suggests amending the claim to be more consistent with para. 0021 of Applicant’s specification. Claims 17-28 are also rejected by virtue of their dependency on claim 16.
Claim 26 was amended to recite “wherein the reducing includes increasing a current density at a surface of the cathode as compared to that achieved when performing said reducing with said electrolyte having the pH-value that is greater than 3.6.” This is not supported by the original disclosure. There is no discussion in the original disclosure of an electrolyte having a pH value greater than 3.6. To correct, the Examiner suggests deleting the claim.
Claim Rejections - 35 USC § 112(b)
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 16-28 and 31-37 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.
In claim 16, the phrase “with the use of the first carboxylic acid and/or first sulfonic acid having a pH value within a range from 3.6 to 0.7” is confusing. First, there is no previous mention of pH in the claims, generating confusion as to whether these acids are different from the previously claimed acids earlier in the claim (i.e., antecedent basis issues arise). Further, given the manner in which the phrase is written, it is unclear whether the pH range applies ONLY to the first sulfonic acid or BOTH the first sulfonic acid and the first carboxylic acid. Moreover, Applicant’s specification only provides support for the pH range applying to the electrolyte at the cathode as a whole (see Applicant’s specification at para. 0021), which creates confusion regarding the claim, as the claim allows for components in addition to the first carboxylic acid and first sulfonic acid to be present as electrolytes in the solution (also see the 112(a) rejection above). For the purposes of examination, the Examiner is interpreting the claimed pH range to refer to the pH value range of the entire electrolyte at the cathode in the solution, as indicated in para. 0021 of Applicant’s specification. Claims 17-28 are also rejected by virtue of their dependency on claim 16. To correct the above issues, the Examiner suggests amending the claim to be more consistent with para. 0021 of Applicant’s specification.
In claims 20-22, 25, 31, 35, and 36, the claimed phrase “second sulfonic acid” is used. However, there is no previous mention of a “second sulfonic acid” in the claims, and thus, the term lacks sufficient antecedent basis. For the purposes of examination, the Examiner is interpreting any sulfonic acid component from the electrolytic cell to read on the claimed “second sulfonic acid.” Claims 23-24 are also rejected by virtue of their dependency on claim 20. Further, claims 32-34 and 37 are also rejected by virtue of their dependency on claim 31.
In claim 26, the term “said electrolyte having the pH-value that is greater than 3.6” lacks sufficient antecedent basis in the claims. There is no previous mention of an electrolyte having a pH value greater than 3.6. For the purposes of examination, the Examiner is interpreting any hypothetical electrolyte having a pH-value of greater than 3.6., e.g., 12, to read on the claim 26 electrolyte. To correct, the Examiner suggests deleting the claim (see 112(a) rejection of claim 26 above as well).
In claim 28, the limitation “almost fully avoiding a process of carbonate formation” is unclear. The phrase “almost fully avoiding” is a relative term that renders the claim indefinite. What constitutes “almost fully avoiding?” How much formed carbonate is enough to still read on “almost fully avoiding?” The answers to these questions are unclear. For the purposes of examination, the Examiner is interpreting any process that reads on claim 16 and the rest of claim 28 to necessarily “almost fully avoid” carbonate formation. To correct, the Examiner suggests deleting the limitation “and wherein said reducing includes almost fully avoiding a process of carbonate formation” from the claim.
In claim 31, the term “the at least the portion of the first and second carboxylic acids and/or first and second sulfonic acids” lacks sufficient antecedent basis. There is no previous mention of such acids in the claim. For the purposes of examination, the Examiner is interpreting the method to be like that claimed in claim 22. Claims 32-37 are also rejected by virtue of their dependency on claim 31.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 16-18, 20, 25, and 26 are rejected under 35 U.S.C. 103 as being unpatentable over Gibbs et al. (Gibbs, Michael J, et al. “CO2 Emissions From Cement Production.” Intergovernmental Panel on Climate Change, 8 Dec. 2003, www.ipcc-nggip.iges.or.jp/public/gp/bgp/3_1_Cement_Production.pdf) (hereinafter referred to as “Gibbs”), in view of Sivasankar et al. (US-20140021059-A1) (hereinafter referred to as “Sivasankar”), or, in the alternative, further in view of Ding et al. (US-20230226486-A1) (hereinafter referred to as “Ding”) and Kramer et al. (WO-2014042781-A2), with reference to the included machine translation (hereinafter referred to as “Kramer”).
Regarding claim 16, Gibbs teaches a method configured for operating a cement clinker line (see Gibbs at pg. 1, para. 1 and pg. 2, para. 1-3, teaching a method for the formation of clinker, in which limestone (CaCO3) is converted to lime (CaO) with CO2 production as a by-product), the method comprising at least:
• converting a CaCO3 comprising raw meal into calcined raw meal and at least CO2 and/or sintering calcined raw meal in a kiln, thereby obtaining at least cement clinker and CO2 (see Gibbs at pg. 1, para. 1 and pg. 2, para. 1-3, teaching a calcination step in which calcium carbonate is heated in a rotary kiln to form calcium oxide/clinker and CO2 as a by-product).
While Gibbs teaches the method outlined above, Gibbs fails to explicitly teach the method as further comprising the steps of:
separating the CO2 from the calcined raw meal and/or the clinker; and further comprising the steps of: dissolving at least a portion of the CO2 in a first carboxylic acid and/or a first sulfonic acid to form a dissolved CO2 and/or liquifying at least a portion of the CO2 to form a liquified CO2; and reducing the dissolved and/or liquified CO2 electrolytically at a cathode of an electrolytic cell to a second carboxylic acid with the use of the first carboxylic acid and/or first sulfonic acid having a pH value within a range from 3.6 to 0.7 as an electrolyte at the cathode.
However, Sivasankar teaches a process in which CO2 is electrochemically reduced to formic acid (see Sivasankar at para. 0017-0018), resulting in reduced CO2 emissions (see Sivasankar at para. 0004-0005). Sivasankar further teaches the carbon dioxide gas to be continuously bubbled through the cathodic electrolyte solution (see Sivasankar at para. 0021), thus necessarily suggesting at least some of the CO2 to be dissolved in the solution. Moreover, Sivasankar teaches the concentration of formic acid within the cathode to be at or below 500 ppm, and further teaches an example in which the formic acid concentration continuously remains at between 8 and 15 ppm (see Sivasankar at para. 0032). Consequently, since Sivasankar teaches formic acid may be left within the cathode during the electrochemistry process, it necessarily follows the formic acid functions as an electrolyte in the cathode. In other words, one of ordinary skill could readily imagine the CO2 dissolving in the cathode electrolyte solution – a solution which contains small amounts of formic acid generated in a previous reduction step – and further can readily imagine the formic acid functioning as an electrolyte in such a solution. Thus, the process taught by Sivasankar reads on the claims, where the formic acid functions as both the first and second carboxylic acid. Products of identical chemical composition cannot have mutually exclusive properties. See MPEP § 2112.01(II).
Furthermore, Sivasankar teaches the carbon dioxide used in their process may be sourced from cement factories (see Sivasankar at para. 0030).
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to separate the CO2 from the method of Gibbs, and electrochemically reduce the CO2 into a formic acid product via the method taught by Sivasankar. One of ordinary skill in the art would have been motivated to do so in order to reduce carbon emissions (see Sivasankar at para. 0004-0005).
Following the above modification, the method of modified Gibbs includes a step of dissolving CO2 in an electrolyte solution containing small amounts of formic acid leftover from a previous reduction step, whereby the CO2 is subsequently reduced into formic acid. The small trace of formic acid leftover necessarily functions as an electrolyte in the solution.
While modified Gibbs teaches the method outlined above, modified Gibbs fails to explicitly teach the pH of the electrolyte at the cathode to range from 3.6 to 0.7 (see the interpretation set forth in the 112(b) rejection above).
However, Sivasankar teaches their catholyte to have a pH of approximately 4 to 7 (see Sivasankar at para. 0025 and 0026; note that the compartment 114b taught by Sivasankar is the cathode). While Sivasankar does not define the term “approximately,” the term is known in the art to refer to a variation of +/- 10% (see Ding at para. 0026). After applying a +/- 10% variation to the pH range of “approximately 4 to 7,” the range converts to a range of 3.6 to 7.7 (4 • 0.9 = 3.6; 7 • 1.1 = 7.7).
Further, catholytes in similar methods where CO2 is reduced to formic acid are known in the art to have pH values as low as 3 (see Kramer at para. 0008 and 0054).
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to use a pH range of 3.6 to 7.7 for the catholyte in Sivasankar (i.e., in modified Gibbs), given that “approximately” is known to refer to a variation of +/- 10% in the art and further that pH values as low as 3 may be used in similar methods in the art (see Kramer at para. 0008 and 0054 and Ding at para. 0026). This range of 3.6 to 7.7 touches an end-point of the claimed range, establishing a prima facie case of obviousness, see MPEP § 2144.05.
Even if the term “approximately” refers to a variation of less than +/- 10%, it is the Examiner’s position that the range of “approximately 4 to 7” taught by Sivasankar and the claimed range of “3.6 to 0.7” are close at their end-points. A prima facie case of obviousness exists where the claimed ranges and prior art ranges do not overlap but are close enough that one skilled in the art would have expected them to have the same properties. See Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 227 USPQ 773. See MPEP § 2144.05(I). Applicants have provided no data evidencing the range of 3.6 to 0.7 to demonstrate unexpected results (see “Response to Arguments” section below). Further, pH values that overlap the claimed range are known to be used in similar methods in the art (see Kramer at para. 0008 and 0054). Accordingly, the range of “approximately 4 to 7” and “3.6 to 0.7” are sufficiently close to establish a prima facie case of obviousness. See MPEP § 2144.05(I).
Regarding claims 17 and 25, modified Gibbs teaches the formation of formic acid, i.e., methanoic acid, as a reduction product (corresponds to the claimed “second carboxylic acid”) (see Sivasankar at para. 0017-0018).
Regarding claim 18, modified Gibbs teaches Indium may suitably be used as a cathode (see Sivasankar at para. 0019).
Regarding claim 20, modified Gibbs teaches the formic acid as being extracted via a product extractor (see Sivasankar at para. 0031).
Regarding claim 26, the formic acid leftover in the electrolytic solution is the same as the formic acid produced in the reduction process (see claim 16 analysis above). Furthermore, it necessarily follows that since the formic acid of modified Gibbs is the same acid as that claimed, and further since the pH of the acid is < 7, the current density is increased relative to an electrolyte with a pH above 3.6, e.g., a pH of 12 (also see Applicant’s specification at para. 0018). In other words, formic acid as an electrolyte necessarily increases the current density compared to an electrolyte with a pH of 12 by virtue of the acidic nature of the compound. Products of identical chemical composition cannot have mutually exclusive properties. See MPEP § 2112.01(II).
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Gibbs in view of Sivasankar, or alternatively further in view of Ding and Kaczur, as applied to claim 16 above, and further in view of Goetheer et al. (US-20210031137-A1) (hereinafter referred to as “Goetheer”).
Regarding claim 19, while modified Gibbs teaches the method according to claim 16 outlined above, modified Gibbs fails to explicitly teach the electrolyte as being heated at least θ °C above ambient temperature, wherein θ E {2, 5, 10, 15, 20, 25, 30, 40, 50, 60, 70}.
However, Goetheer teaches a method of electrochemically reducing CO2 into a reaction product, such as formic acid (see Goetheer at para. 0030-0034 and 0071). Goetheer further teaches the catholyte may include an organic acid (see Goetheer at para. 0062). Moreover, Goetheer teaches the catholyte may be operated at a temperature of between -10 and 95 °C, and that temperatures below 0 °C increase the operating costs while temperatures above 70 °C adversely affect solubility of the carbon dioxide and semi-permeable separator integrity/selectivity in the electrochemical cell (see Goetheer at para. 0065).
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to set the temperature of the catholyte in the method of modified Gibbs to range from 0 to 70 °C. One of ordinary skill in the art would have been motivated to do so in order to reduce operating costs, and to prevent the solubility of carbon dioxide and the semi-permeable separator integrity/selectivity from being adversely affected (see Goetheer at para. 0065).
This range of 0 to 70 °C overlaps the claimed range, establishing a prima facie case of obviousness, see MPEP § 2144.05.
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Gibbs in view of Sivasankar, or alternatively further in view of Ding and Kaczur, as applied to claim 16 above, and further in view of Doyle (Doyle, Amanda. “Producing Cement Using Electrolysis.” The Chemical Engineer, 29 Oct. 2019, www.thechemicalengineer.com/news/producing-cement-using-electrolysis/) (hereinafter referred to as “Doyle”) and Carrasco-Maldonado et al. (Carrasco-Maldonado, Francisco, et al. “Oxy-fuel combustion technology for cement production – State of the Art Research and Technology Development.” International Journal of Greenhouse Gas Control, vol. 45, Feb. 2016, pp. 189–199, https://doi.org/10.1016/j.ijggc.2015.12.014) (hereinafter referred to as “Carrasco-Maldonado”).
Regarding claim 27, while modified Gibbs teaches the method according to claim 16 outlined above, modified Gibbs fails to explicitly teach the method as further comprising withdrawing O2 from an anode of the electrolytic cell and providing the O2 to a burner of the kiln and/or using the O2 as to at least partial replace hot air provided to the kiln and/or hot air provided to a calciner.
However, it is well-known that oxygen may be used in a kiln for a combustion process as so-called “oxyfuel”, leading to a more efficient and cheaper method of carbon capture and storage (see Carrasco-Maldonado at pg. 190, left column, last paragraph; and pg. 190, right column, para. 1-2). Furthermore, it is known that oxygen generated from the electrochemical reduction of CO2 may be used as oxy-fuel in a kiln (see Doyle at pg. 2, para. 2), and one of ordinary skill would readily recognize the sustainable benefits of recycling the generated oxygen back into the method.
Sivasankar teaches their electrochemical reduction process as generating oxygen as a by-product (see Sivasankar at para. 0034).
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to use an oxyfuel process in the kiln of modified Gibbs, and to further feed the oxygen generated as a by-product of the reduction process into the kiln. One of ordinary skill in the art would have been motivated to do so in order to apply a more efficient and cheaper method of carbon capture and storage, and to further obtain sustainable benefits related to recycling the generated oxygen (see Carrasco-Maldonado at pg. 190, left column, last paragraph; and pg. 190, right column, para. 1-2; also see Doyle at pg. 2, para. 2).
Claims 16-21, 25, 26, and 28 are rejected under 35 U.S.C. 103 as being unpatentable over Gibbs in view of Goetheer, Kaczur (US-20160017503-A1) (hereinafter referred to as “Kaczur”) and Kramer.
Regarding claim 16, Gibbs teaches a method configured for operating a cement clinker line (see Gibbs at pg. 1, para. 1 and pg. 2, para. 1-3, teaching a method for the formation of clinker, in which limestone (CaCO3) is converted to lime (CaO) with CO2 production as a by-product), the method comprising at least:
• converting a CaCO3 comprising raw meal into calcined raw meal and at least CO2 and/or sintering calcined raw meal in a kiln, thereby obtaining at least cement clinker and CO2; (see Gibbs at pg. 1, para. 1 and pg. 2, para. 1-3, teaching a calcination step in which calcium carbonate is heated in a rotary kiln to form calcium oxide/clinker and CO2 as a by-product);
While Gibbs teaches the method outlined above, Gibbs fails to explicitly teach the method as further comprising the steps of:
separating the CO2 from the calcined raw meal and/or the clinker; and further comprising the steps of: dissolving at least a portion of the CO2 to form a dissolved CO2; and/or liquifying at least a portion of the CO2 to form a liquified CO2; and reducing the dissolved and/or liquified CO2 electrolytically at a cathode of an electrolytic cell to a second carboxylic acid, and
wherein the CO2 is dissolved in a first carboxylic acid and/or a first sulfonic acid wherein the first carboxylic acid and/or first sulfonic acid is used as an electrolyte, and
wherein the pH value of the electrolyte at the cathode ranges from 3.6 to 0.7 (see the interpretation set forth in the 112(b) rejection above).
Regarding (1.), Goetheer teaches a method for electrochemically reducing carbon
dioxide, comprising:
a) contacting a carbon dioxide-containing gas stream with a capture solvent, thereby absorbing carbon dioxide from the carbon dioxide-containing gas stream to form a carbon dioxide-rich capture solvent;
b) introducing at least part of the carbon dioxide-rich capture solvent into a cathode compartment of an electrochemical cell;
c) applying an electrical potential between an anode and a cathode in the electrochemical cell sufficient for the cathode to reduce carbon dioxide into a reduced carbon dioxide product or product mixture in the carbon dioxide-rich capture solvent, thereby providing a carbon dioxide-poor capture solvent; and
d) collecting the reduced carbon dioxide product or product mixture (see Goetheer at para. 0030-0034).
Goetheer further teaches the reduced carbon dioxide product may include carboxylic acids, such as formic acid (see Goetheer at para. 0071). Consequently, it necessarily follows that Goetheer teaches a method in which the carbon dioxide brought into contact with the capture solvent “dissolves” in the solvent and is subsequently electrochemically reduced into a carboxylic acid product, such as formic acid. Moreover, Goetheer teaches their method as helping to reduce carbon emissions and as being less expensive and more energy and resource efficient (see Goetheer at para. 0022-0025).
Additionally, Goetheer teaches the carbon dioxide source may be industrial waste gasses from cement factories containing high amounts of carbon dioxide (see Goetheer at para. 0044).
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to separate the CO2 from the method of Gibbs, and electrochemically reduce the CO2 into a carboxylic acid product via the method taught by Goetheer. One of ordinary skill in the art would have been motivated to do so in order to reduce carbon emissions and to employ a less expensive and more energy and resource efficient method of doing so (see Goetheer at para. 0022-0025).
Regarding (2.), Kaczur teaches a method of electrochemically reducing carbon dioxide into a reaction product, such as formic acid (see Kaczur at para. 0035 and 0107). Kaczur further teaches the catholyte (i.e., the electrolyte for the cathode) may include non-aqueous electrolytes, such as methanesulfonic acid (see Kaczur at para. 0251).
Goetheer teaches the cathode may contain a catholyte, and that the catholyte may be an organic acid (see Goetheer at para. 0052 and 0062).
In this case, methanesulfonic acid is a known material suitable for use as a catholyte in an electrochemical CO2 reduction process (as exemplified by Kaczur at para. 0251), and thus its use as an organic acid catholyte in the method taught by modified Gibbs would yield a reasonable expectation of success.
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to use methanesulfonic acid as the catholyte in the method of modified Gibbs, as 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. Combining known elements to obtain predictable results is within the level of ordinary skill in the art. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). See MPEP § 2143.
Regarding (3.), Kaczur further teaches the pH of their catholyte may range from 3 to 12, and that the pH may be a function of the catalysts used, such that there may be no corrosion at the electrochemical cell and catholyte operating conditions (see Kaczur at para. 0192). Furthermore, an identical pH range of 3 to 12 for identical reasons is known in the art for catholytes, such as methanesulfonic acid, when reducing CO2 to formic acid (see Kramer at para. 0008, 0051, and 0054).
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to set the pH of the catholyte of modified Gibbs, e.g., methanesulfonic acid, to range from 3 to 12. One of ordinary skill in the art would have been motivated to do so such that there may be no corrosion at the electrochemical cell and catholyte operating conditions (see Kaczur at para. 0192 and Kramer at para. 0054).
The range of 3 to 12 overlaps the claimed range, establishing a prima facie case of obviousness, see MPEP § 2144.05.
Following the above modification, it necessarily follows that at least a portion of the carbon dioxide dissolves into the methanesulfonic acid catholyte following contact of the carbon dioxide with the fluid, thus resulting in the claimed limitations to be met.
Regarding claims 17 and 25, modified Gibbs teaches the formation of formic acid, i.e., methanoic acid, as a reduction product (corresponds to the claimed “second carboxylic acid”) (see Goetheer at para. 0071).
Regarding claim 18, modified Gibbs teaches Indium may suitably be used as a cathode (see Goetheer at para. 0055).
Regarding claim 19, modified Gibbs teaches the catholyte may be operated at a temperature ranging from 5 to 60 °C (see Goetheer at para. 0065), which overlaps the claimed range, establishing a prima facie case of obviousness, see MPEP § 2144.05.
Regarding claim 20, modified Gibbs teaches the reduced carbon dioxide product as being separated using a separator, leaving a carbon dioxide-poor capture solvent (see Goetheer at para. 0086); thus, the carboxylic acid reduction product is “withdrawn”; also, modified Gibbs teaches the carbon dioxide-poor capture solvent may be recirculated back to the absorber unit and contacted with a carbon dioxide gas stream, thus teaching the solvent, i.e., methanesulfonic acid, may be “withdrawn” and then circulated back to the starting absorber unit (see Goetheer at para. 0086)).
Regarding claim 21, modified Gibbs teaches the carbon dioxide-poor capture solvent, i.e., methanesulfonic acid, may be recirculated back to the absorber unit and contacted with a carbon dioxide gas stream (see Goetheer at para. 0074 and Fig. 1; also see claim 20 analysis above).
Regarding claim 26, it necessarily follows that since the methanesulfonic acid of modified Gibbs is the same acid as that claimed, and further since the pH of the acid is < 7, the current density is increased relative to an electrolyte with a pH above 3.6, e.g., a pH of 12 (also see Applicant’s specification at para. 0018). In other words, methanesulfonic acid as an electrolyte necessarily increases the current density compared to an electrolyte with a pH of 12 by virtue of the acidic nature of the compound. Products of identical chemical composition cannot have mutually exclusive properties. See MPEP § 2112.01(II).
Regarding claim 28, since the organic acid catholyte may be used alone (see Goetheer at para. 0062, teaching an organic acid may be used as a catholyte in the case that a catholyte other than the capture solvent is selected; thus, Goetheer necessarily suggests the catholyte may include the organic acid alone, rather than both the organic acid and the capture solvent), it necessarily follows that the alkali metal salt concentration is 0, as methanesulfonic acid contains no alkali metal ions. Further, the acid of modified Goetheer, methanesulfonic acid, is the same as that claimed. Moreover, the pH range of modified Goetheer overlaps the claimed range (see claim 16 analysis above). Additionally, Applicant’s specification teaches that the carbonate formation process may be at least almost fully avoided “if H3O+ is the proton source for CO2-reduction [and] no or almost no OH- is generated.” Consequently, since modified Goetheer teaches the same method with the same electrolyte with the same pH as that claimed, as well as a catholyte that may include the organic acid alone, modified Goetheer necessarily teaches a reduction process which almost fully avoids a process of carbonate formation. Products of identical chemical composition cannot have mutually exclusive properties. See MPEP § 2112.01(II) (also see the interpretation set forth in the 112(b) rejection of claim 28 above).
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Gibbs in view of Goetheer, Kaczur, and Kramer, as applied to claim 16 above, and further in view of Doyle and Carrasco-Maldonado.
Regarding claim 27, while modified Gibbs teaches the method according to claim 16 outlined above, modified Gibbs fails to explicitly teach the method as further comprising withdrawing O2 from an anode of the electrolytic cell and providing the O2 to a burner of the kiln and/or using the O2 as to at least partial replace hot air provided to the kiln and/or hot air provided to a calciner.
However, it is well-known that oxygen may be used in a kiln for a combustion process as so-called “oxyfuel”, leading to a more efficient and cheaper method of carbon capture and storage (see Carrasco-Maldonado at pg. 190, left column, last paragraph; and pg. 190, right column, para. 1-2). Furthermore, it is known that oxygen generated from the electrochemical reduction of CO2 may be used as oxy-fuel in a kiln (see Doyle at pg. 2, para. 2), and one of ordinary skill would readily recognize the sustainable benefits of recycling the generated oxygen back into the method.
Geotheer teaches their electrochemical reduction process as generating oxygen at the anode (see Goetheer at para. 0092).
Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to use an oxyfuel process in the kiln of modified Gibbs, and to further feed the oxygen generated at the anode into the kiln in such a process. One of ordinary skill in the art would have been motivated to do so in order to apply a more efficient and cheaper method of carbon capture and storage, and to further obtain sustainable benefits related to recycling the generated oxygen (see Carrasco-Maldonado at pg. 190, left column, last paragraph; and pg. 190, right column, para. 1-2; also see Doyle at pg. 2, para. 2).
Response to Arguments
Applicant's arguments filed 11/26/2025 have been fully considered but they are not persuasive for at least the reasons set forth below.
First, Applicants argue their amendments overcome the previous 112(b) rejections. However, the Examiner only partially agrees. The Examiner agrees that the amendments overcome the previous 112(b) rejections over claims 21-22, 25, and 27; however, the Examiner disagrees that the amendments overcome the previous 112(b) rejection over claim 20. Accordingly, the rejection over claim 20 is maintained. Further, new 112(b) rejections over claims 16-28 and 31-37 are applied in light of the amendments to the claims, see the 112(b) rejections above.
Next, Applicants argue their invention as providing unexpected results (see Applicant’s Remarks at pg. 9-10). However, this is not found to be persuasive and so the Examiner must respectfully disagree for the following reasons:
A showing of unexpected results must be based on evidence, not argument
or speculation. In re Mayne, 104 F.3d 1339, 1343-44, 41 USPQ2d 1451, 1455-56 (Fed. Cir. 1997).
See MPEP § 2145. Applicants merely point to the conclusory statements at para. 0004, 0013, and 0018-0021 of their specification to demonstrate unexpected results; however, no data or evidence is provided to support these statements. In fact, no data or evidence is provided in the specification at all. A mere conclusion that Applicants invention demonstrates unexpected results, without data to support it, is not enough to show non-obviousness. See MPEP § 716.02.
Allowable Subject Matter
Claims 22-24 and 31-37 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112 set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
The following is an examiner's statement of reasons for allowance:
With respect to claim 22, the prior art does not reasonably teach or suggest a method configured for operating a cement clinker line, the method comprising at least: converting a CaCO3 comprising raw meal into calcined raw meal and at least CO2 and/or sintering calcined raw meal in a kiln, thereby obtaining at least cement clinker and CO2; separating the CO2 from the calcined raw meal and/or the clinker; and characterized in that it further comprises the steps of: dissolving at least a portion of the CO2 in a first carboxylic acid and/or a first sulfonic acid and/or liquifying at least a portion of the CO2; and reducing the dissolved and/or liquified CO2, respectively, electrolytically at a cathode of an electrolytic cell to a second carboxylic acid, wherein the first carboxylic acid and/or first sulfonic acid is used as an electrolyte, further comprising withdrawing at least a portion of the first and second carboxylic acids and/or first and second sulfonic acids from the electrolytic cell, wherein the converting includes reacting at least a fraction of the at least the portion of the first and second carboxylic acids and/or first and second sulfonic acids with CaCO3 comprised in the raw meal, thereby converting at least a portion of the raw meal into an intermediate raw meal comprising at least calcium carboxylate and/or calcium sulfonate, respectively.
The closest prior art includes Gibbs (Gibbs, Michael J, et al. “CO2 Emissions From Cement Production.” Intergovernmental Panel on Climate Change, 8 Dec. 2003, www.ipcc-nggip.iges.or.jp/public/gp/bgp/3_1_Cement_Production.pdf), Sivasankar (US-20140021059-A1), Ding (US-20230226486-A1), and Kramer (WO-2014042781-A2).
While Gibbs in view of Sivasankar (and alternatively Ding and Kramer) teaches most of the claimed limitations, as outlined above, modified Gibbs fails to explicitly teach reacting a fraction of the at least the portion of the first and second carboxylic acids and/or first and second sulfonic acids with CaCO3 comprised in the raw meal, thereby converting at least a portion of the raw meal into an intermediate raw meal comprising at least calcium carboxylate and/or calcium sulfonate, respectively. Sivasankar teaches the produced formic acid may be fed to bacteria to convert it into a secondary product (see Sivasankar at para. 0031); however, Sivasankar does not suggest reacting the formic acid with calcium carbonate. Further, there is no reasonable expectation of success of utilizing the formic acid formed in the specific process taught by Sivasankar in a reaction step with calcium carbonate. The prior art does not remedy this deficiency. Accordingly, claim 22 would be allowable over Gibbs in view of Sivasankar, if re-written to be in independent form and if all relevant 112 rejections are overcome.
The second closest prior art includes Gibbs (Gibbs, Michael J, et al. “CO2 Emissions From Cement Production.” Intergovernmental Panel on Climate Change, 8 Dec. 2003, www.ipcc-nggip.iges.or.jp/public/gp/bgp/3_1_Cement_Production.pdf) in view of Goetheer (US-20210031137-A1), Kaczur (US-20160017503-A1), and Kramer (WO-2014042781-A2).
While Gibbs in view of Goetheer and Kaczur teaches most of the claimed limitations, as outlined above, modified Gibbs fails to explicitly teach reacting a fraction of the at least the portion of the first and second carboxylic acids and/or first and second sulfonic acids with CaCO3 comprised in the raw meal, thereby converting at least a portion of the raw meal into an intermediate raw meal comprising at least calcium carboxylate and/or calcium sulfonate, respectively. There is no teaching or suggestion either in Goetheer or Kaczur to react the reduced product with calcium carbonate. Further, the prior art does not provide a reasonable expectation of success in doing so, particularly considering the combination of limitations as presented. Accordingly, claim 22 would be allowable over Gibbs in view of Goetheer and Kaczur, if re-written to be in independent form and if all relevant 112 rejections are overcome.
With respect to claims 23-24 and claims 31-37, the prior art fails to remedy the deficiencies for the same reasons as given above. Consequently, such claims would be allowable if re-written to be in independent form (claims 22-24) and if all relevant 112 rejections are overcome (claims 22-24 and 31-37).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jeffrey E Barzach whose telephone number is (571)272-8735. The examiner can normally be reached Monday - Friday; 8 am - 5 pm.
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/J.E.B./
Examiner, Art Unit 1731
/AMBER R ORLANDO/Supervisory Patent Examiner, Art Unit 1731