Detailed Action
This is a Final Office action based on application 18/359,672 filed on 26 July 2023. The application is a 111(a) and does not claim priority to any earlier application.
Claims 1-23 and 55-57 are pending and have been fully considered.
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 .
Status of the Rejection
The rejections of record are maintained.
Claim Rejections - 35 USC § 102
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 1-4, 7, 12-15, and 19-20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by US 2019/0099711 A1 to Hatton et al (hereinafter “Hatton”).
Regarding claim 1, Hatton teaches an electrochemical system (figure 1 system 100; para [0005]), comprising:
a salt comprising a first Lewis acid cation (para [0034], “solution contained in the system comprises ... electrolyte”; para [0062], “electrolyte is a salt ... for example, an alkali metal salt or an alkaline metal salt... examples of cations include K+, Li+, Mg+2, Ca+2, ...”; note, per instant specification pg 23 and 38, K+, Li+, Mg2+, and Ca2+ are all exemplary Lewis acid cations);
a carbamic acid compound (figure 3; para [0034], “solution contained in the system comprises a complexation agent ... In a non-limiting example, the complexation agent is ethylenediamine ... CO2 308 from incoming feed gas comprising CO2 is absorbed by ethylenediamine generating carbamate 310”); and
an electrochemical cell comprising an electrode (figure 1; para [0026], “System 100 may be an electrochemical cell. As illustrated in FIG. 1, system 100 comprises anode 102 ... and cathode 106”), wherein, upon discharge or charge of the electrochemical cell, the electrode is configured to produce a second Lewis acid cation that interacts with the carbamic acid compound to release CO2 from the carbamic acid compound (para [0034], “As the solution flows from the cathode in fluid communication with the anode (as described above) applied electrical potential 304b (e.g., continuously applied electrical potential) may oxidize Cu metal electrode 306b to Cu(II) ions 318. Upon oxidation of the Cu metal 306b (e.g., Cu metal electrode) to Cu(II) ions 318, Cu(II) may preferentially bind to ethylenediamine 310 to generate Cu(II)-ethylenediamine complex 302, thereby resulting the release of CO2 320 from carbamate 310”), and wherein the second Lewis acid cation is a stronger Lewis acid than the first Lewis acid cation (the second Lewis acid cation, Cu2+, is a stronger Lewis acid than the first Lewis acid cation (e.g. K+ or Li+) as evidenced by the fact that the Cu2+ displaced CO2 from the carbamic acid adduct and the first Lewis acid cation did not).
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Whlie Hatton describes their carbamic acid compound by the word “carbamate”, it should be noted that the specific “carbamate” disclosed by the reference is this molecule, drawn in Hatton at figure 3:
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... which is clearly a tautomeric form of (2-aminoethyl) carbamic acid:
... which is a carbamic acid compound, as claimed.
Regarding claim 2, Hatton teaches the electrochemical system of claim 1, wherein the electrode is a negative electrode (note, Hatton teaches the electrode that releases the Cu2+ Lewis acid cation is metallic Cu and it is the anode (para [0032]-[0035]), however, the instant specification at pg 11 says that either the anode or the cathode can read on the claimed negative electrode (instant pg 11), and that even a metal electrode that oxidizes to produce a metal cation is within the scope of “negative electrode” with respect to the invention (bottom of pg 36 to top of pg 37, and pg 44, in instant specification)), and the electrochemical cell further comprises a positive electrode (figure 1-2, counter electrode 106).
Regarding claim 3, Hatton teaches the electrochemical system of claim 1 and further teaches the salt is an electrolyte salt (para [0062], “the electrolyte is a salt”).
Regarding claim 4, Hatton teaches an electrochemical system (figure 1 system 100; para [0005]), comprising: a fluid source (para [0034], “solution contained in the system”) comprising:
an electrolyte salt comprising a first Lewis acid cation (para [0034], “solution contained in the system comprises ... electrolyte”; para [0062], “electrolyte is a salt ... for example, an alkali metal salt or an alkaline metal salt... examples of cations include K+, Li+, Mg+2, Ca+2, ...”; note, per instant specification pg 23 and 38, K+, Li+, Mg2+, and Ca2+ are all exemplary Lewis acid cations);
a carbamic acid compound (figure 3, carbamic acid compound 310; para [0034], “solution contained in the system comprises a complexation agent ... In a non-limiting example, the complexation agent is ethylenediamine ... CO2 308 from incoming feed gas comprising CO2 is absorbed by ethylenediamine generating carbamate 310”); and
an electrochemical cell comprising a positive electrode and a negative electrode (figure 1; para [0026], “System 100 may be an electrochemical cell. As illustrated in FIG. 1, system 100 comprises anode 102 ... and cathode 106”), wherein, upon discharge or charge of the electrochemical cell, the negative electrode is configured to produce a second Lewis acid cation (para [0034], “As the solution flows from the cathode in fluid communication with the anode (as described above) applied electrical potential 304b (e.g., continuously applied electrical potential) may oxidize Cu metal electrode 306b to Cu(II) ions 318”; note, Hatton teaches the electrode that releases the Cu2+ Lewis acid cation is metallic Cu and it is the anode (para [0032]-[0035]), however, the instant specification at pg 11 says that either the anode or the cathode can read on the claimed negative electrode (instant pg 11), and that even a metal electrode that oxidizes to produce a metal cation is within the scope of “negative electrode” with respect to the invention (bottom of pg 36 to top of pg 37, and pg 44, in instant specification)) that interacts with the carbamic acid compound to release CO2 from the carbamic acid compound (para [0034], “Upon oxidation of the Cu metal 306b (e.g., Cu metal electrode) to Cu(II) ions 318, Cu(II) may preferentially bind to ethylenediamine 310 to generate Cu(II)-ethylenediamine complex 302, thereby resulting the release of CO2 320 from carbamate 310”), and wherein the second Lewis acid cation is a stronger Lewis acid than the first Lewis acid cation (the second Lewis acid cation, Cu2+, is a stronger Lewis acid than the first Lewis acid cation (e.g. K+, Li+, Mg2+, or Ca2+) as evidenced by the fact that the Cu2+ displaced CO2 from the carbamic acid adduct and the first Lewis acid cation did not).
Regarding claim 7, Hatton teaches the electrochemical system of claim 2 wherein the negative electrode comprises a metal (para [0033], “(e.g., Cu metal)”).
Regarding claim 12, Hatton teaches the system of claim 3 and further teaches the electrolyte salt comprises a potassium (K)-containing salt, a lithium (Li)-containing salt, and/or combinations thereof (para [0062], “electrolyte is a salt ... for example, an alkali metal salt or an alkaline metal salt... examples of cations include K+, Li+, ...”).
Regarding claim 13, Hatton teaches the system of claim 3 and further teaches that while the system is in use, the second Lewis acid cation is present in the electrolyte salt solution (para [0033], “metal ions 122 may be present in solution ... For example, upon exposure to an electrical potential, anode 102 (e.g., Cu metal) may oxidize and release metal ion 122 (e.g., Cu(II)) into solution 118”).
Regarding claim 14, Hatton teaches the system of claim 3 and further teaches the electrolyte salt comprises a Mg-containing salt, a Ca-containing salt, and/or combinations thereof (para [0062], “electrolyte is a salt ... for example, an alkali metal salt or an alkaline metal salt... examples of cations include K+, Li+, Mg+2, Ca+2”).
Regarding claim 15, Hatton teaches the system of claim 1, and further teaches the first Lewis acid cation is K+, Li+, and/or combinations thereof (para [0062], “electrolyte is a salt ... for example, an alkali metal salt ... examples of cations include K+, Li+, ...”).
Regarding claim 19, Hatton teaches the system of claim 4 wherein the fluid source is a liquid electrolyte (para [0034], “solution contained in the system comprises ... electrolyte”).
Regarding claim 20, Hatton teaches an electrochemical system (figure 1 system 100; para [0005]), comprising:
a fluid source (para [0034], “solution contained in the system”) comprising:
an electrolyte salt comprising a first Lewis acid cation (para [0034], “solution contained in the system comprises ... electrolyte”; para [0062], “electrolyte is a salt ... for example, an alkali metal salt or an alkaline metal salt... examples of cations include K+, Li+, Mg+2, Ca+2, ...”; note, per instant specification pg 23 and 38, K+, Li+, Mg2+, and Ca2+ are all exemplary Lewis acid cations); and
a carbamic acid compound (figure 3; para [0034], “solution contained in the system comprises a complexation agent ... In a non-limiting example, the complexation agent is ethylenediamine ... CO2 308 from incoming feed gas comprising CO2 is absorbed by ethylenediamine generating carbamate 310”); and
an electrochemical cell comprising a positive electrode and a negative electrode (figure 1; para [0026], “System 100 may be an electrochemical cell. As illustrated in FIG. 1, system 100 comprises anode 102 ... and cathode 106”), wherein, upon charge of the electrochemical cell, the positive electrode is configured to produce a second Lewis acid cation (para [0034], “As the solution flows from the cathode in fluid communication with the anode (as described above) applied electrical potential 304b (e.g., continuously applied electrical potential) may oxidize Cu metal electrode 306b to Cu(II) ions 318”; note, Hatton teaches the electrode that releases the Cu2+ Lewis acid cation is metallic Cu and it is the anode (para [0032]-[0035])) that interacts with the carbamic acid compound to release CO2 from the carbamic acid compound (para [0034], “Upon oxidation of the Cu metal 306b (e.g., Cu metal electrode) to Cu(II) ions 318, Cu(II) may preferentially bind to ethylenediamine 310 to generate Cu(II)-ethylenediamine complex 302, thereby resulting the release of CO2 320 from carbamate 310”), and wherein the second Lewis acid cation is a stronger Lewis acid than the first Lewis acid cation (the second Lewis acid cation, Cu2+, is a stronger Lewis acid than the first Lewis acid cation (e.g. K+, Li+, Mg2+, or Ca2+) as evidenced by the fact that the Cu2+ displaced CO2 from the carbamic acid adduct and the first Lewis acid cation did not).
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 16-17 are rejected under 35 U.S.C. 103 as being unpatentable over Hatton.
Regarding claim 16, Hatton teaches the cell of claim 1. Hatton further teaches that the carbamic acid is the adduct of an amine complexation agent with carbon dioxide (para [0052], “complexation agent is an amine”; figure 3, when the complexation agent associates with CO2, CO2 adds at the amine site to form the corresponding carbamic acid; for instance in the illustration of figure 3 in which ethylenediamine is the complexation agent, the carbamic acid complex 310 is formed as a zwitterionic molecule of formula (R1)(R2)NHCOO wherein R1 is hydrogen and R2 is an ethylamine group).
Hatton further teaches that the complexation agent may be a molecule having the structure R3N, wherein each R is the same or different and is hydrogen or alkyl (para [0052]). It follows that, if a molecule (R1)2NH is selected as the complexation agent from among the broad genus of complexation agents disclosed in Hatton (para [0052]), the corresponding carbamic acid molecule that will be formed is (R1)2NHCOO, as claimed.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to select, from among the amines Hatton teaches are suitable for use in their method, an amine of the formula (R1)2NH, thereby arriving at a system in which the carbamic acid molecules is (R1)2NHCOO as claimed. The court has held that if an anticipated success is attained by a person pursuing one of a finite number of known options within their technical grasp, the outcome likely reflects ordinary skill and common sense, rather than inventiveness (see KSR Int'l Co. v. Teleflex Inc., 550 U.S. at 421, 82 USPQ2d at 1397 (2007); also see MPEP 2143(E) and case law discussed therein).
Regarding claim 17, Hatton teaches the system of claim 16 and further teaches the second Lewis acid cation is configured to interact with the carbamic acid compound to release CO2 from the carbamic acid compound (para [0032]-[0034], “Cu(II) may preferentially bind to ethylenediamine 310 to generate Cu(II)-ethylenediamine complex 302, thereby resulting the release of CO2 320 from carbamate 310”).
Hatton does not disclose that the release of CO2 from the (R1)2NCOOH molecule results in the generation of a compound of the formula (R1)2NH2+ and of a compound of formula (R1)2NCOO−. However, since the carbamic acid molecule (R1)2NHCOO suggested in Hatton is identical to the carbamic acid molecule as defined in the claim, it follows that the carbamic acid molecule of Hatton is configured to undergo the same reaction as claimed when a CO2 molecule is displaced therefrom. The courts have held that “[p]roducts of identical chemical composition cannot have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP 2112.
Claims 5 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Hatton as applied to claims 2 and 20 above, in view of US 2021/0062351 A1 to Voskian and Hatton (hereinafter “Voskian”).
Regarding claim 5, Hatton teaches the system of claim 2, and further teaches that the negative electrode is configured to intercalate the second Lewis acid cation (para [0067]-[0070]). However, Hatton does not teach the positive electrode is configured to intercalate the first Lewis acid cation (i.e. the Li+ or K+ ion).
Voskian, like Hatton, is directed to an electrochemical swing absorption system, which performs an electrochemical redox reaction upon a first electroactive mediator at a negative electrode, to actuate the mediator between a CO2-bonding state and a CO2-releasing state (para [0036], [0044]-[0049]). Voskian teaches that the electrochemical circuit is completed by a second redox reaction at the positive electrode (para [0102]), and in particular that a suitable redox reaction for this purpose is the intercalation and deintercalation of an alkali metal ion at the positive electrode (para [0105]). Voskian discloses that the alkali-intercalating electrode material may be any of a variety of known lithium battery (para [0105], Voskian identifies lithium transition metal oxides, and lithium iron phosphate as possible electrode materials).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Hatton by selecting, as the positive electrode, an electrode which intercalates and deintercalates the alkali metal ion that comprises Hatton’s first Lewis acid cation, based on Voskian’s teaching that, in a similar electrochemical CO2 capture device that similarly relies on a redox reaction at a first electrode to swing between CO2 capture mode and a CO2 release mode, the intercalation of an alkali metal ion at the opposing electrode is a suitable half cell reaction for completing the electrochemical circuit. The simple substitution of one known element for another (i.e., one counterelectrode material for another) is likely to be obvious when predictable results are achieved (i.e., reversible intercalation of the first Lewis acid cation) [MPEP § 2143(B)]. Furthermore, 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 [MPEP § 2144.07].
Regarding claim 21, Hatton teaches the system of claim 20, and further teaches that the positive electrode is configured to intercalate the second Lewis acid cation (para [0067]-[0069]). However, Hatton does not teach the negative electrode is configured to intercalate the first Lewis acid cation (i.e. the Li+ or K+ ion).
Voskian, like Hatton, is directed to an electrochemical swing absorption system, which performs an electrochemical redox reaction upon a first electroactive mediator at a first electrode, to actuate the mediator between a CO2-bonding state and a CO2-releasing state (para [0036], [0044]-[0049]). Voskian teaches that the electrochemical circuit is completed by a second redox reaction at the opposing electrode (para [0102]), and in particular that a suitable redox reaction for this purpose is the intercalation and deintercalation of an alkali metal ion (para [0105]). Voskian discloses that the alkali-intercalating electrode material may be any of a variety of known lithium battery (para [0105], Voskian identifies lithium transition metal oxides, and lithium iron phosphate as possible electrode materials).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Hatton by selecting, as the negative electrode, an electrode which intercalates and deintercalates the alkali metal ion that comprises Hatton’s first Lewis acid cation, based on Voskian’s teaching that, in a similar electrochemical CO2 capture device that similarly relies on a redox reaction at a first electrode to swing between CO2 capture mode and a CO2 release mode, the intercalation of an alkali metal ion at the opposing electrode is a suitable half cell reaction for completing the electrochemical circuit.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Hatton as applied to claim 2 above, in view of Voskian, and further in view of US 2012/0328936 A1 to Wessels et al (hereinafter “Wessels”).
Regarding claim 6, Hatton teaches the system of claim 2, and further teaches that the negative electrode is configured to intercalate the second Lewis acid cation (para [0067]-[0069]). However, Hatton does not teach the positive electrode comprises an electrode material that is configured to intercalate the first Lewis acid cation (i.e. the Li+ or K+ ion). Nor does Hatton teach the positive electrode comprises any particular alkali intercalation electrode material.
Voskian, like Hatton, is directed to an electrochemical swing absorption system, which performs an electrochemical redox reaction upon a first electroactive mediator at a negative electrode, to actuate the mediator between a CO2-bonding state and a CO2-releasing state (para [0036], [0044]-[0049]). Voskian teaches that the electrochemical circuit is completed by a second redox reaction at the positive electrode (para [0102]), and in particular that a suitable redox reaction for this purpose is the intercalation and deintercalation of an alkali metal ion at the positive electrode (para [0105]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Hatton by selecting, as the positive electrode, an electrode which intercalates and deintercalates the alkali metal ion that comprises Hatton’s first Lewis acid cation, based on Voskian’s teaching that, in a similar electrochemical CO2 capture device that similarly relies on a redox reaction at a first electrode to swing between CO2 capture mode and a CO2 release mode, the intercalation of an alkali metal ion at the opposing electrode is a suitable half cell reaction for completing the electrochemical circuit. The simple substitution of one known element for another (i.e., one counterelectrode material for another) is likely to be obvious when predictable results are achieved (i.e., reversible intercalation of the first Lewis acid cation) [MPEP § 2143(B)]. Furthermore, 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 [MPEP § 2144.07].
However, Voskian does not teach using Prussian blue, Prussian white, or an analogue thereof as the alkali intercalating electrode material.
Wessels is directed to the use of Prussian blue analogues as electrode materials for alkali-intercalating electrodes in secondary battery applications (para [0006]-[0010]. Wessels teaches that Prussian blue analogues offer particular advantages compared to other known alkali-intercalating materials such as the lithium metal oxides and lithium iron phosphate materials disclosed in Voskian, namely, that the Prussian blue analogue electrodes have greater durability and faster intercalation kinetics (figure 4; para [0053], [0095]-[0096]), they are inexpensive to synthesize in bulk, and are compatible with aqueous electrolyte, making them particularly suited to large scale devices (para [0101]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention, when selecting an alkali intercalating electrode material to use in the aqueous carbon-capture device of Hatton, to select a Prussian blue analogue, based on Wessels teaching that Prussian blue analogues operate effectively with aqueous electrolyte (note, Hatton at para [0060] discloses their electrolyte solvent is water) and that their durability and their price makes them particularly preferred over other intercalation electrodes in grid scale applications (para [0053], [0101]).
Claims 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Hatton as applied to claims 7 and 1 above, in view of US 2011/0186441 A1 to LaFrancois et al (hereinafter “LaFrancois”), and Boulamenti et al (“Production costs of the non-ferrous metals in the EU and other countries: Copper and zinc”, Resources Policy, 49, 112-118 (2016)).
Regarding claim 8, Hatton teaches the electrochemical system of claim 7. Hatton teaches the metal is preferably copper (para [0033]), and in alternative embodiments may be other metals such as tin, nickel, platinum, gold, silver (para [0056]). Hatton does not teach the metal comprises zinc (Zn), magnesium (Mg), calcium (Ca), and/or combinations thereof.
LaFrancois is similarly directed to an electrochemical-swing system for absorption and desorption of carbon dioxide, in which carbon dioxide is absorbed by capture solution comprising an amine and a Lewis acid metal cation, to form a carbamate complex (figure 1, CO2-containing gas stream 102 is contacted with amine solution in absorption column 100 to produce treated gas stream 104 and CO2-loaded absorption solution 106; para [0015]-[0016]). The CO2 loaded solution is then directed into an electrochemical cell (figure 1, cell 108), where the Lewis acid metal cation is electrochemically reduced, dissociating the carbamate and releasing CO2 (figure 2; para [0017]-[0019]). LaFrancois teaches that the Lewis acid metal cation may be the cation of any of copper, zinc, cobalt, nickel, aluminum, and magnesium (para [0024], claim 7).
Boulamenti teaches that the price of zinc is about 20-30% of the price of copper by weight (pg 112 abstract, “Our study compares production costs of ... copper and zinc”; para 118 left column para 2, “The average international prices of copper Grade A in the LME were 6244 EUR/t in 2012 and 5520 EUR/t in 2013, while for zinc settlement were 1439 and 1528 EUR/t for 2012 and 2013 respectively”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to substitute zinc in place of copper as the second Lewis cation in Hatton’s device, in light of LaFrancois’s teaching that zinc and copper are both suitable for a similar purpose in a similar device. The simple substitution of one known element for another (i.e., copper for zinc) is likely to be obvious when predictable results are achieved (i.e., similar device operation at lower cost) [MPEP § 2143(B)], and the selection of a known material based on its suitability for the intended use, is within the ambit of one of ordinary skill in the art [MPEP § 2144.07]. Motivation to make such a substitution might be cost savings, since (as taught e.g. in Boulamenti) zinc is significantly less expensive than copper.
Regarding claim 9, Hatton teaches the system of claim 1. However, Hatton’s second Lewis cation is Cu2+. Hatton does not teach wherein the second Lewis acid cation is Zn2+, Mg2+, Ca2+.
LaFrancois is similarly directed to an electrochemical-swing system for absorption and desorption of carbon dioxide, in which carbon dioxide is absorbed by capture solution comprising an amine and a Lewis acid metal cation, to form a carbamate complex (figure 1, CO2-containing gas stream 102 is contacted with amine solution in absorption column 100 to produce treated gas stream 104 and CO2-loaded absorption solution 106; para [0015]-[0016]). The CO2 loaded solution is then directed into an electrochemical cell (figure 1, cell 108), where the Lewis acid metal cation is electrochemically reduced, dissociating the carbamate and releasing CO2 (figure 2; para [0017]-[0019]). LaFrancois teaches that the Lewis acid metal cation may be the cation of any of copper, zinc, cobalt, nickel, aluminum, and magnesium (para [0024], claim 7).
Boulamenti teaches that the price of zinc is about 20-30% the price of copper by weight (pg 112 abstract, “Our study compares production costs of ... copper and zinc”; para 118 left column para 2, “The average international prices of copper Grade A in the LME were 6244 EUR/t in 2012 and 5520 EUR/t in 2013, while for zinc settlement were 1439 and 1528 EUR/t for 2012 and 2013 respectively”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to substitute Zn2+ in place of Cu2+ as the second Lewis cation in Hatton’s device, in light of LaFrancois’s teaching that zinc and copper are both suitable for a similar purpose in a similar device. The simple substitution of one known element for another (i.e., copper for zinc) is likely to be obvious when predictable results are achieved (i.e., similar device operation at lower cost) [MPEP § 2143(B)], and the selection of a known material based on its suitability for the intended use, is within the ambit of one of ordinary skill in the art [MPEP § 2144.07]. Motivation to make such a substitution might be cost savings, since (as taught e.g. in Boulamenti) zinc is significantly less expensive than copper.
Claims 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over Hatton as applied to claim 4 above, and further in view of US 2016/0038872 A1 to Calabro et al (hereinafter “Calabro”).
Regarding claims 10-11, Hatton teaches the system of claim 4 but does not teach the fluid source comprises a nonaqueous solvent (as required by claim 10), or wherein the solvent comprises dimethyl sulfoxide (DMSO), dimethylacetamide (DMA), N-methylpyrrolidone (NMP) or combinations thereof (as required by claim 11).
Calabro is directed to a capture-and-regeneration method for separating CO2 from a gas stream, and to amine-based absorbent solutions for use in such a method. Calabro teaches, whereas absorbent solutions of the prior art typically use aqueous solutions of alkanolamines (para [0004]-[0005]), they instead use nonaqueous solutions of aliphatic amines (para [0010]-[0014]). Calabro teaches that their nonaqueous CO2 capture solution is advantageous because, compared to an aqueous capture solution, their solution is able to capture more CO2 molecules for a given amount of amine (para [0014]; pg 12 Table 1; para [0101]-[0110]). In particular Calabro teaches using 2-ethoxyethylamine as the capture amine and DMSO as the solvent (para [0044], [0056], [0101]-[0110]). Calabro teaches that the capture amine reacts with CO2 to form the corresponding carbamic acid adduct (para [0035]-[0038]), such that when 2-ethoxyethylamine is employed as the capture amine, the CO2 loaded capture solution comprises (2-ethoxyethyl)carbamic acid (figure 3-5).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Hatton by substituting, in place of Hatton’s aqueous amine capture solution, a solution of 2-ethoxyethylamine in DMSO as the CO2 capture solution, such that the fluid source in the electrochemical cell is a solution of a carbamic acid molecule in DMSO solvent, motivated by Calabro’s teaching that organic solutions are effective CO2 capture solutions which are able to achieve higher CO2 loading than comparable aqueous amine capture solutions (para [0014], [0101]-[0110], pg 12 Table 1).
Regarding claim 18, Hatton teaches the electrochemical system of claim 1 but does not teach the carbamic acid compound comprises carbamic acid, (2-methoxyethyl)carbamic acid, (2-ethoxyethyl)carbamic acid, and/or combinations thereof.
Calabro is directed to a capture-and-regeneration method for separating CO2 from a gas stream, and to amine-based absorbent solutions for use in such a method. Calabro teaches, whereas absorbent solutions of the prior art typically use aqueous solutions of alkanolamines (para [0004]-[0005]), they instead use nonaqueous solutions of aliphatic amines (para [0010]-[0014]). Calabro teaches that their nonaqueous CO2 capture solution is advantageous because, compared to an aqueous capture solution, their solution is able to capture more CO2 molecules for a given amount of amine (para [0014]; pg 12 Table 1; para [0101]-[0110]). In particular Calabro teaches using 2-ethoxyethylamine as the capture amine in dimethyl sulfoxide solvent (para [0044], [0056], [0101]-[0110]). Calabro teaches that the capture amine reacts with CO2 to form the corresponding carbamic acid adduct (para [0035]-[0038]), such that when 2-ethoxyethylamine is employed as the capture amine, the CO2 loaded capture solution comprises (2-ethoxyethyl)carbamic acid (figure 3-5).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Hatton by substituting, in place of Hatton’s aqueous amine capture solution, a solution of 2-ethoxyethylamine in organic solvent (e.g. DMSO) as the CO2 capture solution, such that the CO2-loaded fluid source fed into the electrochemical cell is a solution of (2-ethoxyethyl)carbamic acid, motivated by Calabro’s teaching that organic solutions of 2-ethoxyethylamine are effective CO2 capture solutions which are able to achieve higher CO2 loading than aqueous amine capture solutions (para [0014], [0101]-[0110], pg 12 Table 1).
Regarding claims 55-57, Hatton teaches the systems of claim 1, 4, and 20 respectively but does not teach the fluid source comprises a nonaqueous solvent that stabilizes the carbamic acid as compared to water.
Calabro is directed to a capture-and-regeneration method for separating CO2 from a gas stream, and to amine-based absorbent solutions for use in such a method. Calabro teaches, whereas absorbent solutions of the prior art typically use aqueous solutions of alkanolamines (para [0004]-[0005]), they instead use nonaqueous solutions of aliphatic amines (para [0010]-[0014]). Calabro teaches that their nonaqueous CO2 capture solution is advantageous because, compared to an aqueous capture solution, their solution is able to capture more CO2 molecules for a given amount of amine (para [0014]; pg 12 Table 1; para [0101]-[0110]). In particular Calabro teaches using 2-ethoxyethylamine as the capture amine and DMSO as the solvent (para [0044], [0056], [0101]-[0110]). Calabro teaches that the capture amine reacts with CO2 to form the corresponding carbamic acid adduct (para [0035]-[0038]), such that when 2-ethoxyethylamine is employed as the capture amine, the CO2 loaded capture solution comprises (2-ethoxyethyl)carbamic acid (figure 3-5).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Hatton by substituting, in place of Hatton’s aqueous amine capture solution, a solution of 2-ethoxyethylamine in DMSO as the CO2 capture solution, such that the fluid source in the electrochemical cell is a solution of a carbamic acid molecule in DMSO solvent, motivated by Calabro’s teaching that organic solutions are effective CO2 capture solutions which are able to achieve higher CO2 loading than comparable aqueous amine capture solutions (para [0014], [0101]-[0110], pg 12 Table 1).
Note that the instant specification (at pg 12 lines 21-27) names DMSO as an example of a suitable nonaqueous solvent that may stabilize the carbamic acid compound as compared to water. Therefore it is understood that Hatton, modified in view of Calabro to use DMSO as the solvent, meet the limitations of claims 55-57.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Hatton as applied to claim 20 above, in view of LaFrancois and Boulamenti, and further in view of Alfaruqi et al (“Electrochemical Zinc Intercalation in Lithium Vanadium Oxide: A High-Capacity Zinc-Ion Battery Cathode”, Chemistry of Materials, 29, 1684-1694 (2017)).
Regarding claim 22, Hatton teaches the system of claim 20, and further teaches that the positive electrode is configured to intercalate the second Lewis acid cation (para [0067]-[0070]). However Hatton’s second Lewis acid cation is Cu2+ and Hatton’s positive electrode is a copper-intercalation electrode material (para [0067]-[0070]). Hatton does not disclose that the positive electrode material is ZnLiV3O8 or any one of the other materials recited in claim 22.
LaFrancois is similarly directed to an electrochemical-swing system for absorption and desorption of carbon dioxide, in which carbon dioxide is absorbed by capture solution comprising an amine and a Lewis acid metal cation, to form a carbamate complex (figure 1, CO2-containing gas stream 102 is contacted with amine solution in absorption column 100 to produce treated gas stream 104 and CO2-loaded absorption solution 106; para [0015]-[0016]). The CO2 loaded solution is then directed into an electrochemical cell (figure 1, cell 108), where the Lewis acid metal cation is electrochemically reduced, dissociating the carbamate and releasing CO2 (figure 2; para [0017]-[0019]). LaFrancois teaches that the Lewis acid metal cation may be the cation of any of copper, zinc, cobalt, nickel, aluminum, and magnesium (para [0024], claim 7).
Boulamenti teaches that the price of zinc is about 20-30% the price of copper by weight (pg 112 abstract, “Our study compares production costs of ... copper and zinc”; para 118 left column para 2, “The average international prices of copper Grade A in the LME were 6244 EUR/t in 2012 and 5520 EUR/t in 2013, while for zinc settlement were 1439 and 1528 EUR/t for 2012 and 2013 respectively”).
Alfaruqi discloses an electrode comprising ZnLiV3O8, and its use as an intercalation cathode for a zinc-ion secondary battery. (pg 1684 abstract; pg 1685 figure 1a; pg 1686 left column para 3 – right column para 1). Alfaruqi teaches that this cathode material is able to intercalate and de-intercalate zinc with nearly 100% coulombic efficiency (pg 1687 figure 2; pg 1688 left column para 2 – pg 1689 left column para 1; pg 1692 right column para 2 – pg 1693 left column para 1), implying that zinc intercalation electrode made of this material will have long operation lifetimes.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to substitute Zn2+ ions in place of Cu2+ ions as the second Lewis cation in Hatton’s device, in light of LaFrancois’s teaching that zinc and copper are both suitable for a similar purpose in a similar device. Motivation to make such a substitution might be cost savings, since (as taught e.g. in Boulamenti) zinc is significantly less expensive than copper. It also would have been obvious one skilled in the art, when modifying Hatton’s Lewis acid cation from copper to zinc, to modify Hatton’s positive electrode from a copper-intercalation electrode material to a known zinc-intercalation electrode material of the prior art, and in so doing, to select e.g. ZnLiV3O8 as the electrode material based on Alfaruqi’s teaching that this material intercalates zinc with nearly perfect Coulombic efficiency (pg 1692 right column para 2 – pg 1693 left column para 1). The simple substitution of one known element for another (i.e., zinc in place of copper, and a known zinc-intercalation electrode material for the copper-intercalating electrode) is likely to be obvious when predictable results are achieved (i.e., similar device operation at lower cost) [MPEP § 2143(B)]. The selection of a known material based on its suitability for the intended use is within the ambit of one of ordinary skill in the art [MPEP § 2144.07].
Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Hatton as applied to claim 20 above, in view of Voskian, and further in view of US 2007/0238023 A1 to Gorshkov et al (hereinafter “Gorshkov”).
Regarding claim 23, Hatton teaches the system of claim 20. Hatton further teaches that the positive electrode may be an intercalation electrode configured to intercalate the second Lewis acid cation (para [0067]-[0069]). However, Hatton does not teach the negative electrode is a material such as Li4Ti5O12 or TiO2, i.e. an intercalation electrode material configured to intercalate the first Lewis acid cation (i.e. the Li+ or K+ ion).
Voskian, like Hatton, is directed to an electrochemical swing absorption system, which performs an electrochemical redox reaction upon a first electroactive mediator at a negative electrode, to actuate the mediator between a CO2-bonding state and a CO2-releasing state (para [0036], [0044]-[0049]). Voskian teaches that the electrochemical circuit is completed by a second redox reaction at the opposing electrode (para [0102]), and in particular that a suitable redox reaction for this purpose is the intercalation and deintercalation of an alkali metal ion at that electrode (para [0105]). Voskian discloses that the alkali-intercalating electrode material may be any of a variety of known lithium-intercalating electrode materials (para [0105]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Hatton by selecting, as the negative electrode, an electrode which intercalates and deintercalates the alkali metal ion that comprises Hatton’s first Lewis acid cation, based on Voskian’s teaching that, in a similar electrochemical CO2 capture device that similarly relies on a redox reaction at a first electrode to swing between CO2 capture mode and a CO2 release mode, the intercalation of an alkali metal ion at the opposing electrode is a suitable half cell reaction for completing the electrochemical circuit.
Voskian does not teach that the alkali-intercalating electrode material comprises Li4Ti5O12 or TiO2.
Gorshov teaches that lithium titanate (Li4Ti5O12) is a lithium intercalating material which attracts interest in the art for use as an anode material in lithium secondary battery applications (para [0009]). Particular advantages of Li4Ti5O12 include (a) excellent cycleability, i.e., many cycles of charging and discharging may occur without deterioration of the cells (para [0010]), (b) a discharge voltage that remains relatively constant as lithium is added or removed from the electrode (para [0011]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention, when selecting a lithium-intercalating electrode material for use in the positive electrode of Hatton’s device as suggested by Voskian, to select Li4Ti5O12, based on the prior art’s teaching (as summarized in the background section of Gorshov, para [0009]-[0012]) that Li4Ti5O12 is an attractive material choice for lithium-intercalating positive electrodes due to its constant discharge voltage and its long cycle life.
Response to Arguments
Applicant's arguments filed 3 September 2026 have been fully considered but they are not persuasive.
Applicant traverses the 102 and 103 rejections over Hatton on the grounds that the claims’ recitation of a “carbamic acid compound” is patentably distinct from Hatton’s disclosure of a “carbamate” species.
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These arguments are unpersuasive because a specific “carbamate” disclosed by the reference and forming part of the basis for the §102 rejection, is this molecule, drawn in Hatton at figure 3:
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... which is clearly a tautomeric form of (2-aminoethyl) carbamic acid:
... which is a carbamic acid compound, as claimed.
As such the §102 rejection is maintained.
Conclusion
THIS ACTION IS MADE FINAL. 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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
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/ANDREW KOLTONOW/Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795
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