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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 12/04/2025 has been entered.
Election/Restrictions
Claims 11 and 12 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.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 12/26/2024.
Examiner Note
It is noted that Claim 3 is a properly-formed multiple dependent claim. Per MPEP 608.01(n)(I)(F), such claims are examined as individual claims, with reference to the specific dependence in each embodiment. In the instant case, Claim 3 will be examined twice – once with respect to Claim 3 depending on Claim 1, referred to as Claim 3/1, and once with respect to Claim 3 depending on Claim 2, referred to as Claim 3/2. Furthermore, with regard to Claim 4, which depends on Claim 3, the claim will be similarly examined using the notation 4/3/1 and 4/3/2.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
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.
Claim(s) 1-2, 8-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Constantz et al. (US 2011/0091955 A1), hereinafter ‘Constantz’.
Regarding Claim 1, Constantz discloses a method for sequestering carbon ([0019]) comprising the steps of:
spraying a solution containing calcium ions into a reactor containing supercritical carbon dioxide to form a slurry of calcium carbonate ([0005], [0031]: the methods of the invention include contacting a volume of an aqueous solution of divalent cations with a source of CO2 to produce a composition comprising a metastable carbonate, the metastable carbonate selected from the group including calcium carbonate and the divalent cations selected from a group including calcium ([0043]); [0032], the “source of CO2” includes any convenient CO source, including supercritical CO2; [0119]: a spray tower of the invention is configured to spray a solution (e.g., aqueous solution of divalent cations) into a medium comprising CO2;);
collecting the calcium carbonate from the bottom of the reactor (Figure 6, (612), [0126]: slurry comprising carbonate product is collected from the bottom of the reactor), and
recycling spent solution from the slurry ([0100]: Supernatant resulting from a liquid-solid separation apparatus or an assembly of liquid-solid separation apparatus may be recirculated through the liquid-solid separation apparatus or assembly of liquid solid separation apparatus to increase separation efficiency – given this, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to recycle spent solution from the slurry, considered the supernatant within the disclosure of Constantz, in order to increase separation efficiency).
Regarding Claim 2, Constantz discloses a liquid outlet for pressure release of solution ([0126]), which is considered a back pressure regulator.
Regarding Claim 8, Constantz discloses that the sprayed solution is aqueous ([0031]: “…the methods of the invention include contacting a volume of an aqueous solution of divalent cations…”).
Regarding Claim 9, while Constantz does not disclose that carbon dioxide is provided in excess for reaction with the calcium solution, Constantz does disclose that there may be sufficient carbon dioxide in the divalent cation-containing solution to precipitate significant amounts of carbonate- and/or bicarbonate-containing precipitation material, but that additional carbon dioxide may be used ([0031]) – additional carbon dioxide in this context is considered an excess of that required to react all available calcium ions. Therefore, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to utilize an excess amount of carbon dioxide in the inventive process of Constantz in order to precipitate significant amounts of carbonate- and/or bicarbonate-containing precipitation material as disclosed.
Regarding Claim 10, the prior art meets the limitations of Claim 1 as shown above. Further, Constantz discloses the solution is sprayed using an injector nozzle provided at the top section of the reactor, having a working pressure of around 80-400 bar (Fig. 6: part 605 corresponds to the aqueous solution inlet, located at the top section of the reactor; [0119]: “A spray tower of the invention may comprise a multitude of stages and/or spray inlets (e.g., nozzles) at various locations throughout the tower…[o]perationally, spray towers of the invention are configured to spray a solution (e.g., aqueous solution of divalent cations such as seawater and/or brine and/or recirculated water and/or fresh water and/or water containing the proton-removing agent) into a medium comprising a CO2-containing containing gas…”. In configuring such a spray tower, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to configure a nozzle for providing aqueous solution of divalent cations at the top of the reactor, as the drawing of the invention shows introducing such a solution from the top of the reactor; [0096]: “the processor…may include any of a number of different components…such components may be used to…pressurization components (e.g., for operating under pressurized conditions…” In the use of a spray tower as described above, utilizing supercritical CO2, the operating pressure of the reactor must be at or above the critical pressure of CO2, 7.38 MPa, or 73.8 bar. This implies a suitable range of operation for the process as modified above to be greater than or equal to 73.8 bar. Further, the spray nozzle must necessarily provide liquid to the reactor at or above the operating pressure in order for liquid to flow out of the nozzle – therefore, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to operate the nozzle at a pressure greater than or equal to 73.8 bar, which overlaps with and makes obvious the instant claimed range. As set forth in MPEP 2144.05, in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art,” a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) – as such, the instant claimed range is obvious over the prior art range).
Claim(s) 3-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Constantz et al. (US 2011/0091955 A1), hereinafter ‘Constantz’, in view of Folger et al. (Residence Time Distributions, University of Michigan, 2017).
Regarding Claims 3/1 and 3/2, Constantz is silent regarding adjusting the regulator such that the slurry continuously flows out of the reactor via the outlet while maintaining a predetermined height of slurry within the reactor.
However, Constantz discloses continuous operation of the inventive process ([0133]). Continuous operation of a process in a tank such as that of Constantz (Figure 6) requires mass flow equilibrium, in which the rate of material fed into the reactor is equal to the rate of material leaving the reactor – if a continuously operated reactor is not operated in this way, the reactor will either run dry due to overdrawing from the reactor, or overflow due to accumulation. Therefore, the slurry height of the reactor of Constantz must be maintained at a specific, static height in order to operate continuously.
Further, the height of reactants in a reactor is a function of the residence time, or the amount of time a substance remains within a reactor (see Folger, 16-4, paragraph 2) – such a residence time is defined as a ratio of the reaction volume and the flow rate at steady state (see Folger, 16-12, Mean Residence Time).
Further, in the case of the reactor of Constantz (Figure 6), the volume of the reactor would be defined, assuming the cross-section shown is of a cylindrical reactor, by VR=πr2hR – given the constant radius of the reactor, the reaction volume is a function of the height of the reactor volume h, and therefore the residence time is a function of the height of reactants in the reactor. Further, the residence time of a reactor is a quantity known to significantly affect its performance in terms of conversion and product distribution (see Folger, 16-4, paragraph 3). Therefore, the residence time is a variable that may be modified in order to achieve the ideal conversion rate of the reactor, and this modification in turn would result in a particular slurry height in the reactor.
Lastly, Constantz discloses that the liquid outlet 606 is configured for pressure release of solution 612 – considering Figure 6, it is clear that release from this outlet lowers the height of liquid in the reactor, thereby lowering the pressure at this outlet by reducing the height of the liquid above it, since the pressure at a point in a fluid is a function of its height (P = ρgh, where P is the pressure and h is the height of the fluid). The flow out of this outlet is controlled by a valve, which is disclosed as resulting in regulating the pressure inside the contacting chamber (602) so as not to exceed the pressure limits the apparatus may withstand, and for better control the pressure release of the solution (612) containing hydrated CO2 (e.g., bicarbonates and/or carbonates) ([0127]). Therefore, the pressure release of the solution within the reactor is modulated in the process of Constantz by adjusting this outlet, and more specifically, the height of the slurry in the reactor.
Therefore, it would be obvious to one of ordinary skill to adjust the valve on the liquid outlet of the reactor of Constantz in order to maintain a predetermined height in the reactor – doing so would ensure proper steady state continuous operation of the unit without dryout or overflow, would regulate the residence time of the reactants, and regulate the pressure of release of the outlet.
Regarding Claim 4/3/1 and 4/3/2, Constantz discloses that the inventive process produces particles having a size between 0.1 and 100 microns ([0005]), which is inherently achieved by configuring the reaction apparatus of Constantz, including configuring the liquid outlet valve for pressure release of solution as discussed above. Therefore, configuration of the liquid outlet for pressure release of solution to achieve the disclosed particle size of calcium carbonate is considered varying the average particle size distribution of the calcium carbonate by adjusting the back pressure regulator, resulting in the particle size achieved by Constantz.
Regarding Claim 5, Constantz does not disclose the height of the slurry being maintained at around 10% of the height of the reactor.
However, the height of reactants in a reactor is a function of the residence time, or the amount of time a substance remains within a reactor (see evidentiary reference Folger, 16-4, paragraph 2) – such a residence time is defined as a ratio of the reaction volume and the flow rate at steady state (see evidentiary reference Folger, 16-12, Mean Residence Time). Further, in the case of the reactor of Constantz (Figure 6), the volume of the reactor would be defined, assuming the cross-section shown is of a cylindrical reactor, by VR=πr2hR – further, given the constant radius of the reactor, the reaction volume is a function of the height of the reaction volume h, and therefore the residence time is a function of the height of reactants in the reactor. Further, the residence time of a reactor is a quantity known in the art to significantly affect its performance in terms of conversion and product distribution (see evidentiary reference Folger, 16-4, paragraph 3). Therefore, the residence time is a variable that may be modified in order to achieve the ideal conversion rate of the reactor, and this modification in turn would result in a particular slurry height in the reactor.
Therefore, as the residence time of reactants in a reactor is a variable that can be modified, among others, by adjusting the slurry height in the reactor, the precise reactor filling height would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed amount cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the slurry height in the reactor of Constantz to obtain the desired residence time that would achieve the ideal conversion of reactants, since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
Claim(s) 6-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Constantz et al. (US 2011/0091955A1), hereinafter ‘Constantz’, as evidenced by Cheih (Strong Acids and Strong Bases, LibreTexts, 2021 per earliest Wayback Machine crawl).
Regarding Claim 6, the prior art meets the limitations of Claim 1 as shown above. Further, Constantz discloses the source of divalent cations includes any medium containing alkaline earth metals such as calcium, and further discloses the particular source of such ions is not particularly limited ([0043]). Further, calcium hydroxide is one of six strong bases which are known to fully dissociate in water to produce divalent calcium (see evidentiary reference Chieh, Strong Bases). Therefore, given that calcium hydroxide is well known in the art to readily produce divalent calcium ions, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to use calcium hydroxide as the source of divalent cations in the disclosure of Constantz.
Regarding Claim 7, the prior art meets the limitations of Claim 1 as shown above. Further, Constantz discloses the use of calcium oxide in the reaction to produce calcium carbonate ([0043]: lime is disclosed as a suitable source of divalent cations – lime is also known as calcium oxide; further, said calcium oxide will be at least partially undissolved in said solution, per its solubility in water).
Further regarding Claim 7, while Constantz does not disclose the use of a solution comprising both calcium hydroxide and calcium oxide in the reaction to produce calcium carbonate as discussed above, calcium hydroxide and calcium oxide would both act as a source of divalent cations within the context of Constantz to react with carbon dioxide to produce calcium carbonate, given that both dissociate in water to produce Ca2+ (see evidentiary reference Chieh, Strong Bases). Therefore, given that calcium hydroxide and calcium oxide would function equivalently as a reactant to react with carbon dioxide to produce calcium carbonate, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to combine calcium hydroxide and calcium oxide to produce a mixture capable of also reacting with carbon dioxide to produce calcium carbonate. It is prima facie obvious to combine two compositions, each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose…[T]he idea of combining them flows logically from their having been individually taught in the prior art." In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980).
Response to Arguments
Applicant’s arguments, filed 12/04/2025, are acknowledged.
With respect to arguments with regard to objections to and the rejection of the claim(s) under section 112(a), 112(b), the arguments have been fully considered and are persuasive. These rejections have been withdrawn.
With respect to arguments in regard to prior art rejections of Claims 3-4 under section 103, Applicant’s arguments have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made under section 103 in view of Constantz.
Further, Applicant’s arguments with respect to the rejection of the rest of the claims are not persuasive.
Applicant argues “…Claim 1 defines formation based on a specific mode of physical contact between atomized calcium-ion solution and supercritical CO₂. This is neither disclosed nor suggested by Constantz. Constantz forms metastable carbonates through a catalytic hydration process (see paragraph [0043]. Constantz relies on hydrated CO₂ in aqueous solution and catalyst-mediated formation. Furthermore, Constantz's "spray towers" are not configured to produce immediate surface-interface precipitation; they are designed to maximize gas absorption efficiency. Thus, even if Constantz generally discusses mixing Ca²⁺ and CO2, it does not teach the claimed mode of contacting, nor does it render it obvious.”
This is not considered persuasive. Firstly, [0043] of Constantz, relied upon by Applicant to show the reference does not meet the claimed contact method, discloses “the methods and systems of the invention include contacting a volume of an aqueous solution of divalent cations with a source of CO2…”. This clearly identifies contacting a source of CO2 to form a reactant, as claimed. Constantz clearly identifies a suitable source of CO2 as being supercritical CO2, as shown above. While one embodiment of Constantz does embody the use of hydrated CO₂ in aqueous solution, the reference does not require that CO2 be provided exclusively in the form of an aqueous solution.
Further, Applicant argues “the process conditions for high-yield carbonation in supercritical media are not routine variables.”
There is no evidence to support this claim. Arguments of counsel cannot take the place of evidence where evidence is required – see MPEP 2145.
Further, Applicant argues “In supercritical carbonation systems, slurry height directly impacts droplet residence-time distribution, which determines supersaturation level, which in turn controls CaCO₃ polymorph formation and crystal habit. These interdependencies are nonlinear and non-routine and they are not predictable from Folger. There is no teaching or suggestion in Folger to maintain the slurry at around 10% of reactor height, which is a specific operating requirement of the present invention.”
This is not persuasive, as the reactor height is shown by the prior art to be tied to several results, including residence time as discussed above, such that routine optimization of the reactor height is prima facie obvious. While the particular claimed reactor height may have unexpected results or criticality as argued, Applicant has not provided evidence of such effects commensurate in scope with the instant invention persuasive in overcoming this prima facie showing of obviousness above. As set forth in MPEP 716.02(d), whether unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, “objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support”. In other words, the showing of unexpected results must be reviewed to see if the results occurred over the entire claimed range, In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980). Applicants have not provided data to show that the unexpected results do in fact occur over the entire claimed range of the claim.
Further, Applicant argues “… Constantz does not teach using Ca(OH)₂ or CaO in direct atomized contact with supercritical CO2 under the claimed operating conditions. Constantz and Cheih show that CaO/Ca(OH)₂ can generate Ca²⁺ in water, but neither reference addresses atomized spray behavior in supercritical conditions, interfacial carbonation kinetics, or precipitation pathway differences between CaO and Ca(OH)₂ mixtures.”
This is not persuasive – Constantz discloses providing divalent cations for carbonate formation from media containing alkaline-earth metals, expressly including calcium, as shown above. Calcium hydroxide is a strong base that readily and fully dissociates in water to yield divalent calcium, Ca2+. Those factors indicated by Applicant (addresses atomized spray behavior in supercritical conditions, interfacial carbonation kinetics, or precipitation pathway differences between CaO and Ca(OH)₂ mixtures do not negate the fact that calcium hydroxide would be considered by an ordinary artisan as a material reasonably capable of readily providing divalent ions within the process of Constantz. There is no evidence that supercritical conditions, interfacial carbonation kinetics, or precipitation pathway differences would negate the ability of calcium hydroxide to provide calcium ions as required by the process.
Conclusion
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/L.E.L./Examiner, Art Unit 1738
/ANTHONY J ZIMMER/Supervisory Patent Examiner, Art Unit 1736