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 .
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 3-15 and 18-19 are rejected under 35 U.S.C. 103 as being unpatentable over WO 2018206235 A1 (henceforth referred to as "Schjodt") in view of "Electrolysis of carbon dioxide in Solid Oxide Electrolysis Cells" by Ebbesen and Mogensen in the Journal of Power Sources Vol. 193, Issue 1, Aug. 2009 Pages 349-358 (henceforth referred to as "Ebbesen") and WO 2014154253 A1 (henceforth referred to as "Jakobsson").
In regard to claim 1, Schjodt teaches:
On page 11 lines 11-13, a fuel gas stream falling within the claimed 70-100 vol% CO2 and 0-30 vol% CO with a mole fraction of CO within 0-0.3.
The SOEC on page 11, lines 11-17 with a description of the cathode side. The specification of the present application refers to the cathode as the “fuel side” and the anode as the “oxy side” and a SOEC with a cathode must also have an anode.
The fuel gas stream temperature is in the range from 600 to 1000 degrees C on page 11, lines 11-13.
A fuel flow rate of 100 Nl/min on page 11 lines 12-13. This doesn’t directly translate to “space velocity” but the volume of Schjodt’s cell stack is not constrained and a person having ordinary skill in the art would have been able to modify the cell to have the space velocity of the fuel fit within the range of 2 to 30 1/s. As per MPEP 2144.04 IV A, changes in size/proportion are not patententably distinct.
An electrolysis current of 50 A on page 11 lines 13-14. Due to the lack of clear definition of the area of the cells, a person having ordinary skill in the art would have been able to design the cells such that the current density was in the range from -0.2 A/cm^2 to -1A/cm^2. As per MPEP 2144.04 IV A, changes in size/proportion are not patententably distinct.
Schjodt fails to teach:
The presence of a flush gas stream and consequently the heating and flow rate of said flush gas stream.
A selection of parameters to keep the coking potential less than -15.
Ebbesen teaches in the introduction section that “The regions for catalytic formation of coke in SOCs have been treated in great details and it was shown that formation of coke occur at very high CO concentrations only. At realistic CO2/CO concentrations during CO2 electrolysis the equilibrium of the Boudouard reaction is shifted towards CO, and coke will therefore not be formed catalytically during electrolysis.” Therefore, the selection of parameters to prevent coking would have been known to a person having ordinary skill in the art.
Jakobsson teaches on page 4 lines 9-14 to use air, N2, or CO2 as a flush gas on the oxygen side (anode) of the SOEC with the stated advantages of reducing oxygen concentration and related corrosive effects as well as providing a means of feeding energy into the SOEC. It would have been obvious to a person having ordinary skill in the art to combine the SOEC of Schjodt with the flush gas stream of Jakobsson to reduce the corrosive effects. The flush stream would then be at the temperature range of the fuel stream of Schjodt which is within 600 to 1000 degrees C. The space velocity of the flush gas in the same way as the fuel gas depends on the volume of Schjodt’s cell stack, which is not constrained. A person having ordinary skill in the art would have been able to modify the cell to have the space velocity of the flush gas fit within the range of 0.1 to 20 1/s. As per MPEP 2144.04 IV A, changes in size/proportion are not patententably distinct.
In regard to claim 3, Ebbesen teaches in the introduction section that “The regions for catalytic formation of coke in SOCs have been treated in great details and it was shown that formation of coke occur at very high CO concentrations only. At realistic CO2/CO concentrations during CO2 electrolysis the equilibrium of the Boudouard reaction is shifted towards CO, and coke will therefore not be formed catalytically during electrolysis.” Therefore, the selection of parameters to prevent coking would have been known to a person having ordinary skill in the art.
In regard to claim 4, Schjodt teaches on page 11 lines 15-17 that the output from their SOEC stack is 26% CO and 74% CO2 which is within the claimed range of 15-95 vol% CO.
In regard to claim 5, Schjodt teaches on page 11 lines 11-13 a fuel gas stream consisting of CO2 and CO within 70-100 vol% CO2 and 0-30 vol% CO. The ranges claimed overlap with the prior art’s ranges so the claimed ranges are rendered obvious.
In regard to claim 6, Jakobsson teaches at claim 13 that a configuration of the SOEC where CO2 from a gas separation outlet still containing some CO is sent back to the fuel stream. Jakobsson’s initial fuel stream is 100% CO2 and the recycled stream, as described on page 11 lines 1-6, will have some small amount of CO. This small amount of CO would provide a fuel gas stream consisting of 88-98 vol. % CO2 and 1-12 vol. % CO.
In regard to claim 7, Jakobsson teaches on page 4 lines 9-14 to use air, N2, or CO2 as a flush gas.
In regard to claim 8, Schjodt teaches on page 11 lines 11-17 that there is a fuel stream fed in and a product gas that exits the cathode side which would require an inlet and an outlet.
In regard to claim 9, Jakobsson teaches on page 4 lines 9-14 to use air, N2, or CO2 as a flush gas on the oxygen side (anode) of the SOEC and consequently this would require an inlet and an outlet.
In regard to claim 10, Jakobsson teaches on page 11 lines 27-30 that the outlet stream from the oxygen side of the SOEC can be connected to an oxidation unit, which requires collecting the oxygen enriched flush gas stream.
In regard to claim 11, Jakobsson teaches on page 1 lines 24-26 that the product stream containing CO mixed with CO2 is subjected to a separation process, which requires the CO enriched product stream to be collected.
In regard to claim 12, Jakobsson teaches in the abstract the product stream containing CO mixed with CO2 is subjected to a separation process. This would separate the stream into a CO enriched stream and a CO2 enriched stream.
In regard to claim 13, Jakobsson teaches in claim 12 that the CO2 from the separation unit is recycled into the fuel gas stream.
In regard to claim 14, Ebbesen in section 2.2 teaches the use of nickel foil electrodes in contact with nickel gas distributors on the anode and cathode sides as indicated by Ebbesen’s figure 2 as well as in contact with a power supply to function as an electrode in the cell.
In regard to claim 18, Schjodt teaches on page 17 lines 18-30 that the SOEC stacks are susceptible to breaking if individual cells break. This teaches that the stacks of Schjodt comprise a plurality of electrolysis cells arranged in a stack.
In regard to claim 19, as addressed by claim 1, the gas stream and flush stream are present and supplied through the stack during operation as addressed by the prior art. As for maintaining a coking potential less than or equal to -15, by nature of avoiding coking as addressed in claim 1, the combination of parameters required to meet the claim would have been known to a person having ordinary skill in the art.
In regard to claim 15,
i. Schjodt teaches on page 11 lines 11-13, a fuel gas stream falling within the claimed 70-100 vol% CO2 and 0-30 vol% CO with a mole fraction of CO within 0-0.3.
iii. Schjodt teaches the fuel gas stream temperature is in the range from 600 to 1000 degrees C on page 11, lines 11-13.
iv. Schjodt teaches an electrolysis current of 50 A on page 11 lines 13-14. Due to the lack of clear definition of the area of the cells, a person having ordinary skill in the art would have been able to design the cells such that the current density was in the range from -0.2 A/cm2 to -1A/cm2. As per MPEP 2144.04 IV A, changes in size/proportion are not patententably distinct.
Schjodt fails to teach the use of a flush gas as well as a method for selecting operating conditions to prevent coking.
Jakobsson teaches on page 4 lines 9-14 to use air, N2, or CO2 as a flush gas on the oxygen side (anode) of the SOEC with the stated advantages of reducing oxygen concentration and related corrosive effects as well as providing a means of feeding energy into the SOEC. It would have been obvious to a person having ordinary skill in the art to combine the SOEC of Schjodt with the flush gas stream of Jakobsson to reduce the corrosive effects. The flush stream would then be at the temperature range of the fuel stream of Schjodt which is within 600 to 1000 degrees C. The space velocity of the flush gas in the same way as the fuel gas depends on the volume of Schjodt’s cell stack, which is not constrained. A person having ordinary skill in the art would have been able to modify the cell to have the space velocity of the flush gas fit within the range of 0.1 to 20 1/s. As per MPEP 2144.04 IV A, changes in size/proportion are not patententably distinct.
Ebbesen teaches in the introduction section that “The regions for catalytic formation of coke in SOCs have been treated in great details and it was shown that formation of coke occur at very high CO concentrations only. At realistic CO2/CO concentrations during CO2 electrolysis the equilibrium of the Boudouard reaction is shifted towards CO, and coke will therefore not be formed catalytically during electrolysis.” Therefore, the selection of parameters to prevent coking would have been known to a person having ordinary skill in the art.
In regard to claim 16, Schjodt teaches on page 17 lines 18-30 that the SOEC stacks are susceptible to breaking if individual cells break. This teaches that the stacks of Schjodt comprise a plurality of electrolysis cells arranged in a stack.
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over Schjodt in view of Ebbesen and Jakobsson as applied to claim 16 above, and further in view of WO 2021156457 A1 (henceforth referred to as "Blennow") and "Equilibria in Fuel Cell Gases : II. The C-H-O Ternary Diagrams" By Sasaki and Taraoka in the Journal of The Electrochemical Society, published 03/16/2003 (henceforth referred to as “Sasaki”).
In regard to claim 17, modified Schjodt teaches SOEC electrochemical cells arranged in stacks as described in the rejection to claim 16. The modified cells fail to teach the measurement of temperature, gas composition, local Boudouard temperatures, or local Boudouard margins for locations distributed across a plurality of the cells in the stack.
Blennow teaches a solid oxide electrolysis featuring temperature and gas composition measurements at a plurality of positions such as on page 35 lines 3-25 describing the temperature and CO2 concentration of the feed and exit stream, different locations across cells in the stack.
Sasaki teaches in figure 2 the carbon deposition region based on temperature and gas composition.
It would have been obvious to a person having ordinary skill in the art to measure the temperature across a plurality of cells in the stack as taught by Blennow to monitor and prevent carbon deposition as taught by Sasaki in order to obtain the values needed to calculate the Boudouard temperatures and margins. The Boudouard temperature and margins are calculated values, not measured.
Response to Arguments
Applicant's arguments filed 5/21/2026 have been fully considered but they are not persuasive.
In regard to the 35 US 112 rejections, the rejections are withdrawn due to applicants’ amendments.
In regard to the assertion that the examiner is misapprehending the nature of the claimed subject matter in remarks page 8 paragraph 4 - page 9 paragraph 1, the actual claimed content is what is pertinent. The text of claims 1-14 and 16-17 are drawn to a method of converting carbon dioxide into carbon monoxide, not to a predictive methodology. While claims 15 and 18-19 are drawn to a method of selecting operating conditions, they do not substantively describe predictive methodology beyond straightforward “guess-and-check” to determine operational parameters.
In regard to claim 1 remarks page 9 paragraphs 2 - 4, the claimed coking potential function is a mathematical concept and due to there being no aspect of the invention involving action as a consequence of calculated values, there is no patentable inventive concept. The applicant argues that there is a need to explicitly address temperature, fuel-side space velocity, flush-gas space velocity, current density, and inlet CO concentration. The examiner holds that there is no explicit description limiting any of these parameters in the claims beyond that in aggregate the claimed CP value is less than or equal to -15, which is achieved through the prior art not exhibiting coking and therefore has the combination of parameters that meets the claim.
The applicant argues that the examiner is substituting a general awareness of carbon formation for a particular solution to the problem in remarks page 10 paragraph 1, but the claims do not describe a particular solution beyond that already provided in the prior art.
In regard to whether the claimed subject matter can be characterized as routine optimization in remarks page 10 paragraph 2, this argument does not appear to be in response to any of the examiner’s rejections. Later in the paragraph, the applicant argues that the examiner provides no reasoning why a person of ordinary skills would have identified the claimed governing variables or coordinated them in the claimed manner. The examiner holds that the prior art states that the conditions to prevent coking were readily understood by a person having ordinary skill in the art and while the art does not have the specific equation as claimed, the conditions to prevent coking would result in a device, the use of which would be a method meeting the claims. The claims do not highlight measuring and setting the temperature, fuel-side space velocity, flush-gas space velocity, current density, and inlet CO concentration to any specific values other than the ways that the examiner has addressed with prior art.
In regards to whether Ebbesen undermines the examiner’s argument in remarks page 11 paragraph 1, the art addresses the claims as stated. The applicant argues that their invention stemmed from a deviation from the expectation, but the contents of the claims are nevertheless addressed by the prior art as the claims do not refer to ”distributed operating conditions.”
In regard to “the deficiencies of the rejection” about claim 15 in remarks page 11 paragraph 2, the method as described in the claims does not amount to more than “guess-and-check” and as such is not patentably distinct.
In regard to the subject matter being based upon “the recognition that localized conditions within an operating SOEC may differ…” in remarks page 11 paragraph 3, as explained above, claim 15 does not amount to more than a guess-and-check approach to changing the parameters.
In regard to the applicant arguing that Schjodt, Jakobsson, and Ebbesen fail to teach the distributed thermodynamic analysis or iterative convergence methodology in remarks page 12 paragraph 1, there is no claim to a distributed thermodynamic analysis as you can’t patent an equation and the extent of the iterative methodology in the claims fails to amount to more than guess-and-check.
In regard to the examiner effectively reducing claim 15 to “the abstract proposition that avoiding coking is generally desirable,” in remarks page 12 paragraph 2, as covered in the rejection for the claim, the actual content of the claim is a system that is addressed by prior art and a method of changing parameters with no rationale beyond simply changing values with no specific methodology until a desired condition is met. While there is the measurement of local temperatures, the information collected does not drive any specific change in method.
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 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ASHLEY SABATOSE whose telephone number is (571)272-9893. The examiner can normally be reached 7:30-5:30 M-Th.
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/A.C.S./Examiner, Art Unit 1791
/Nikki H. Dees/Supervisory Patent Examiner, Art Unit 1791
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