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 .
Response to Amendments
This is a non-final office action in response to applicant's arguments and remarks filed on 08/28/2025.
Status of Rejections
The rejection of claims 7-11 are withdrawn in view of the Applicant’s amendments.
The heading for the rejections under 35 USC 103 has been corrected and all the rejections are maintained.
Claims 1-20 are pending and under consideration for this Office Action.
Claim Objection
Claim 8 is objected to because of the following informalities:
The claim claims “…wherein at least p of the first condensate and the further condensate is combined…”.
Appropriate correction is required.
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.
Claim(s) 1-5 and 9-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kirk et al (US 20020100681 A1) in view of Price et al (US 20200099061 A1), Yachi et al (US 20190260056 A1), Jung et al (US 20170073821 A1), and Ring (“Chapter 8 Reactor-Separator-Recycle Networks”, 2016, pages CD-8-(1-26)).
Claim 1: Kirk discloses a method for producing a gas product containing oxygen (see e.g. [0001]), the method comprising:
subjecting a feedstock containing water to electrolysis to obtain a raw anode gas, which is rich in oxygen (see e.g. [0001], [0003], [0081]), and a raw cathode gas, which is rich in hydrogen (see e.g. [0001], [0003], [0081]).
Kirk does not explicitly teach that that the raw anode gas also contains hydrogen and the raw cathode gas also contains oxygen. Kirk discloses minimizing and preventing intermixing the product gases (see e.g. [0081]). However, preventing complete crossover over the product gases is hard to achieve (see e.g. [0003]-[0004] of Price). This is due to “crossover phenomenon” caused by high pressure within the cell (see e.g. [0005] of Yachi). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention that the raw anode gas would contain some amount of hydrogen and the raw cathode gases in Kirk would contain some amount of oxygen due to crossover phenomenon.
Kirk does not explicitly teach at least partially subjecting the raw anode gas to a catalytic conversion of hydrogen to water to obtain an intermediate mixture with depleted hydrogen content. Both Price and Yachi teach that the presence of hydrogen in the oxygen stream is dangerous due to the risk of explosion (see e.g. [0003] of Price; [0005] of Yachi). Jung teaches a system that removes hydrogen from a gas stream via catalytic conversion to water (see e.g. [0009]) to obtain an intermediate mixture with depleted hydrogen content (see e.g. Fig 5) in order to reduce the risks of explosion caused by the presence of hydrogen (see e.g. [0003]-[0004]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk to include the step of subjecting the raw anode gas to a catalytic conversion of hydrogen to water to obtain an intermediate mixture with depleted hydrogen content to remove any hydrogen in the raw anode gas steam from crossover phenomenon and reduce the risk of explosion. Furthermore, the product stream of the catalytic conversion would be hydrogen depleted and contain the oxygen gas product.
Kirk in view of Price, Yachi, and Jung does not explicitly teach that a first part of the intermediate mixture is returned to the raw anode gas at a return point which is downstream of the electrolysis and upstream of the catalytic conversion to reduce the hydrogen concentration of the raw anode gas introduced into the catalytic conversion, and that the gas product containing oxygen is formed using at least a second part of the intermediate mixture. Ring teaches “The feed to a reactor section of a chemical process almost always is a combined feed consisting of a fresh feed mixed with one or more recycle streams… Thus, almost every chemical process that involves a chemical reaction section also involves one or more separation sections in addition to one or more recycle streams” (see e.g. page CD-8-2) to improve process conversion (see e.g. page CD-8-3, paragraph starting with “In many”). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk so that the product stream leaving the catalytic conversion part of the method is separated into a product stream containing the desired oxygen and a recycle stream containing unreacted reactants is returned to the raw anode gas downstream of the electrolysis and upstream of the catalytic conversion.
The mixing of the raw anode gas with the first part of the immediate mixture would reduce the hydrogen concentration of the raw anode gas due to dilution from the hydrogen depleted first part of the immediate mixture. Furthermore, splitting the intermediate mixture so that a first part is recycled would create a second part (the part not recycled) containing oxygen gas product.
Claim 2: Kirk in view of Price, Yachi, Jung, and Ring teaches that the oxygen stream is at least partially subjected to condensation to obtain an intermediate mixture fraction with depleted water content, and a condensate, which is rich in water (see e.g. #108 on Fig 2 and [0092] of Kirk).
Kirk does not explicitly teach that oxygen stream is specifically the intermediate mixture. However, Jung teaches that the catalytic conversion step forms water (see e.g. Fig 5). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk to use the intermediate mixture, instead of the raw anode gas, so that the condensation step only needs to be done once.
Claim 3: Kirk in view of Price, Yachi, Jung, and Ring does not explicitly teach that at least a part of the intermediate mixture fraction is subjected to drying to obtain the second part of the intermediate mixture which forms gas product, which contains oxygen, and a residual gas with depleted oxygen content and enriched water content. However, Kirk teaches treating the gas stream from the electrolyzer with dryers to remove liquid from the gases (see e.g. #116 on Fig 2 and [0094] of Kirk). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk in view of Price, Yachi, Jung, and Ring by positioning the dryers after the catalytic conversion step to remove any liquids left or formed in the gaseous product streams.
Claim 4: Kirk in view of Price, Yachi, Jung, and Ring teaches that the first part of the intermediate mixture, which is returned to the raw anode gas, is formed using at least a quantitative proportion of the intermediate mixture (based on hydrogen converted, see e.g. [0047]).
Claim 4: Kirk does not explicitly teach that the first part of the intermediate mixture is returned to the raw anode gas or the anode-side feedstock in an amount which is measured such that a hydrogen concentration in the raw anode gas downstream of the return is at most 2%.
Price teaches that hydrogen should be kept at 2% or less “to ensure that a flammable mixture does not exist in the system and such a high initial level will lead to a reduced operating lifetime of the system due to membrane thinning increasing crossover with time” (see e.g. [0181]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk so that the intermediate mixture leaving the catalytic conversion step has a hydrogen concentration of 2% or less.
Claim 9: Kirk does not explicitly teach that downstream of the electrolysis and/or in the catalytic conversion, one or more process parameters, selected from a hydrogen concentration and a gas temperature, a difference between two gas temperatures, and a gas pressure, are detected, and wherein the first part of the intermediate mixture
i) is returned to the raw anode gas when the one or more process parameters are above a predetermined threshold value; or
ii) is returned in an amount controlled continuously using the detected process parameters.
Price teaches monitoring hydrogen concentration (see e.g. [0182] and that “[t]ypically, a limit of 2% hydrogen in oxygen is used to ensure that a flammable mixture does not exist in the system and such a high initial level will lead to a reduced operating lifetime of the system due to membrane thinning increasing crossover with time” (see e.g. [0181]). Ring teaches “The feed to a reactor section of a chemical process almost always is a combined feed consisting of a fresh feed mixed with one or more recycle streams… Thus, almost every chemical process that involves a chemical reaction section also involves one or more separation sections in addition to one or more recycle streams” (see e.g. page CD-8-2) to improve process conversion (see e.g. page CD-8-3, paragraph starting with “In many”). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk so that downstream the cell and catalytic conversion, a hydrogen concentration is detected, and wherein the first part of the first mixture is returned to the raw anode gas when the one or more process parameters are above 2% hydrogen to further decrease the amount of hydrogen in the oxygen stream to ensure that a flammable mixture does not exist in the system.
Claim 10: Price teaches that a hydrogen concentration of 5-95% is a significant safety hazard (see e.g. [0003]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk in view of Price, Yachi, and Jung that the raw anode gas is discharged from the process when the hydrogen concentration exceeds 5% to remove the safety hazard of high hydrogen concentrations in the oxygen stream,
Claim 11: Kirk in view of Price, Yachi, and Jung teaches that the electrolysis is operated at a pressure level at which the drying is also operated (see e.g. [0094] of Kirk).
Claim 12: Kirk in view of Price, Yachi, and Jung teaches heating the raw anode gas (electrolyzed water) in a heat exchanger against the intermediate mixture (see e.g. [0048] of Jung).
Claim 13: Kirk discloses a plant for producing a gas product containing oxygen with an electrolysis unit (see e.g. [0001] and Fig 2), configured to subject a feedstock containing water to electrolysis to obtain a raw anode gas, which is rich in oxygen (see e.g. [0001], [0003], [0081]), and a raw cathode gas, which is rich in hydrogen (see e.g. [0001], [0003], [0081]).
Kirk does not explicitly teach that that the raw anode gas also contains hydrogen and the raw cathode gas also contains oxygen. Kirk discloses minimizing and preventing intermixing the product gases (see e.g. [0081]). However, absolute crossover over the product gases is hard to achieve (see e.g. [0003] of Price). This is due to “crossover phenomenon” caused by high pressure within the cell (see e.g. [0005] of Yachi). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention that the raw anode gas would contain some amount of hydrogen and the raw cathode gases in Kirk would contain some amount of oxygen due to crossover phenomenon.
Kirk does not explicitly teach a catalytic conversion unit configured, using at least a part of the raw anode gas, to subject to a catalytic conversion of hydrogen to water to obtain an intermediate mixture with depleted hydrogen content. Both Price and Yachi teach that the presence of hydrogen in the oxygen stream is dangerous due to the risk of explosion (see e.g. [0003] of Price; [0005] of Yachi). Jung teaches a system that removes hydrogen from a gas stream via catalytic conversion (see e.g. [0009] to water to obtain an intermediate mixture with depleted hydrogen content (see e.g. Fig 5) in order to reduce the risks of explosion caused by the presence of hydrogen (see e.g. [0003]-[0004]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the system of Kirk to include the catalytic conversion unit configured, using at least a part of the raw anode gas, to subject to a catalytic conversion of hydrogen to water to obtain an intermediate mixture with depleted hydrogen content to remove any hydrogen in the raw anode gas steam from crossover phenomenon and reduce the risk of explosion.
Kirk in view of Price, Yachi, and Jung does not explicitly teach the system is configured to return a first part of the intermediate mixture to the raw anode gas downstream of the electrolysis and upstream of the catalytic conversion, and to form the gas product containing oxygen using a second part of the intermediate mixture. Ring teaches “The feed to a reactor section of a chemical process almost always is a combined feed consisting of a fresh feed mixed with one or more recycle streams… Thus, almost every chemical process that involves a chemical reaction section also involves one or more separation sections in addition to one or more recycle streams” (see e.g. page CD-8-2) to improve process conversion (see e.g. page CD-8-3, paragraph starting with “In many”). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the system of Kirk so that the product stream leaving the catalytic conversion part of the method is separated into a product stream containing the desired oxygen and a recycle stream containing unreacted reactants is returned to the raw anode gas downstream of the electrolysis and upstream of the catalytic conversion.
Claim 14: Kirk in view of Price, Yachi, Jung, and Ring teaches means to at least partially subject the intermediate mixture is to condensation to obtain an intermediate mixture fraction with depleted water content, and a condensate, which is rich in water (see e.g. #108 on Fig 2 and [0092] of Kirk).
Claim 16: Kirk does not explicitly teach that the first part of the intermediate mixture is returned to the raw anode gas in an amount which is measured such that a hydrogen concentration in the raw anode gas downstream of the return is at most 1%. Price teaches that hydrogen should be kept at 2% or less “to ensure that a flammable mixture does not exist in the system and such a high initial level will lead to a reduced operating lifetime of the system due to membrane thinning increasing crossover with time” (see e.g. [0181]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk so that the intermediate mixture leaving the catalytic conversion step has a hydrogen concentration of 2% or less.
Claim 17: Kirk does not explicitly teach that the first part of the intermediate mixture is returned to the raw anode gas in an amount which is measured such that a hydrogen concentration in the raw anode gas downstream of the return is at most 0.5%. Price teaches that hydrogen should be kept at 2% or less “to ensure that a flammable mixture does not exist in the system and such a high initial level will lead to a reduced operating lifetime of the system due to membrane thinning increasing crossover with time” (see e.g. [0181]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk so that the intermediate mixture leaving the catalytic conversion step has a hydrogen concentration of 2% or less.
Claim 18: Kirk does not explicitly teach that the raw anode gas introduced into the catalytic conversion contains 0.1% to 2% hydrogen. Price teaches that hydrogen should be kept at 2% or less “to ensure that a flammable mixture does not exist in the system and such a high initial level will lead to a reduced operating lifetime of the system due to membrane thinning increasing crossover with time” (see e.g. [0181]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk so that the raw anode gas has a hydrogen concentration of 2% or less.
Claim 19: Kirk in view of Price, Yachi, and Jung teaches that pressure of the system should be regulated and maintained (see e.g. [0094] of Kirk). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to maintain system pressure on the part of the intermediate mixture returned to the raw anode gas to match that of the rest of the system. Furthermore, a person having ordinary skill in the art before the effective filing date of the instant invention would understand compression as a means of increasing a gas’s pressure.
Claim 20: Kirk in view of Price, Yachi, and Jung teaches that pressure of the system should be regulated and maintained (see e.g. [0094] of Kirk). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to maintain system pressure on the part of the intermediate mixture returned to the raw anode gas to match that of the rest of the system. Furthermore, a person having ordinary skill in the art before the effective filing date of the instant invention would understand compression as a means of increasing a gas’s pressure.
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kirk in view of Price, Yachi, Jung, and Ring as applied to claim 3 above, and in further view of Ballantine et al (US 20210156038 A1).
Claim 6: Kirk does not explicitly teach that the drying comprises a temperature swing adsorption (TSA). Kirk teaches using a bed to dry the gas stream (see e.g. [0094]). Ballantine teaches that TSA is a suitable alternative means of drying (see e.g. [0033]) so for a water electrolysis system (see e.g. abstract). KSR rationale B states that “[s]imple substitution of one known element for another to obtain predictable results” is obvious medication and KSR rationale E states that it is obvious to choose “from a finite number of identified, predictable solutions, with a reasonable expectation of success”. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk by substituting the drying means in Kirk with the TSA taught in Ballantine.
Claim(s) 7 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kirk in view of Price, Yachi, Jung, and Ring as applied to claim 3 above, and in further view of Braun et al (US 9631284 B2).
Claim 7: Kirk does not explicitly teach that the intermediate mixture fraction is subjected to a compression upstream of the drying and is then subjected to a further condensation, to obtain a further intermediate mixture fraction and a further condensate. Braun teaches that drying a gas stream can include a compression step wherein condensable components are separated from the gas (“compressing an air stream”), condensed (“condensing comprises cooling”), and dried (“heating the pressurized air stream”, see e.g. col 11, lines 1-27). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk by subjecting the intermediate mixture fraction to a compression upstream of the drying and, to obtain a further intermediate mixture fraction and a further condensate to remove the condensable components before drying.
Claim 8: Kirk in view of Brain does not explicitly teach that the intermediate that at least one of the first condensate and the further condensate is combined together with the feedstock is partially or completely returned to the electrolysis. However, as explained above, Ring teaches “The feed to a reactor section of a chemical process almost always is a combined feed consisting of a fresh feed mixed with one or more recycle streams… Thus, almost every chemical process that involves a chemical reaction section also involves one or more separation sections in addition to one or more recycle streams” (see e.g. page CD-8-2) to improve process conversion (see e.g. page CD-8-3, paragraph starting with “In many”). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Kirk in view of Brain so that at least one of the condensates is combined together with the feedstock is partially or completely returned to the electrolysis.
Response to Arguments
This is a response to the arguments filed on 08/28/2025.
The examiner apologizes for the issue with Jung. That has been corrected in this Office Action.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDER W KEELING whose telephone number is (571)272-9961. The examiner can normally be reached 7:30 AM - 4:00 PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Luan Van can be reached at 571-272-8521. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ALEXANDER W KEELING/Primary Examiner, Art Unit 1795