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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 04/06/2026 has been entered.
Election/Restrictions
Newly submitted claim 59 lacks unity of invention because it is directed to an invention that requires the special technical feature of the methane input, a CO2 removal stage, and a liquefication stage but does not make a contribution over the prior art as stated in the 03/19/2025 Office Action.
Since applicant has received an action on the merits for the originally presented invention, this invention has been constructively elected by original presentation for prosecution on the merits. Accordingly, claims 59-61 are withdrawn from consideration as being directed to a non-elected invention. See 37 CFR 1.142(b) and MPEP § 821.03.
To preserve a right to petition, the reply to this action must distinctly and specifically point out supposed errors in the restriction requirement. Otherwise, the election shall be treated as a final election without traverse. Traversal must be timely. Failure to timely traverse the requirement will result in the loss of right to petition under 37 CFR 1.144. If claims are subsequently added, applicant must indicate which of the subsequently added claims are readable upon the elected invention.
Should applicant traverse on the ground that the inventions are not patentably distinct, applicant should submit evidence or identify such evidence now of record showing the inventions to be obvious variants or clearly admit on the record that this is the case. In either instance, if the examiner finds one of the inventions unpatentable over the prior art, the evidence or admission may be used in a rejection under 35 U.S.C. 103 or pre-AIA 35 U.S.C. 103(a) of the other invention.
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 23, 57 and 58 are rejected under 35 U.S.C. 103 as being unpatentable over Krylowicz et al. (PL197595B1) in view of Leonard et al. (US20060213370).
Regarding Claim 23, Krylowicz teaches the following:
A biogas purification system, biogas, carbon dioxide processing system and methane processing system as well as the gas mixer and technological tanks (a biogas processing plant)(para 17).
The biogas separation system is in the form of a two chamber saturator (CO2 removal stage) with an inlet chamber A (methane input to the processing plant) which received purified biogas from the biogas tank 7 (for receiving methane-enriched gas from an external source of the methane-enriched gas) and is filled with a liquid absorbing only CO2 from the gas mixture and a methane gas pipeline at the outlet (para 17)
Note: the source is external to what is being interpreted as the biogas processing plant which is the section of the plant that begins after biogas tank 7 (see Fig. 3, below).
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The methane gas processing system comprises the methane gas pipeline exiting the saturator to a methane condenser further connected to a liquified methane tank (liquefaction stage)(para 17)
Krylowicz does not teach the biogas processing plant to be mobile.
Leonard teaches a mobile biogas processing system (Abstract). Leonard further teaches the processing system to be mounted to the trailer of a truck (mobile biogas processing plant)(para 58 and Fig. 9A, below).
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It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to make the device of Krylowicz as a mobile system as taught by Leonard. One would have been motivated to make this modification as it is beneficial to be able to drop the system off at a site for a period of time and then retrieved later (para 58).
Regarding Claim 57, Krylowicz in view of Leonard teach all of the limitations of Claim 23 (see above). Further, the limitation of the methane enriched gas having a ratio of methane to CO2 of 85:15 or higher is directed to the material worked upon by the apparatus, all the structural limitations of the claim has been disclosed by Krylowicz in view of Leonard and the apparatus of Krylowicz in view of Leonard is capable of working on methane enriched gas having a ratio of methane to CO2 of 85:15 or higher. As such, it is deemed that the claimed apparatus is not differentiated from the apparatus of Krylowicz in view of Leonard (see MPEP §2115).
Regarding Claim 58, , Krylowicz in view of Leonard teach all of the limitations of Claim 23 (see above). Further, the limitation of the CO2-enriched gas being less than or equal to .1% methane is directed to the material worked upon by the apparatus, all the structural limitations of the claim has been disclosed by Krylowicz in view of Leonard and the apparatus of Krylowicz in view of Leonard is capable of working on CO2-enriched gas being less than or equal to .1% methane. As such, it is deemed that the claimed apparatus is not differentiated from the apparatus of Krylowicz in view of Leonard (see MPEP §2115).
Claims 23-28, 32, 34, 60, and 61 are rejected under 35 U.S.C. 103 as being unpatentable over Park et al. (KR101027809B1) in view of Leonard et al. (US20060213370).
Regarding Claim 23, Park teaches the following:
A liquified biomethane production device (para 1)(a biogas processing plant).
Biogas generated from an anaerobic digestion tank is supplied through a pretreatment process 110 and sent to the cold box (120) which liquifies the biogas and separates carbon dioxide contained in the biogas (para 109 and 110)(a methane input (for receiving methane-enriched gas from an external source of the methane-enriched gas) to the processing plant and one or more CO2 removal stages configured to remove CO2 from the gas, and a liquefaction stage configured to generate liquid methane from the gas)
Park does not teach the biogas processing plant to be mobile.
Leonard teaches a mobile biogas processing system (Abstract). Leonard further teaches the processing system to be mounted to the trailer of a truck (mobile biogas processing plant)(para 58 and Fig. 9A, below).
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It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to make the device of Park as a mobile system as taught by Leonard. One would have been motivated to make this modification as it is beneficial to be able to drop the system off at a site for a period of time and then retrieved later (para 58).
Regarding Claim 24, Park in view of Leonard teaches all of the limitations of Claim 23 (see above). Park further teaches carbon dioxide (CO2 enriched gas) is introduced into the pre-cooling heat exchanger 121 (para 116). This means the pre-cooling heat exchanger must have a CO2 input to the processing plant which receives CO2 enriched gas. Further, the cold box (120) which liquifies the biogas and separates carbon dioxide contained in the biogas (para 109 and 110) is what is being considered as the CO2 removal stage in which the CO2 input is connected to by way of the precooling heat exchanger. The CO2 removal stages configured to generate liquid or solid CO2 from the CO2 enriched gas is an intended use of the device. A recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim (see MPEP 2114). The biogas plant as taught by Park would be capable of generating liquid or solid CO2 were it to be supplied to the CO2 removal stage and therefore meets the claim.
Regarding Claim 25, Park in view of Leonard teaches all of the limitations of Claim 23 (see above). Park further teaches the cold box receives the biogas liquifies it and simultaneously separates the carbon dioxide (para 110)(one of the CO2 removal stages and the liquefaction stage are a single combined stage).
Regarding Claim 26, Park in view of Leonard teaches all of the limitations of Claim 23 (see above). Park further teaches during the separation process, carbon dioxide is solidified and then gasified and discharged to the outside of the second heat exchanger (para 113-114) and is then supplied to the pre-cooling heat exchanger, which is part of the CO2 removal stage, in which the biogas flows through after the pre-treatment process (para 116)(one of the CO2 removal stages is configured to operate using liquid CO2 extracted from the methane-enriched gas).
Regarding Claim 27, Park in view of Leonard teaches all of the limitations of Claim 23 (see above). Park further teaches, as above, the CO2 is solidified, gasified, and supplied to the pre-cooling exchanger, which is also part of the liquefaction stage (para 116)(the liquefaction stage is configured to operate using liquid CO2 extracted from the methane-enriched biogas).
Regarding Claim 28, Park in view of Leonard teaches all of the limitations of Claim 27 (see above). Park further teaches a pre-cooling heat exchanger and at least two heat exchangers coupled to that (para 110)(a heat exchanger for cooling input gas).
Regarding Claim 32, Park in view of Leonard teaches all of the limitations of Claim 23 (see above). Park does not teach the biogas plant to comprise a vehicle and is transportable to a remote site.
Leonard teaches a mobile biogas processing system (Abstract). Leonard further teaches the processing system to be mounted to the trailer of a truck (vehicle)(para 58 and Fig. 9A, below).
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It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to make the device of Park as mobile system with a transport via a truck as taught by Leonard. One would have been motivated to make this modification as it is beneficial to be able to drop the system off at a site for a period of time and then retrieved later (para 58).
Regarding Claim 34, Park in view of Leonard teaches all of the limitations of Claim 23 (see above). Park further teaches the liquified methane is stored in storage tank 141 (para 145)(a liquid methane storage unit coupled to an output of the liquefaction stage). The storage tank would be removable and replaceable with a replacement unit in some capacity as it would have been installed to collect the liquified methane initially.
Regarding Claim 60, Park in view of Leonard teaches all of the limitations of Claim 23 (see above). Park further teaches the liquefying of biogas in the heat exchangers, and the carbon dioxide separation process can be done alternately (one of the CO2 removal stages is separate from the liquefaction stage)(para 131).
Regarding Claim 61, Park in view of Leonard teaches all of the limitations of Claim 60 (see above). Park further teaches gas pipes connected to the first and second heat exchangers and carbon dioxide separation device (para 55).
Claim 29 is rejected under 35 U.S.C. 103 as being unpatentable over Park et al. (KR101027809B1) in view of Leonard et al. (US20060213370) and further in view of Fieler et al. (WO2008091316A1).
Park in view of Leonard teaches all of the limitations of Claim 23 (above). Park in view of Leonard does not teach the liquefication stage to comprise one or more of a Joule-Thompson unit or cryocooler.
Fieler teaches a tower for separation of a fluid stream containing at least methane and carbon dioxide (Abstract). Fieler further teaches the fluid stream is typically chilled and moved through an expansion device such as a Joule-Thompson valve which serves as an expander to obtain subcooling and partial liquification of the gas (para 40).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a Joule-Thompson valve as taught by Fieler. One would have been motivated to make this modification as Feiler teaches it to be an effective method of liquefying the feed gas. Further, a selection of known item based on its suitability for its intended use has been deemed prima facie obvious. See MPEP 2144.07.
Claim 31 is rejected under 35 U.S.C. 103 as being unpatentable over Park et al. (KR101027809B1) in view of Leonard et al. (US20060213370) and further in view of Heffernan et al. (EP3339253A1).
Park in view of Leonard teaches all of the limitations of Claim 23 (see above). Park further teaches the device for liquefying methane contained in biogas generated from an anaerobic digestion tank (anaerobic digester). Park in view of Leonard does not teach the methane input to be coupled to an anaerobic digester comprising at least one semipermeable membranes that is selectively permeable between CO2 and methane.
Heffernan teaches recovering carbon dioxide from biogas produced in an anaerobic digester (para 53). Heffernan further teaches a known technique, which is using a gas-selective membrane, which is either more permeable to carbon dioxide or more permeable to methane (an anaerobic digester comprising at least one semipermeable membrane that selectively permeable between CO2 and methane)(para 53).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Park in view of Leonard and to have the anaerobic digestion tank to include a selectively permeable membrane as taught by Heffernan. One would have been motivated to make this modification as it, as Heffernan stated, it is a known technique for recovering either carbon dioxide or methane from an anaerobic digester (para 53) and it would have yielded an effective way of collecting a gas either richer in carbon dioxide or methane depending on the needs of the system.
Claim 33 is rejected under 35 U.S.C. 103 as being unpatentable over Park et al. (KR101027809B1) in view of Leonard et al. (US20060213370) and further in view of Golo (FR2971332A1).
Park in view of Leonard teaches all of the limitations of Claim 23 (see above). Park in view of Leonard does not teach a liquid nitrogen storage that is removeable and replaceable with a replacement unit.
Golo teaches the apparatus to comprise a storage for the nitrogen-rich liquid (sacrificial cooling liquid) connected to the means for sending the liquid into an exchanger (lines 80-84). As the system must have been built and put together including the storage unit, the storage unit is therefore, in some capacity, removable or replaceable with a different unit.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Park in view of Leonard with the liquid nitrogen storage unit as taught by Golo. One would have been motivated to make this modification as it is an effective way of providing liquid nitrogen to the system as needed that one of ordinary skill would choose.
Response to Arguments
Applicant's arguments filed 03/05/2026 have been fully considered but they are not persuasive.
Regarding applicant’s arguments on page 6 and 7 that Krylowicz and Park does not teach a mobile biogas processing plant, the teachings of prior art reference Leonard have been incorporated to address the “mobile” limitation.
Regarding applicant’s arguments on page 7 that Krylowicz does not teach the methane input receiving methane enriched gas from an external source, the source is external to what is being interpreted as the biogas processing plant which is the section of the plant that begins after biogas tank.
Regarding applicant’s arguments on page 9 that Park fails to teach a CO2 input to the processing plant, Park teaches carbon dioxide (CO2 enriched gas) is introduced into the pre-cooling heat exchanger 121 (para 116). This requires an input into the processing plant (as the pre-cooling heat exchanger is part of the processing plant). Further, the cold box (120) which liquifies the biogas and separates carbon dioxide contained in the biogas (para 109 and 110) is what is being considered as the CO2 removal stage in which the CO2 input is connected to by way of the precooling heat exchanger.
Regarding applicant’s arguments on page 10 that Park does not teach the liquefication stage to operate using liquid or solid CO2 extracted from the methane gas, Park teaches the CO2 is solidified, gasified, and supplied to the pre-cooling exchanger (which the examiner is considering as part of the liquefaction stage)(para 116).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JONATHAN E LEPAGE whose telephone number is (571)270-3971. The examiner can normally be reached 8:30-5:30 ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Michael Marcheschi can be reached at 571-272-1374. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/J.E.L./Examiner, Art Unit 1796
/MICHAEL A MARCHESCHI/Supervisory Patent Examiner, Art Unit 1799
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