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 .
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 1-13 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-13 of U.S. Patent No.11,220,470. Although the claims at issue are not identical, they are not patentably distinct from each other because both sets of claims includes steps of recovering methane and carbon dioxide from a biogas. There are minor differences between the present claimed set and the Patent claimed set and such differences would have been obvious to one of skill in the art.
Claims 1-13 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-30 of U.S. Patent No.10,968,151. Although the claims at issue are not identical, they are not patentably distinct from each other because both sets of claims includes steps of recovering methane and carbon dioxide from a biogas. There are minor differences between the present claimed set and the Patent claimed set and such differences would have been obvious to one of skill in the art.
Claims 1-9 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-2 of U.S. Patent No.11,708,313. Although the claims at issue are not identical, they are not patentably distinct from each other because both sets of claims includes steps of recovering methane and carbon dioxide from a biogas. There are minor differences between the present claimed set and the Patent claimed set and such differences would have been obvious to one of skill in the art.
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. Claims 1, 2, 11 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over CN 101691320 A (“CN ’320”) in view of Sethna et al. (US 2011/0185896 A1).
Regarding claim 1, CN ’320 teaches a process for recovering methane and carbon dioxide from landfill gas/biogas. The landfill gas is subjected to pretreatment including desulfurization, compression and cooling, followed by adsorption separation to produce a high-purity methane product and a CO₂ rich desorption gas (CN ’320, ¶¶[0012], [0019]–[0023], [0040], [0044]–[0045], [0060]–[0063]; Figs. 2–4). The CO₂-rich gas is compressed, cooled and dried, subjected to condensation/liquefaction, and introduced into a flash device to recover a liquid CO₂ product of approximately 99.9% purity; the flash vapor/waste gas is recycled through the gas outlet of the flash device to the upstream raw-gas compression stage, whereby unrecovered gaseous CO₂ is returned through the process for further recovery (CN ’320, ¶¶[0040], [0045], [0060]–[0063]; Fig. 3). CN ’320 does not expressly disclose separating condensed liquid water and removing trace contaminants with the specificity recited.
Sethna teaches processing landfill/digester biogas by cooling/condensation and compression, including removal of condensate, followed by adsorption treatment (Sethna, ¶¶[0055]–[0059], [0094]–[0097]; Fig. 2), and teaches adsorbents/guard beds for removing water, H₂S and other sulfur compounds, NMOCs/VOCs, halogenated compounds, and siloxanes (Sethna, ¶¶[0055]–[0062]).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified CN’320 process to employ Sethna's known water and trace-contaminant removal in CN ’320's biogas pretreatment to remove condensable water and undesirable contaminants before downstream adsorption and CO₂ liquefaction, thereby protecting downstream processing equipment and improving product purity.
CN ’320/Sethna do not expressly state that the facility monitors “material and energy inputs and outputs.” However, it would have been obvious to monitor the material streams and energy inputs/outputs of the disclosed industrial gas-processing facility in order to operate and control its compressors, coolers, dryers, adsorption units and liquefaction equipment and to determine process performance, material balance and energy consumption. CN ’320 itself employs automated PLC control of its PSA system (CN ’320, claim 7; ¶¶[0057]–[0059]), further evidencing conventional monitoring/control of the disclosed processing facility.
Regarding claim 2, Sethna teaches drying the gas by cooling/condensation and adsorption before further purification (Sethna, ¶¶[0055]–[0062], [0094]–[0097]; Fig. 2). Since claim 2 recites the additional steps as alternatives (“any of”), the disclosed drying step satisfies at least one of the claimed alternatives.
Regarding claim 11, Although the references do not expressly disclose a residual halogenated-hydrocarbon concentration below 0.1 ppmv, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of CN ’320 to operate the expressly taught contaminant-removal treatment to reduce the known undesirable halogenated hydrocarbons to a suitably low level, including below 0.1 ppmv, because further removal of such contaminants predictably increases the purity and suitability of the resulting biomethane product. Determining the extent of removal necessary to obtain the desired high-purity biomethane would have constituted routine optimization of an expressly taught purification step. Regarding claim 12, Sethna likewise expressly teaches removal of residual siloxanes from landfill biogas using the guard-bed treatment (Sethna, ¶¶[0055]–[0062]). Although Sethna does not expressly disclose a residual siloxane concentration below 0.01 mg Si/m³, it would have been obvious to one of ordinary skill in the art to optimize the expressly taught siloxane-removal treatment to reduce residual siloxanes to a suitably low level, including below 0.01 mg Si/m³, because minimizing residual siloxanes predictably provides a cleaner, higher-purity biomethane product and reduces the undesirable effects for which Sethna removes siloxanes. The claimed concentration therefore represents optimization of the degree of an expressly taught contaminant-removal operation.
Claims 8 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over references as applied to claim 1 above, and further in view of Yousef et al., “New approach for biogas purification using cryogenic separation and distillation process for CO2 capture” Energy 156 (2018), pp 328–351.
Regarding claim 8, CN ’320 does not expressly disclose an overall methane recovery efficiency greater than 98%.
Yousef teaches cryogenic biogas upgrading with less than 1% methane loss while producing high-purity biomethane and liquid CO₂ (Yousef: pp. 328–351, Abstract and discussion of cryogenic separation/methane loss).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to operate CN ’320's methane/CO₂ recovery process according to the known high-methane-recovery conditions taught by Yousef in order to minimize loss of the valuable methane product and maximize biomethane recovery.
Regarding claim 9, CN ’320 teaches production of a high-purity methane product, including methane purities exceeding 99% (CN ’320, ¶¶[0044]–[0045] and Examples). Although CN ’320 does not expressly report a gross heating value greater than 1,000 Btu/SCF, it would have been obvious to provide such a heating value by increasing methane purity/removing noncombustible CO₂ and other diluents to obtain Yousef’s high-purity biomethane, because such removal predictably increases the heating value per unit volume. Selection of a methane purity sufficient to provide a desired fuel-gas heating value would have been routine optimization of CN ’320's expressly disclosed high-purity biomethane product.
Claims 3 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over CN ’320 in view of Sethna, as applied to claim 2 above, and further in view of Prince et al. (US 2019/0001263 A1).
Regarding claim 3, Prince teaches a landfill-biogas purification plant employing drying, desulfurization, VOC removal, CO₂ purification and cryogenic separation (Prince, ¶¶[0047]–[0054], [0073]–[0080]; Figs. 1–2) and teaches using an available N₂-rich stream from cryogenic separation for regeneration of contaminant-loaded adsorbent. It would have been obvious to use the separated nitrogen stream to regenerate contaminant-laden adsorbent in the modified CN/Sethna process, thereby beneficially using an available inert process stream while regenerating the adsorbent for continued purification.
Regarding claim 4, Prince further teaches treating/oxidizing the contaminant-containing gas resulting from adsorbent regeneration, including embodiments employing the N₂-rich cryogenic stream in association with the regeneration operation (Prince, discussion of PSA/PTSA regeneration and oxidation of regeneration gas). It would have been obvious to direct the resulting contaminant-laden nitrogen-containing regeneration stream to a thermal oxidizer or flare in order to thermally destroy the concentrated contaminants before discharge.
Claims 5, 6, 10 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over CN ’320 in view of Sethna, as applied to claim 2 above, and further in view of FR 2,928,720 A1 (“FR ’720”). Regarding claim 5, FR ’720 teaches cryogenic separation of a CO₂-containing hydrocarbon gas to produce a CO₂-rich liquid stream and expressly teaches pressurizing the recovered CO₂ for injection into an underground reservoir for sequestration (FR ’720, p. 2, discussion of high-pressure reinjection/sequestration; pp. 8–10 and Figs. 1, 3, CO₂-rich liquid stream 30 and pump P1). It would have been obvious to inject CN ’320's recovered liquid CO₂ into an underground geologic reservoir as taught by FR ’720 because sequestration provides a known beneficial disposition of the recovered CO₂ rather than releasing it to the atmosphere. Regarding claim 6, the references do not expressly disclose monitoring the reservoir for verification of extended or permanent CO₂ storage. However, once the recovered CO₂ is deliberately injected into an underground reservoir for permanent sequestration as taught by FR ’720, it would have been obvious to monitor the reservoir to verify that the injected CO₂ remains stored and thereby confirm that the sequestration operation achieves its intended purpose. Such verification is a predictable monitoring step attendant to permanent underground storage.
Regarding claim 10, although CN ’320 and FR ’720 do not expressly disclose that the biomethane product has a carbon intensity of less than 25 gCO₂e/MJ, It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of CN ’320 to operate and optimize the disclosed biogas purification, methane-recovery, CO₂-recovery, and CO₂-sequestration processes so as to minimize the greenhouse-gas emissions attributable to the useful biomethane product, including minimizing methane losses and recovering/sequestering separated CO₂ rather than releasing those greenhouse gases to the atmosphere. Optimization toward lower carbon intensity would have predictably increased the environmental benefit of the biomethane product, and the claimed value of less than 25 gCO₂e/MJ represents a degree of the desired reduction in greenhouse-gas emissions obtainable by optimization of the known process. Regarding claim 13, CN ’320 recovers methane and carbon dioxide from landfill gas, including recovery of carbon dioxide as a concentrated liquid product rather than simply discharging the separated carbon dioxide (CN ’320, ¶¶[0040], [0044]–[0045], [0060]–[0064]). FR ’720 further teaches injecting recovered carbon dioxide into an underground reservoir for sequestration, thereby preventing the sequestered carbon dioxide from being released to the atmosphere (FR ’720, pp. 2, 8–10; Figs. 1 and 3). Although the references do not expressly disclose generating credits due to the resulting reduction in greenhouse gases, It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of CN ‘320 to generate or obtain available greenhouse-gas/carbon credits attributable to the reduction or sequestration of greenhouse-gas emissions resulting from the disclosed process, because such credits provide a known economic benefit associated with reducing or permanently storing greenhouse gases. Generation of the credit does not alter the underlying methane/CO₂ recovery and sequestration process but represents obtaining the known economic benefit associated with the greenhouse-gas reduction produced by that process.
Allowable Subject Matter
Claim 7 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TAM M NGUYEN whose telephone number is (571)272-1452. The examiner can normally be reached Mon - Frid.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Prem C Singh can be reached at 571-273-6381. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/TAM M NGUYEN/Primary Examiner, Art Unit 1771
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