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
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 28–46 are rejected under 35 U.S.C. §103 as being unpatentable overFoody et al. (US 9,108,894 B1) in view of Lehoux et al. (US 2016/0186072 A1) and further in view of Antonini et al. “hydrogen production from natural gas and biomethane with carbon capture and storage” Sustainable Energy & Fuels, 2020, 4, 2967–2986. Foody teaches producing fuel from methane-containing feedstocks, including biomass-derived sources (col. 3–5), via methane reforming to produce syngas comprising hydrogen and carbon monoxide, separating hydrogen, and feeding the hydrogen to downstream fuel-producing processes, while generating CO₂ and capturing CO₂ from reforming-related streams including syngas and/or flue gas and providing such CO₂ for carbon capture and storage (CCS) to reduce greenhouse gas emissions and carbon intensity (col. 2, line 63 – col. 3, line 14; col. 5, lines 20–67; col. 7, lines 10–45; col. 18, lines 31–42; col. 24, lines 10–12), wherein CO₂ associated with biomass-derived feedstocks is inherently biogenic. Foody does not expressly disclose anaerobic digestion and digestate processing. Lehoux teaches anaerobic digestion producing biogas and digestate and processing the digestate including combustion to generate CO₂-containing flue gas (¶[0216]; Figs. 4–5).
Antonini et al. teach biomethane-derived reforming systems in which CO₂ is generated in both syngas and flue gas streams (p. 2971–2972; Fig. 1), captured from multiple process locations including syngas and flue gas (p. 2972–2973), and provided for permanent geological storage (p. 2973), thereby reducing lifecycle greenhouse gas emissions and carbon intensity, including achieving net-negative emissions when biogenic CO₂ is captured and stored (p. 2974–2976). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Foody to utilize biomethane produced via anaerobic digestion and digestate processing as taught by Lehoux and to capture CO₂ from multiple biomass-derived process stages and provide the captured CO₂ for substantially permanent storage as taught by Antonini et al. in order to further reduce greenhouse gas emissions and carbon intensity, since increasing capture and storage of CO₂ from known process streams predictably reduces lifecycle emissions.
Claims 29–35
Foody teaches producing fuels and fuel intermediates from hydrogen and/or syngas components (CO and/or CO₂), including hydrocarbons, alcohols, and other products (Foody, col. 6, lines 10–55; col. 8, lines 20–60). Use of hydrogen with CO and/or CO₂ in downstream synthesis (e.g., Fischer–Tropsch, alcohol synthesis) is well known.
Claim 36
Lehoux further teaches processing anaerobic-digestion residue by an airless spray-drying unit that separates water from the residue to provide dried solid residue, with the water optionally recycled to the anaerobic digester, and thereafter combusting the dried solid residue to generate supplemental heat (Lehoux ¶[0216]; Figs. 4–5).
Claims 37–38
Foody teaches that carbon capture and storage reduces lifecycle greenhouse gas emissions and carbon intensity (Foody, col. 2, line 63 – col. 3, line 14; col. 24, lines 10–12). The degree of carbon intensity reduction, including low or negative values. Antonini expressly teaches that permanent geological storage of biogenic CO₂ can produce negative lifecycle CO₂ emissions because biomass first removes CO₂ from the atmosphere and geological storage prevents the corresponding biogenic carbon from returning to the atmosphere (Antonini, pp. 2974–2976). Accordingly, providing sufficient biogenic CO₂ from the combined process for permanent storage so that the resulting hydrogen/fuel has a carbon intensity below zero would have been an obvious implementation of Antonini's expressly taught negative-emissions approach.
Claims 39 and 41
Lehoux teaches combustion of digestate producing flue gas comprising carbon dioxide (Lehoux ¶[0216]). Foody teaches capturing carbon dioxide from flue gas for CCS (Foody, col. 10, lines 5–30; col. 18, lines 31–42).
Claim 40
Foody teaches biomass feedstocks including agricultural residues (Foody, col. 4, lines 15–40).
Claim 42
Lehoux teaches processing biomass residues via thermal and chemical conversion processes (Lehoux ¶[0216]). 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 Lehoux by utilizing a wet oxidation because wet oxidation is a known alternative processing method.
Claim 43
Foody teaches methane reforming (including SMR) producing flue gas and capturing carbon dioxide from flue gas streams (Foody, col. 7, lines 10–45; col. 10, lines 5–30). Selection of flue gas as the capture source represents a known alternative.
Claim 44
Foody teaches using methane-containing streams both as feedstock and as fuel for reforming heat (Foody, col. 7, lines 30–60).
Claims 45–46
Obvious for the same reasons as claims 28-35.
Response to Arguments
Applicant's arguments have been fully considered but are not persuasive.
Applicant first argues that Foody, Lehoux, and Antonini, individually or collectively, fail to teach or suggest capturing biogenic CO₂ generated from digestate processing and providing the captured CO₂ for substantially permanent storage. In particular, Applicant argues that Lehoux ¶[0216] merely teaches burning dried residue to provide supplemental heat and does not itself teach capture or storage of the resulting CO₂, while Antonini's CCS is directed to CO₂ captured from hydrogen-production syngas rather than digestate-combustion flue gas. The argument is not persuasive because the rejection is based upon the combined teachings of the references and does not require Lehoux, by itself, to disclose the subsequent capture and geological storage of the CO₂ generated by digestate combustion. Lehoux teaches anaerobic digestion and the resulting residue/digestate and expressly teaches burning dried residue to generate supplemental heat (Lehoux ¶[0216]; Figs. 4–5). Combustion of such biomass-derived residue necessarily produces a combustion exhaust containing carbon dioxide derived from the biomass. Foody teaches CO₂ capture and underground storage in connection with processes utilizing non-fossil organic material. Antonini further teaches CCS in biomethane-based hydrogen production and establishes that geological storage of biogenic CO₂ constitutes negative CO₂ emissions because the stored carbon was previously removed from the atmosphere by biomass (Antonini, pp. 2974–2976, 2982).
Applicant's reliance on Lehoux ¶[0034], which identifies CO₂ from a separate ethanol process or atmospheric capture as possible sources of CO₂ for dry reforming, does not establish teaching away. Applicant itself acknowledges that Lehoux teaches burning the dried residue but argues that Lehoux selects other sources when additional CO₂ is desired for dry reforming. Lehoux's identification of alternative CO₂ sources for use as a dry-reforming reactant does not criticize, discredit, or otherwise discourage capture and storage of CO₂ generated from combustion of the biomass-derived residue. The proposed modification concerns capturing that CO₂ for CCS, not supplying it as Lehoux's dry-reforming reactant.
Applicant next argues that the stated motivation—further reducing lifecycle emissions by capturing and storing additional biomass-derived CO₂ - is conclusory because CO₂ capture, dehydration, compression, transport, and storage themselves consume energy and therefore additional capture does not necessarily reduce lifecycle emissions. Applicant further distinguishes Antonini's pre-combustion syngas capture from post-combustion capture of digestate flue gas. The argument is not persuasive. The rejection need not establish that every conceivable CO₂-capture configuration under every operating condition necessarily decreases lifecycle emissions. Rather, Antonini expressly evaluates CCS on a lifecycle basis and teaches the climate benefit of permanently storing biogenic CO₂, including the possibility of negative lifecycle emissions. Thus, the motivation is not based merely upon an unsupported assumption that "more capture is always better," but upon the prior art's express recognition that permanently preventing biomass-derived carbon from returning to the atmosphere can reduce net lifecycle GHG emissions. A person of ordinary skill, having Lehoux's known biomass-derived combustion stream available and Antonini's express teaching of the lifecycle benefit obtained by geological storage of biogenic carbon, would have had reason to apply known CO₂ capture and storage to that stream where the resulting lifecycle reduction justified the capture requirement.
Applicant also argues that flue gas may be more dilute, lower-pressure, and more difficult to process than syngas. Such differences do not establish nonobviousness. They concern the relative technical and economic desirability of alternative known CO₂ sources. The claims do not require a particular capture technology, energy consumption, capture efficiency, flue-gas CO₂ concentration, pressure, or economic performance. Nor does the evidence establish that capture from the combustion stream would have been technically inoperative. The existence of a more convenient CO₂ capture point does not render another known CO₂-containing process stream nonobvious for capture where the art supplies a reason to capture additional biogenic carbon.
Applicant further argues that the present application uniquely recognizes that a substantial portion of biomass carbon remains in digestate and that capture of this additional carbon pool provides the asserted three-tier CCS advantage. This argument is not persuasive because obviousness does not require the prior art to recognize Applicant's precise explanation or quantify the digestate carbon pool in the same manner. Lehoux supplies the biomass-derived residue and its combustion, while Foody and Antonini supply CO₂ capture/storage and the recognized environmental benefit of storing carbon, particularly biogenic carbon. The claimed arrangement therefore results from applying the known CCS treatment to known biomass-derived CO₂ sources for the known purpose of reducing atmospheric/lifecycle CO₂.
Applicant additionally argues that substantially permanent storage of biogenic CO₂ would render Foody unsatisfactory for its intended purpose because Foody uses biogenic CO₂ as a carbon source to increase production of biogenic fuel and allegedly reserves underground storage for fossil CO₂. This argument is not persuasive. The proposed combination does not require eliminating Foody's utilization of biogenic CO₂ or diverting all of Foody's biogenic CO₂ from fuel production. Rather, Lehoux supplies an additional biomass-derived carbon stream generated by processing/combusting the digestate, and Antonini provides the reason for permanently storing available biogenic CO₂—namely, preventing carbon previously removed from the atmosphere from being returned thereto and thereby obtaining reduced or negative lifecycle emissions. Accordingly, the modification does not render Foody inoperative for its intended purpose; Foody's fuel-production function can be retained while additional available biomass-derived CO₂ streams are subjected to CCS.
Applicant's argument concerning claims 37 and 38 is persuasive only insofar as the prior rejection characterized carbon intensity itself as a result-effective process variable. Applicant correctly points out that CI is a lifecycle-calculated result rather than a directly manipulated operating parameter. However, this does not overcome the rejection as presently maintained. The Office does not rely on routine optimization of CI. Rather, Antonini expressly teaches that geological storage of biogenic CO₂ can provide negative lifecycle emissions. Thus, the claimed CI below zero would have been an expected result of employing sufficient permanent storage of biomass-derived CO₂ according to Antonini's teaching, rather than the result of routine optimization of CI as a process variable.
Accordingly, Applicant's arguments do not overcome the prima facie case of obviousness. The combined teachings provide Lehoux's anaerobic digestion and combustion of biomass-derived digestate/residue, Foody's CO₂ capture/storage and fuel-production framework, and Antonini's express teaching and motivation for geological storage of biogenic CO₂ to reduce lifecycle GHG emissions, including achieving negative emissions. The rejection of claims 28–46 under 35 U.S.C. 103 over Foody in view of Lehoux and further in view of Antonini is therefore maintained.
Conclusion
THIS ACTION IS MADE FINAL. 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 TAM M NGUYEN whose telephone number is (571)272-1452. The examiner can normally be reached Mon - Frid.
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/TAM M NGUYEN/Primary Examiner, Art Unit 1771
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