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 1-3 and 5-23 are rejected under 35 U.S.C. §103 as being unpatentable over Bachmann Nielsen (WO 2021/209555 A1) in view of Dahlstrand et al. (US 2018/0265794 A1).
Bachmann Nielsen discloses a process for converting lignin or lignocellulosic biomass to renewable liquid products comprising providing a feed mixture comprising lignin feedstock and a recycled product fraction, thermally liquefying the feed mixture at temperatures, pressures, and residence times overlapping the claimed ranges, separating the resulting product mixture, fractionating the liquid product to recover a recycled product fraction including a fraction having a boiling point between about 300°C and 600°C, and recycling at least a portion of the recovered fraction to the liquefaction process (Bachmann Nielsen, pp. 7-11, Fig. 23). Bachmann Nielsen further teaches optional recycle of lower-boiling fractions, preparation of the feed mixture, continuous or batch operation, fractionation of the liquid products, and thermal liquefaction conditions overlapping those recited in claims 1-3, 6, 8-15, 19, and 23.
Bachmann Nielsen, however, does not expressly disclose obtaining the lignin feedstock by filtration, nanofiltration, acid precipitation, or membrane fractionation; specific molecular-weight, moisture, and oxygen properties of the lignin feedstock; Kraft lignin separated from black liquor having the claimed impurity level; directing a fraction to hydroprocessing; or the claimed lignin loading in the feed mixture.
Dahlstrand teaches preparing lignin feedstock by membrane filtration, acid precipitation, and membrane fractionation (¶¶ [0098]-[0101]); lignin feedstocks having overlapping molecular-weight ranges (¶ [0062]); lignin derived from black liquor and Kraft lignin (¶¶ [0057]-[0060]); hydroprocessing lignin-derived fractions and recycling the resulting green carrier liquid (Fig. 3; ¶¶ [0065]-[0082]); and feed mixtures containing overlapping amounts of fresh lignin and recycled depolymerized lignin (¶¶ [0063], [0096]). Dahlstrand further teaches mixing fresh lignin with the recycled lignin-derived carrier liquid prior to thermal treatment (¶¶ [0049], [0051], [0065], [0066], [0070]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the process of Bachmann Nielsen with the teachings of Dahlstrand because both references are directed to the conversion of lignin into renewable liquid products by recycling lignin-derived product fractions as process solvent. Incorporating Dahlstrand's lignin feed preparation, filtration techniques, Kraft lignin feedstocks, hydroprocessing, and feed composition into the process of Bachmann Nielsen would have predictably improved lignin dissolution, reduced fresh solvent consumption, increased process efficiency, and utilized known lignin-processing techniques for their established functions.
Regarding claim 5, Dahlstrand teaches recovering a lighter gasoline-range fraction during fractionation (Fig. 3). Figure 3 depicts this gasoline fraction as comprising predominantly single-ring aromatic compounds (monoaromatics), while the heavier recycled green carrier liquid comprises higher molecular-weight aromatic compounds. Therefore, it would have been obvious to employ the lighter recycled fraction as a monoaromatic-rich fraction corresponding to the claimed second fraction.
Regarding claim 7, Dahlstrand teaches preparing lignin feedstock using membrane filtration, filtration, nanofiltration, and acid precipitation (¶¶ [0098]-[0101]). It would have been obvious to prepare the lignin feedstock using the purification techniques taught by Dahlstrand because such techniques remove ash, salts, and other impurities from lignin feedstocks, thereby improving feed quality, reducing fouling of downstream equipment, and improving liquefaction efficiency.
Regarding claim 10: Dahlstrand teaches filtering lignin-containing mixtures during feed preparation (¶¶ [0098]-[0101]). It would have been obvious to filter the prepared feed mixture before thermal liquefaction because removal of suspended solids and insoluble materials is a well-known process optimization for preventing plugging and improving reactor operability.
Regarding claim 16, Dahlstrand teaches lignin feedstocks having weight-average molecular weights overlapping the claimed value (¶ [0062]). It would have been obvious to select lignin feedstocks having molecular weights within the claimed range because molecular weight is a recognized result-effective variable affecting lignin solubility, viscosity, and conversion efficiency during liquefaction, and optimization of such properties would have been routine.
Regarding Claim 17, it would have been obvious to employ lignin feedstocks having moisture contents within the claimed range because the moisture content of industrial lignin is determined by the recovery and drying processes and represents a routine process variable selected according to handling, pumping, and reaction requirements.
Regarding claim 18, it would have been obvious to employ lignin feedstocks having oxygen contents within the claimed range because oxygen content is an inherent characteristic of lignin that varies according to biomass source and lignin isolation process, and selecting lignin having suitable oxygen content for liquefaction would have been an obvious matter of routine process optimization.
Regrading claim 20, Dahlstrand teaches Kraft lignin obtained from black liquor (¶¶ [0057]-[0060]). It would have been obvious to reduce residual black liquor impurities because purification of Kraft lignin improves product consistency, minimizes catalyst poisoning, reduces inorganic contamination, and enhances downstream processing efficiency.
Regarding claim 21, Dahlstrand teaches hydroprocessing lignin-derived fractions (Fig. 3; ¶¶ [0065]-[0082]). It would have been obvious to hydroprocess at least a portion of the recovered fraction because hydroprocessing is a conventional upgrading technique for reducing oxygen content, increasing fuel stability, and producing transportation fuels from lignin-derived oils.
Regarding claim 22, Dahlstrand teaches feed mixtures containing overlapping amounts of fresh lignin and recycled depolymerized lignin (¶¶ [0063], [0096]). It would have been obvious to employ lignin concentrations within the claimed range because the ratio of lignin feedstock to recycled solvent is a recognized result-effective variable affecting slurry viscosity, lignin dissolution, heat transfer, and reactor operability, and optimization of that ratio would have been within the ordinary skill of the art.
Claim 4 is rejected under 35 U.S.C. §103 as being unpatentable over Bachmann Nielsen in view of Dahlstrand, and further in view of Black et al. (US 4,962,271).
The processes of Bachmann Nielsen and Dahlstrand are as discussed above.
Black teaches selectively separating multi-ring aromatic hydrocarbons from heavy distillate streams. Black expressly teaches that the desired multi-ring aromatics include compounds having at least two rings, preferably three or more rings, including condensed and fused ring systems, biphenyl, diphenylmethane, triphenylmethane, and related structures. Black further demonstrates that membrane perstraction preferentially enriches 2-ring, 3-ring, and 4-ring aromatic compounds over single-ring aromatics, as shown by the compositional analyses in the examples. See col. 3, lines 20-65; example 1 and tables 1-4.
It would have been obvious to one of ordinary skill in the art to further separate the heavy recycled fraction of Bachmann Nielsen, as modified by Dahlstrand, using the selective separation technique taught by Black in order to obtain a first fraction enriched in di-, tri-, and tetra-aromatic compounds because Black teaches that such separation selectively concentrates multi-ring aromatics from heavy distillate streams. Doing so would have predictably produced a recycled solvent having a higher concentration of multi-ring aromatic compounds, which are known to possess strong solvency for aromatic feedstocks.
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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