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 Amendment
The rejection of claims 16-30 and 33 under 35 USC § 112 is withdrawn by the examiner in view of the amendment filed on 4/15/2026.
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.
Claim 16-18 and 33 are rejected under 35 U.S.C. §103(a) as being unpatentable over Narayanaswamy et al., US 2018/0002609 A1 in view of Akimoto et al., “Hydrothermal Denitrogenation of Fuel Oil Derived from Municipal Waste Plastics in a Continuous Packed-Bed Reactor” Ind. Eng. Chem. Res. (2003) and in view of Hajekova et al. “Copyrolysis of naphtha with polyalkene cracking products; the influence of polyalkene mixtures composition on product distribution” ScienceDirect, pyrolysis 79 (2007) pages 196-204.
Narayanaswamy teaches providing a liquid hydrocarbon stream derived from mixed waste plastics via pyrolysis, i.e., a “second stream comprising hydrocarbons having 5 or more carbon atoms,” and feeding that stream together with hydrogen into a hydrocracker to obtain a hydrotreated/hydrocracked liquid product that is supplied to a steam cracker (Narayanaswamy ¶¶ [0005], [0011]–[0015], [0017], [0019]).
Narayanaswamy does not tech step B as claimed.
Akimoto teaches pre-treating fuel oil derived from thermally degraded waste plastics by contacting the oil with an aqueous alkaline medium (aqueous NaOH, pH ≥ 7) at subcritical hydrothermal temperatures of 250–325 °C (≥200 °C), thereby producing a treated mixture, followed by separation of the organic layer from the aqueous phase to obtain a treated (“product”) oil (Akimoto, Experimental Section; Results & Discussion). The separated organic layer corresponds to the claimed “organic phase including a pre-treated liquefied waste plastics material.”
Akimoto does not teach a post-treatment as claimed.
Hájeková teaches post-treatment conditioning of plastic-derived cracking products by blending them with heavy naphtha, a paraffinic material, to form a steam-cracking feedstock (Hájeková, Abstract; pp. 196–197).
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 hydrotreated stream of Narayanaswamy by blending with a paraffinic material as taught by Hájeková in order to condition the plastic-derived hydrocarbon stream for steam cracking and to tailor steam cracking product distribution and olefin yields, because Hájeková expressly teaches that blending with naphtha influences cracking performance and resulting olefin production.
Claim 17
Narayanaswamy expressly teaches feeding the hydroprocessed liquid stream to a steam cracker to produce light olefins (Narayanaswamy ¶¶ [0005], [0011]–[0015]).
Claims 18–23
Narayanaswamy teaches reduction of chloride content in plastic-derived streams, including targets of ≤10 ppm and <1 ppm chloride in downstream streams, and teaches hydrocracking to saturate olefins prior to cracking (Narayanaswamy ¶¶ [0016], [0023], [0070]–[0074]; Examples 6–8).
Akimoto teaches that alkaline hydrothermal processing of plastics-derived oils removes heteroatoms including chlorine and nitrogen at ≥200 °C using aqueous NaOH (Akimoto, Results & Discussion; Figures 2–4). Selection of specific contaminant or olefin content ranges and steam-cracker-feed properties represents routine result-effective optimization of known pretreatment and hydroprocessing steps.
Claims 24–28
Narayanaswamy teaches liquefied waste plastics obtainable by thermal degradation (pyrolysis), fractionation and splitting of plastic-derived streams, hydrotreating with supported NiMo/CoMo catalysts on alumina, and downstream separation/distillation (Narayanaswamy ¶¶ [0019], [0023], [0032]).
Hájeková teaches blending with paraffinic naphtha for steam-cracker feed preparation. Specifying paraffin-rich (including renewable) paraffinic materials and conventional separations constitutes an obvious selection among known alternatives.
Claim 33
Narayanaswamy’s detailed hydrocarbon analyses of hydrocracked and cracked liquid products explicitly report measurable naphthene contents within liquid paraffinic streams.
Akimoto further teaches that fuel oils and paraffinic fractions derived from thermal degradation of mixed waste plastics and subsequently refined (including hydrothermal and hydroprocessing treatments) characteristically contain naphthenes in minor but non-zero amounts, typically within single-digit to low-teens weight percent ranges, depending on processing severity and feed composition (Akimoto, Tables 1–4; Discussion, “Physical and Physicochemical Properties of Refined Fuel Oil”). Akimoto expressly demonstrates paraffinic fuel fractions containing naphthenes well within the claimed 0.01–15.00 wt.% range.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to operate the integrated plastic-to-hydrocarbon process of Narayanaswamy under known hydrocracking and cracking severities so as to obtain a paraffinic material having a naphthenes content within the claimed range, as taught and exemplified by Akimoto, because naphthene formation and retention in paraffinic refinery streams is a predictable result of hydrocracking and cracking severity optimization, and the claimed range represents a result-effective variable routinely controlled in petroleum and plastic-derived hydrocarbon processing.
Claims 29 and 30 are rejected under 35 U.S.C. 103 as being unpatentable over references as applied to claim 16 above, and further in view of Blackwell et al. (US 7,258,848 B1)
The process Narayanaswamy of is as discussed above.
Narayanaswamy teaches scrubbing acid gases from process gas streams, including liquid scrubbing approaches (Narayanaswamy ¶ [0019]).
Narayanaswamy does not teach a step of washing the gaseous effluent with an acidic liquid medium.
Blackwell teaches a step of removing contaminates from an acid gas by utilizing acidic liquid medium (e.g., sulfuric acid). See abstract; claim 1.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to apply Blackwell’s acidic gas-washing technique to the gaseous effluent of Narayanaswamy’s hydrotreating step as a predictable gas-cleanup alternative.
Response to Arguments
Applicant’s arguments filed April 6, 2026 have been fully considered but are not persuasive.
Applicant argues that Hajekova only teaches blending naphtha with polyalkene oil/wax fractions to address semi-solid feed handling and coking problems and that Narayanaswamy does not disclose such problems. However, the rejection does not rely solely on Hajekova for solving semi-solid feed handling issues. Rather, Hajekova additionally teaches that blending plastic-derived hydrocarbon streams with naphtha affects steam cracking behavior, conversion, and resulting olefin product distribution during steam cracking (Hajekova, pp. 197–198, Section 2.3). Narayanaswamy teaches integrated pyrolysis, hydroprocessing, and steam cracking of plastic-derived hydrocarbon streams for production of light olefins and aromatics (Narayanaswamy ¶¶ [0005], [0011]–[0015], [0021]–[0031]). 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 hydrotreated stream of Narayanaswamy by blending with a paraffinic material as taught by Hajekova in order to condition the plastic-derived hydrocarbon stream for steam cracking and to tailor steam cracking product distribution and olefin yields, because Hajekova expressly teaches that blending with naphtha influences cracking performance and resulting olefin production. The fact that Narayanaswamy’s streams may already be hydrotreated or possess relatively low olefin and chloride contents does not teach away from further feed conditioning prior to steam cracking.
Applicant further argues that the claimed combination of pretreatment step (B) followed by hydrotreatment step (C) allegedly provides unexpected silicon-removal performance and reduced fouling. These arguments are not persuasive because the claims do not recite any particular silicon-removal mechanism, fouling reduction performance, hydrotreatment efficiency improvement, or hydrogen-consumption reduction beyond broadly recited contaminant ranges. Akimoto teaches alkaline hydrothermal pretreatment of waste-plastics-derived oils using aqueous NaOH at temperatures above 200 °C followed by separation of the treated organic layer, thereby removing contaminants from the plastics-derived oil prior to downstream processing (Akimoto, Experimental Section; Results and Discussion). Narayanaswamy teaches subsequent hydroprocessing of plastics-derived hydrocarbon streams and removal of contaminants during integrated upgrading operations (Narayanaswamy ¶¶ [0011], [0019], [0023], [0070]–[0074]). One having ordinary skill in the art would reasonably have expected pretreatment prior to hydrotreatment to improve downstream processing by reducing contaminants. Moreover, no comparative evidence has been provided demonstrating unexpectedly superior results relative to the closest prior art.
Applicant additionally argues that Hajekova does not expressly disclose a paraffinic material having at least 60 wt.% paraffins as recited in claim 27. However, Hajekova teaches blending with heavy naphtha for steam cracking feed preparation, and paraffinic content of steam cracking feedstocks is a result-effective variable routinely selected and optimized in petrochemical feed formulation. Narayanaswamy further teaches hydroprocessed streams comprising paraffins, isoparaffins, naphthenes, and aromatics suitable for steam cracking (Narayanaswamy ¶¶ [0021]–[0033]; Examples 6–10). Selection of a paraffinic blending material having the claimed paraffin content would have constituted an obvious optimization of known steam cracking feed compositions.
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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