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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 2/24/2026 has been entered.
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 1-8, 10, 14-16, and 22 are rejected under 35 U.S.C. 102(b) as being anticipated by Streiff et al. (US 2018/0371326 A1) in view of Subramani et al. (WO 2010/113174A1) and Evans et al. . (WO 2022/155525 A1).
Streiff discloses a fluid catalytic cracking (FCC) process wherein a waste plastic ([0079], [0083], [0086]) feedstock is melted to provide a neat form ([0079]). The melted feedstock is then contacted with a fresh catalyst ([0025]) and/or a deactivated catalyst ([0057]) comprising ZSM-5 ([0046]) in a FCC process to produce a product which is then fractions and recovered ([0079]) to produce a fraction comprising gasoline ([0083], [0084]). The FCC process is operated at a temperature of from 350-600o C ([0079]). The plastic comprises one or more polyesters and one or more polyolefins (e.g., high density polyethylene and polypropylene) ([0070], [0086] [0092]).
Streiff does not teach that the catalyst comprises at least about 80 wt. % of a phosphorus-containing ZSM-5, does not teach that the catalyst is treated with steam prior to contact with a feedstock, does not explicitly teach that the polyethylene having a melting point of from about 35o C to 100o C or the low or high density of the polyolefins as claimed, does not teach that the plastic feedstock is solid or a semi-melted state. and does not teach that the product stream comprises about 30-60 wt. % of gasoline fraction.
Evans discloses a cracking catalyst comprising about 90 wt. % of phosphorus containing ZSM-5. See abstract; [0018],[0039].
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 Streiff by utilizing a catalyst comprising at least 80 wt. % of phosphorus containing ZSM-5 as suggested by Evans in order to enhance cracking selectivity.
Subramani discloses a FCC process wherein the catalyst is deactivated by treating with steam at a temperature of 810o C. See pages 17, lines 9-20; page 19, lines 2-5; page 22, lines 1-8; page 23, lines 1-8.
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 Streiff by treating the catalyst with steam as suggested by Subramani to increase the production of LPG and propylene.
Regarding the limitation that the catalyst is the only catalyst, once it is obvious to employ a high-loading ZSM-5 cracking catalyst as suggested by Evans, it would have been an obvious design choice to operate the cracking process using that catalyst formulation alone rather than in combination with other FCC catalysts, depending on desired product selectivity and catalyst inventory considerations. Therefore, 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 process of Streiff by employing a steam-treated, high-loading ZSM-5 cracking catalyst that is free of metal impregnation, as suggested by Subramani and Evans, in order to tune catalyst acidity and gasoline selectivity.
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 Streiff by utilizing a low and high density of polyethene and polypropylene as claimed because it is within the level of one of skill in the art to use any type of density of polyethene and polypropylene with expectation that either high or low density polyethene and polypropylene would be effectively treated in the process of Streiff. Consequently, a low density polyethylene would have a melting point as claimed.
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 Streiff by utilizing a plastic feedstock in a solid or semi-melted neat-form because it would be expected the such neat-forms would be successfully treated in the process of Streiff because the mixture of catalyst plastic feedstock is then heated up to a temperature of from 350-600o C and reacted in the reactor.
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 Streiff by producing a product stream comprising 30-60 wt. % of gasoline as claimed because of the similarities between the claimed process and the modified process of Streiff.
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over references as applied to claim 1 above, and further in view of Narayanaswamy et al. (US 2014/0228606 A1).
The process of Streiff is as discussed above.
Streiff does not disclose that the catalyst is regenerated.
The process of Narayanaswamy is as discussed below.
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 Streiff by regenerating the catalyst as suggested by Narayanaswamy to at least partially remove coke to renew the catalyst.
Claims 1-8, 10, 14-17, and 22-26 are rejected under 35 U.S.C. 103 as being unpatentable over Narayanaswamy et al. (US 2014/0228606 A1) in view of Evans et al. . (WO 2022/155525 A1) and Subramani et al. (WO 2010/113174 A1).
Narayanaswamy teaches process for converting solid waste plastic feedstock to hydrocarbon product [0134]. The feedstock comprising low and high density of polyethylene ([0016], table 2) in a neat form is contacted with a fresh/deactivated catalyst comprising ZSM-5 ([0013], table 1, [0069]) in FCC reaction zone to produce a product comprising gasoline ([0108], [0109]). The FCC reaction zone is operated at a temperature of from 420-730o C ([0006], [0017], [0019]) and at a catalyst to oil ratio from about 2:1 to about 10:1 ([0081]). The catalyst is treated with steam (figure 1, stripper) at a temperature of at least 500o C. The catalyst is regenerated at a temperature of from 600-800o C ([0063]), at a hydrocarbon partial pressure of 100 to about 1100 kPa ([0081]).
Narayanaswamy does not teach that the catalyst comprising 80 wt. % of ZSM-5, does not teach that the catalyst is treated with steam prior to contact with a feedstock, does not explicitly teach that the polyethylene having a melting point of from about 35o C to 100o C or the low or high density of the polypropylene as claimed, does not teach that the plastic feedstock is semi-melted state or liquid state, and does not teach that the product stream comprises about 30-60 wt. % of gasoline fraction.
Evans discloses a cracking catalyst comprising about 90 wt. % of ZSM-5 and 0-20 wt. % of phosphate. See abstract; [0018],[0039], [0041].
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 Narayanaswamy by utilizing a catalyst comprising about 80 wt. % of ZSM-5 as suggested by Evans in order to enhance cracking selectivity.
Subramani discloses a FCC process wherein the catalyst is deactivated by treating with steam. See pages 17, lines 9-20; page 19, lines 2-5; page 22, lines 1-8; page 23, lines 1-8.
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 Narayanaswamy by treating the catalyst with steam as suggested by Subramani to increase the production of LPG and propylene.
Regarding the limitation that the catalyst is the only catalyst, once it is obvious to employ a high-loading ZSM-5 cracking catalyst as suggested by Evans, it would have been an obvious design choice to operate the cracking process using that catalyst formulation alone rather than in combination with other FCC catalysts, depending on desired product selectivity and catalyst inventory considerations. Therefore, 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 process of Narayanaswamy by employing a steam-treated, high-loading ZSM-5 cracking catalyst that is free of metal impregnation, as suggested by Subramani and Evans, in order to tune catalyst acidity and gasoline selectivity.
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 Narayanaswamy by utilizing a low and high density of polypropylene as claimed because it is within the level of one of skill in the art to use any type of density of polypropylene with expectation that either high or low density polypropylene would be effectively treated in the process of Narayanaswamy. Consequently, a low density polyethylene would have a melting point as claimed.
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 Narayanaswamy by utilizing a plastic feedstock in a semi-melted, or melted neat-form because it would be expected the such neat-form would be successfully treated in the process of Narayanaswamy because the mixture of catalyst plastic feedstock is then heated up to a temperature of from 600-800o C and reacted in the reactor.
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 Narayanaswamy by producing a product stream comprising 30-60 wt. % of gasoline as claimed because of the similarities between the claimed process and the modified process of Narayanaswamy.
Regarding new claim 22, 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 Narayanaswamy’s teaching that gasoline yield is a key tuning target and is routinely adjusted by catalyst composition and FCC severity, to optimize the operating conditions and catalyst formulation of the combined Narayanaswamy/Evans/Subramani process such that the gasoline fraction in the total product stream falls within a commercially useful range such as about 30 to about 60 wt.%, as a matter of routine optimization of result-effective variables (see MPEP § 2144.01).
Regarding claims 23-24, As applied to claim 1, it is implicit from Narayanaswamy that fresh FCC catalysts and additives are manufactured substantially free of such heavy metal contaminants and that metal contamination arises only as a result of exposure to hydrocarbon feed and metals present therein.
Regarding claim 23 additionally recites that “the non-metal impregnated, steam-treated deactivated catalyst is free of a metal contaminant.” Claim 23 does not recite any structural change to the ZSM-5-containing additive itself, but merely characterizes the catalyst by its contamination history (fresh vs. used). Selecting a fresh, essentially metal-free FCC light olefin additive for use in a plastics FCC process, rather than an equilibrated, metal-contaminated catalyst, would have been an obvious design choice to one of ordinary skill in the art in view of Narayanaswamy’s teachings on ECAT and the well-known fact that fresh additives are initially free of feed-borne metals. The presence or absence of contaminant metals such as Ni or V is not a fundamental structural difference in the ZSM-5/additive formulation, but rather an inherent condition of use dictated by whether the catalyst has been previously circulated. As such, reciting that the additive is “free of metal contaminant” does not impart patentable weight beyond the obvious selection of a fresh catalyst.
Regarding claim 24 further specifies that the metal contaminant comprises one or more of sodium, potassium, magnesium, calcium, vanadium, nickel, and iron. Such metals are recognized in the FCC art as typical contaminants arising from crude-derived feeds and feed pretreatment (see, e.g., Narayanaswamy’s specific mention of vanadium in equilibrium FCC catalyst at ¶[0057], and Applicant’s own specification describing similar metal species as typical contaminants). It would have been obvious for one of ordinary skill in the art, when characterizing a “metal-contaminated” versus “metal-free” FCC catalyst, to identify conventional FCC contaminant metals such as Na, K, Mg, Ca, V, Ni, and Fe. Reciting this illustrative list of conventional FCC contaminants does not confer patentability (see MPEP § 2144.05 regarding selection of known species and characterization of known contaminants).
Regarding claims 25 and 26, As applied to claim 1, Evans teaches the use of ZSM-5-based light olefins additives at high loadings (about 80 wt.% and higher) and 0-20 wt. % phosphate in FCC catalyst formulations.
Evans teaches that increasing ZSM-5 content in FCC light olefin additives increases cracking activity and light olefin production. In view of Evans, once it is obvious to employ ≥80 wt.% ZSM-5 + phosphorus additive because Evans teaches the catalyst comprises about 80 wt. % of zeolite and 0-20 wt. % phosphate in the catalyst, it would have been an obvious matter of routine optimization to further increase the proportion of the additive to 90 wt.%, 95 wt.%, or even 100 wt.% to achieve a desired selectivity profile, especially in a system focused on light olefins and gasoline production. The exact numerical threshold (80, 90, 95, 100 wt.%) represents routine tuning of the proportion of additive in the circulating catalyst inventory.
Response to Amendment
Applicant amended claim 1 to recite that the catalyst is:
steam-treated
non-metal impregnated
comprises ≥80 wt.% phosphorus-containing ZSM-5 additive
and is the only catalyst
However, these limitations do not materially distinguish the claimed process from the prior art combinations.
Streiff teaches catalytic depolymerization of plastic waste using FCC catalysts containing zeolitic materials such as ZSM-5 and processing plastic feeds to produce gasoline fractions (Streiff ¶[0045]–[0046], ¶[0065]–[0070], ¶[0079], ¶[0084]). Streiff further teaches that FCC catalysts may be fresh FCC catalysts or equilibrium FCC catalysts (ECAT) (¶[0056]). Fresh FCC catalysts are inherently free of contaminant metals prior to exposure to hydrocarbon feedstocks. Accordingly, selecting a catalyst that is not metal impregnated represents the obvious selection of a fresh catalyst rather than a spent catalyst containing metal contaminants.
Applicant argues that Subramani teaches steam treating metal-contaminated catalysts and therefore cannot teach the claimed feature. This argument mischaracterizes the relevance of Subramani. Subramani teaches that FCC catalysts are hydrothermally deactivated by steaming (Subramani, p.17 lines 9-19). Hydrothermal steam treatment is a well-known method for modifying the acidity and catalytic behavior of zeolite-containing FCC catalysts. The purpose of citing Subramani is not limited to the specific catalyst compositions used in Subramani, but rather to show that steam treatment of FCC catalysts to modify catalytic properties was known in the art. It would have been obvious to one of ordinary skill in the art to apply this known technique to the FCC catalysts used in the plastic cracking process of Streiff or Narayanaswamy in order to adjust catalyst acidity and selectivity. Whether the catalyst contains metals prior to steaming does not change the fundamental teaching that steam treatment modifies catalyst performance.
Applicant argues that the cited references do not disclose the use of the catalyst as the only catalyst. However, determining whether a process uses:
a single catalyst formulation, or
a mixture of catalyst and additives
is a routine design choice within the ordinary skill in FCC process engineering. Evans teaches ZSM-5 additives used to promote cracking reactions and increase gasoline/light-olefin production (Evans abstract; ¶[0018], ¶[0039]). Once it is obvious to employ a high-loading ZSM-5 catalyst system, a skilled artisan would recognize that the process could be operated using that catalyst alone depending on desired product selectivity. Therefore, the limitation that the catalyst is the only catalyst represents a predictable implementation choice and does not render the claimed process non-obvious.
Applicant asserts that the rejection relies on hindsight reconstruction.
This argument is not persuasive because the rejection relies on explicit teachings in the prior art:
• Streiff teaches plastic depolymerization using FCC catalysts producing gasoline fractions.• Subramani teaches steam treatment of FCC catalysts to modify catalyst behavior.• Evans teaches high-loading ZSM-5 additives for cracking reactions.
The combination of these references reflects the ordinary skill in the art of FCC catalyst design, where catalyst acidity, composition, and additive content are routinely adjusted to tune product distribution. The rejection therefore relies on predictable modifications suggested by the prior art, not on hindsight reconstruction.
Conclusion
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/TAM M NGUYEN/Primary Examiner, Art Unit 1771