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 claim 28 under 35 USC § 102(a)(1) anticipated by Praddeep et al. (US 2022/0041940 A1) is withdrawn by the examiner in view of the amendment filed on 1/29/2026.
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.
Claims 1-3, 5-10, 12-17, 19-24 and 26-28 are rejected under 35 U.S.C. 103 as being unpatentable over Praddeep et al. (US 2022/0041940 A1) in view of Timken (US 11,174,436 B2).
Praddeep discloses
Selecting waste plastics containing polyethylene and/or polypropylene. See ¶¶ [0019], [0021], [0023], [0056], teaching PE and PP-containing waste plastics.
Preparing a blend of petroleum and the selected plastic, with the blend comprising about 20 wt. % or less plastic. See ¶¶ [0024]–[0026], teaching blends containing 0.1–15 wt.% waste plastic co-fed with VGO/petroleum feed.
Passing the blend to a refinery crude unitPraddeep feeds the plastic–petroleum blend to an FCC riser and to other refinery conversion units (FCC, hydrocracking), which under the BRI standard and in view of applicant’s own specification (e.g., ¶¶ [0047], [0053], [0056]) are refinery crude units. Applicant explicitly treats “refinery unit” and “refinery crude unit” interchangeably. FCC units, hydrocrackers, and associated refinery feed-processing units all qualify as “refinery crude units” under the broadest reasonable interpretation.
Claim 1
Praddeep teaches co-conversion of waste plastics and petroleum-derived hydrocarbon feedstock in an FCC riser reactor ([0001], [0013], [0046]). It discloses waste plastics including polypropylene and polyethylene ([0023], [0056]) and that waste plastic is 0.1–15 wt.% of the total feed mix ([0026], [0052]), which falls within “about 20 wt.% or less.” Hydrocarbon feed is spray-fed to the riser bottom and waste plastic is conveyed from a supply vessel into the same bottom section, where the plastic thermally decomposes and catalytically cracks with the hydrocarbon feed ([0013]–[0014], [0046]–[0047], [0062]–[0064]). This inherently forms a blend of petroleum and waste plastic at reaction conditions, and molten-plastic embodiments provide a hot homogeneous blend ([0058], [0065]–[0067]). Praddeep further teaches production of LPG and light olefins including propylene, along with gasoline, LCO, HCO and other distillates ([0012], [0047], [0074]–[0076]).
Praddeep does not teach the blending step in a preparation unit.
Timken teaches integrating plastic-derived hydrocarbon material into a refinery crude distillation unit, recovering LPG containing C₃ olefins and paraffins, separating C₃ olefins and C₃ paraffins, and sending C₃ olefins to a propylene polymerization reactor (Timken, Abstract and corresponding description).
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 Praddeep to adapt the co-processing concept of Praddeep (plastic + petroleum feed at 0.1–15 wt.% plastic generating LPG and propylene) into the crude-unit-centered configuration of Timken because further process the product from the FCC of Praddeep to produce desirable product as suggested by Timken is within the level of one of skill in the art.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to prepare a homogeneous liquid blend of petroleum and waste plastic prior to introduction into the refinery unit in order to improve feed handling, distribution, and operational stability, since uniform feed introduction is a well-known refinery engineering objective and predictable solution to avoid localized feed maldistribution. Improved feed uniformity and operational stability are well-recognized process design considerations. See KSR v. Teleflex.
Claim 2:
Praddeep teaches separation of product vapors into naphtha, light cycle oil, heavy cycle oil, clarified oil, plus LPG and fuel gas ([0013]–[0014], [0047], [0064], [0074]–[0076]). Timken teaches a crude unit separating gasoline and heavy fractions (e.g., VGO, atmospheric residue) as standard distillation cuts. When implementing the Praddeep plastic-co-conversion within Timken’s crude-unit scheme, recovery of gasoline and heavy fractions is inherent to crude distillation.
Claim 3
Praddeep teaches embodiments where waste plastic is kept molten and supplied in liquid form ([0058], [0065]) and where hydrocarbon feed is preheated and contacted with hot regenerated catalyst at 650–750 °C in the riser bottom ([0047], [0062]–[0064]). A molten plastic feed and a hot liquid hydrocarbon feed entering the same mixing zone inherently form a hot, substantially homogeneous mixture.
Claim 5
Praddeep shows that co-conversion produces significant propylene (C₃=) in the LPG fraction ([0074]–[0075]).
Timken teaches separating C₃ olefins from LPG and feeding propylene to a propylene polymerization reactor to make polypropylene.
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 Praddeep by routing the propylene generated in Praddeep’s LPG to a polypropylene reactor as suggested in Timken to produced desirable polymer.
Claim 6
Praddeep teaches waste plastics including polypropylene, polyethylene, polystyrene, PET, including metal-additized multilayer plastics ([0023], [0056]). These correspond to common packaging and film plastics that encompass the claimed groups.
Claim 7
Praddeep discloses production of gasoline-range material (C₅–210 °C) and its separation in the fractionator and GASCON section ([0047], [0064], Tables 4–5). In a refinery context, sending such gasoline to a blending pool is standard practice.
Claim 8
Praddeep teaches that product vapors are sent to a fractionator and gas concentration section to separate naphtha and heavier cuts, including light cycle oil and heavy cycle oil ([0047], [0064]).
Timken teaches routing crude-unit naphtha and heavy fractions to downstream units such as hydrotreaters, reformers, and other refinery processes to produce clean gasoline, diesel, and jet fuels.
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 Praddeep by integrating Praddeep’s plastic co-conversion into Timken’s crude-unit/downstream scheme to produce clean gasoline, diesel, and jet fuels.
Claim 9
Praddeep teaches plastic dosing of 0.1–15 wt.% in the total feed mix ([0026], [0052]). Timken teaches introducing plastic-derived streams to the crude unit up to around 20 vol% of the crude-unit feed.
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 Praddeep by choosing up to 50 vol.% for the plastic–petroleum blend because it is a routine optimization of blend ratio in view of process severity, product slate, and heat balance considerations, well within the skill of the art.
Claim 10
Timken already teaches crude-unit plastic-derived feed up to ~20 vol%; extending that upper limit to 25 vol% is a minor, predictable variation. In combination with Praddeep’s 0.1–15 wt. % plastic range, setting an upper limit of 25 vol% would have been an obvious design choice.
Claim 12
Praddeep explicitly states that the liquid hydrocarbon feedstock is selected from naphtha to vacuum gas oil, vacuum residue, atmospheric residue, deasphalted oils, shale oil, coal tar, clarified oil, residual oils, heavy waxy distillates, foots oil, slop oil or blends thereof ([0049]). These examples include AGO, VGO, atmospheric residue, and heavy petroleum-derived stocks.
Claim 13
Praddeep teaches that product vapors are separated into naphtha, light cycle oil, heavy cycle oil, clarified oil ([0047], [0064]), and that feeds/products can include cracked components from FCC, hydrocracking, and coking ([0049]). Those components encompass FCC naphtha, gasoline, diesel-range streams, and aromatic solvents.
Claim 14
Praddeep, as discussed for claim 1, teaches selecting PE/PP plastics ([0023], [0056]), co-feeding them with petroleum in a 0.1–15 wt.% range ([0026], [0052]), creating a blend in the riser bottom, and producing LPG and propylene ([0012], [0047], [0074]–[0075]).
Timken teaches recovering a C₃ paraffin/olefin mixture from crude-unit streams, separating C₃ olefins and C₃ paraffins, and sending C₃ paraffins to a propane dehydrogenation unit (PDH) to produce additional propylene, which is then polymerized.
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 Praddeep by seeking to maximize propylene generation from plastic-derived and petroleum-derived LPG in an integrated refinery would have been motivated to apply Timken’s C₃ separation and PDH configuration to the LPG streams produced by the Praddeep co-conversion system, including routing C₃ paraffins to PDH.
Claim 15
Timken explicitly teaches that propylene from PDH is sent to a propylene polymerization reactor to produce polypropylene.
Claim 16
Same reasoning as for claim 2: Praddeep teaches gasoline and heavier cuts; Timken supplies the crude-unit context and standard gasoline/heavy-fraction separation.
Claim 17
Same as claim 3: molten plastic + hot petroleum feed in Praddeep yield a hot homogeneous mixture at the riser base.
Claim 19
Same as claim 5: Praddeep provides propylene-containing LPG; Timken teaches its polymerization to polypropylene.
Claim 20
Same as claim 6: covered by Praddeep’s plastics list ([0023], [0056]).
Claim 21
Same as claim 7: gasoline blending is conventional.
Claim 22
Same as claim 8: Praddeep + Timken give naphtha and heavy fractions and standard downstream upgrading.
Claim 23
Same as claim 9: ratio optimization between Praddeep’s 0.1–15 wt.% and Timken’s ~20 vol%.
Claim 24
Same as claim 10: minor variation around Timken’s upper limit. Claim 24 is obvious over Praddeep in view of Timken.
Claim 26
Same as claim 12: exactly listed in Praddeep [0049].
Claim 27
Same as claim 13: covered by Praddeep’s feed and product lists ([0047], [0049], [0064]).
Claim 28 (broadest claim)
Same as claim 1.
Claims 29-31 and 33-34 are rejected under 35 U.S.C. 103 as being unpatentable over references as applied to claims 1-28 above, and further in view of Timken US 20210189250 A1 (Timken ’250).
Praddeep + Timken supply: PE/PP plastic selection, the ≤20 wt.% plastic blend, crude-unit integration, and recovery of a heavy fraction.
Timken ’250 teaches routing heavy crude-unit fractions to hydrocracking and routing heavy hydrocracker effluent to an isomerization-dewaxing unit to produce base oils. See abstract; figures 1-2 and their descriptions.
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 process of Praddeep by applying Timken ’943’s heavy-fraction upgrading sequence to the heavy fraction produced in the Praddeep/Timken process.
Claim 30
Timken ’250 explicitly teaches hydrofinishing base oil after isomerization-dewaxing. In view of Timken ’250, routing base oil to hydrofinishing is an obvious step.
Claim 31
Same as claim 1. Praddeep + Timken together teach plastic/petroleum blending, ≤20 wt.%, and crude-unit integration
Claims 33-34
Praddeep teaches production of gasoline, LPG, and middle-distillate range streams ([0012], [0047], [0074]–[0075]).
Praddeep teaches that waste plastic can be kept in molten form in the supply vessel and supplied to the riser in liquid form ([0058], [0065]) and that thermal energy from hot regenerated catalyst may be used to melt plastic ([0067]).
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 Praddeep by heating and cooling as claimed because one of skill in the art would recognize that heating plastics above their melting point and mixing them with petroleum feed is a known way to form a uniform mixture, and that cooling such a blend below the melting point (e.g., for storage, transport, or controlled feeding) is a routine step.
Timken teaches handling of plastic-derived streams prior to refinery introduction.
Preparation, storage, and reheating of refinery feedstock are conventional petroleum handling practices. It would have been obvious to store blend and reheated prior to injected as standard refinery logistics.
Praddeep, as discussed for claim 1, teaches selecting PE/PP plastics ([0023], [0056]), co-feeding them with petroleum in a 0.1–15 wt.% range ([0026], [0052]), creating a blend in the riser bottom, and producing LPG and propylene ([0012], [0047], [0074]–[0075]).
Timken teaches recovering a C₃ paraffin/olefin mixture from crude-unit streams, separating C₃ olefins and C₃ paraffins, and sending C₃ paraffins to a propane dehydrogenation unit (PDH) to produce additional propylene, which is then polymerized.
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 Praddeep by seeking to maximize propylene generation from plastic-derived and petroleum-derived LPG in an integrated refinery would have been motivated to apply Timken’s C₃ separation and PDH configuration to the LPG streams produced by the Praddeep co-conversion system, including routing C₃ paraffins to PDH.
Response to Arguments
The argument that Pradeep does not create a homogeneous liquid blend is not persuasive because Pradeep teaches co-processing plastic and petroleum feed in refinery conversion systems. Even if Pradeep discloses separate introduction streams, pre-blending upstream constitutes an obvious alternative feed introduction method to improve distribution and handling. Feed uniformity is a known refinery objective. The modification would have been predictable and within ordinary skill.
The argument that separate injection causes severe coke formation is not persuasive. The Declaration (Table 5) compares:
• 100% VGO vs. 5% plastic blended feeds
The data show:
• Coke increase from 4.9 wt.% to ~6 wt.%• Slight conversion increase• No catastrophic failure• No refinery inoperability
The Declaration does not compare:
• Separate injection vs pre-blending• Localized plastic concentration effects
Thus, no nexus exists between alleged advantages and the claimed preparation step.
Further, the claims do not recite reduced coke formation or catalyst uniformity.
Under In re Grasselli and In re Peterson, objective evidence must be commensurate in scope. It is not.
Predictability
If plastic has higher coking tendency than petroleum, uniform mixing would predictably distribute coke more uniformly.
Such optimization is a routine process engineering consideration.
Predictable improvements do not render a claim non-obvious. See KSR; In re Aller.
Timken References
Timken reinforces:
• Processing of plastic-derived hydrocarbon streams• Integration into refinery units
The combination remains proper.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
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.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/TAM M NGUYEN/Primary Examiner, Art Unit 1771