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The rejection of claims 1-20 under 35 USC § 103 over Narayanaswamy in view of Khan is withdrawn by the examiner in view of the response filed on 6/25/2025.
A new Non-Final OA is follows.
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, 2, 5-11, and 14-17 are rejected under 35 U.S.C. §103 as being unpatentable over Stabel et al. (US 5,731,483) in view of Ramamurthy et al. (US 2019/0177626 A1) and further in view of Khan et al. (WO95/09902 A1).
Stabel teaches converting waste plastics into hydrocarbon products by liquefying waste plastics, feeding the liquefied plastic directly to a pyrolysis reactor to produce a pyrolysis effluent comprising gaseous and liquid hydrocarbon products, separating the pyrolysis products into gaseous and liquid fractions, and feeding the recovered liquid hydrocarbon fraction directly to a steam cracker for production of light olefins without hydroprocessing of the cracker feed (see, e.g., col. 2, lines 55–67; col. 5, lines 1–35; Figs. 1–3).
However, Stabel does not teach (1) feeding pyrolysis gas to the cracker facility downstream of the cracker furnace, (2) recovering heat from the pyrolysis effluent, pyrolysis gas, and/or pyrolysis oil by a heat-transfer medium for transfer to a process for making or processing a chemical or energy, (3) recovering CO₂ from pyrolysis flue gas and/or pyrolysis gas, or (4) integrating the pyrolysis facility with the cracker facility to reduce the global warming potential of olefin production.
Ramamurthy teaches an integrated waste-plastic pyrolysis and steam-cracking process in which pyrolysis gas and pyrolysis oil are routed to downstream cracking operations, including feeding pyrolysis-derived gas downstream of the cracker furnace, integrating the pyrolysis facility with the cracker facility, and producing high-value chemical products including ethylene, propylene, butadiene, aromatics, hydrogen, pyrolysis gasoline, pyrolysis gas, and pyrolysis oil (see ¶¶ [0040]–[0048], [0064]–[0073], [0089]–[0098]; Figs. 1, 2, and 10).
Khan teaches recovering CO₂ from plastic-derived process gases by conventional gas purification before downstream utilization of the gas streams, thereby reducing emissions associated with the integrated process (see Summary; step (4); Example 1).
Regarding claims 1 and 10, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the waste-plastic pyrolysis process of Stabel by incorporating the integrated cracking configuration taught by Ramamurthy together with the CO₂ recovery techniques taught by Khan because such modifications improve utilization of plastic-derived hydrocarbons, reduce greenhouse gas emissions, improve overall process efficiency, and represent the predictable application of known process integration and gas purification techniques.
Regarding claims 2, 5, 6, 8–11, 14–17, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the combined process as recited because Ramamurthy teaches routing pyrolysis gas to downstream cracking operations, integrated pyrolysis/cracking facilities, and production of ethylene, propylene, butadiene, aromatics, hydrogen, pyrolysis gasoline, pyrolysis gas, and pyrolysis oil (see ¶¶ [0040]–[0048], [0064]–[0073], [0089]–[0098]), while Khan teaches recovery of CO₂ from plastic-derived gas streams (p. 5, lines. 8–23; Example 1). The resulting reduction in GWP constitutes an expected result achieved by routine optimization of known process variables.
Regarding claim 7, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the integrated process such that the pyrolysis facility and cracking facility are located within 10 miles of one another because selecting plant spacing sufficient to reduce transportation costs, improve heat integration, and minimize energy losses constitutes routine engineering optimization and design choice.
Claims 3 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over references as applied to claims 1 and 10 above, and further in view of Bitting et al. (US 2020/0369965 A1)
Stabel does not teach using at least a portion of a demethanizer overhead stream as fuel in the cracker facility and/or pyrolysis facility.
Bitting teaches an integrated plastic-pyrolysis/steam-cracking process employing conventional cracked-gas separation including a demethanizer and teaches routing methane-rich demethanizer overhead to plant fuel gas for firing process heaters and furnaces (see, e.g., ¶¶ [00010], [0180]–[0188], [0215]–[0222], Fig. 10).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the combined process of Stabel by utilizing at least a portion of the demethanizer overhead stream as fuel because methane-containing refinery off-gas streams are conventionally used as plant fuel gas to improve energy efficiency and reduce external fuel consumption.
Claims 4 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over references as applied to claims 1 and 10 above, and further in view of Stankevitch (US 6,534,689 B1)
Stabel does not teach a heat-transfer medium deriving heat from the pyrolysis process and transferring that heat to waste plastic feedstock.
Stankevitch teaches employing a circulating solid heat-transfer medium that is heated during the pyrolysis process and recycled to transfer thermal energy to incoming waste plastics, thereby improving reactor heat transfer and reducing external heating requirements (see, e.g., col. 1, ll. 28–67; col. 5, ll. 18–65; Figs. 1–3).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to incorporate the circulating heat-transfer medium of Stankevitch into the combined process because recycling recovered thermal energy to incoming waste plastic feedstock improves pyrolysis efficiency and represents a well-known engineering technique.
Claims 18-20 are rejected under 35 U.S.C. §103 as being unpatentable over Stabel et al. in view of Khan et al.
Stabel teaches producing olefins from non-hydroprocessed plastic-derived hydrocarbon feeds by pyrolysis followed by steam cracking (see col. 2, lines. 55–67; col. 5, lines. 1–35).
Stabel, however, does not expressly teach recovering olefins at a global warming potential of less than 1.45 kg CO₂ per kg olefins.
Khan teaches recovery and removal of CO₂ from plastic-derived gas streams using conventional gas purification technology prior to downstream use (see p. 5, lines. 8–23; Example 1).
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 combined process so as to recover olefins at a reduced GWP, including less than 1.45 kg CO₂/kg olefins, because carbon intensity is a recognized result-effective variable, and optimization of operating conditions, process integration, and CO₂ recovery would have predictably reduced CO₂ emissions per unit olefin produced. Claims 19 and 20 fall with claim 18 because the cracking facility and co-location of the pyrolysis facility represent conventional integrated plant configurations.
Conclusion
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/TAM M NGUYEN/Primary Examiner, Art Unit 1771
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