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The rejections of claims 1-12 under 35 USC § 112 and under 35 USC § 103 over Gephart, Wofl, and Lehar are withdrawn by the examiner in view of the amendment filed on 6/2/2026.
Since a new Final Office Action is follows, applicant’s arguments will not be addressed.
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 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Gephart et al. (US 2015/0080624 A1) in view of Wolf et al. (US 2007/0227874 A1) and further in view of McBay (WO 2019/246369 A1).
Gephart teaches a chemical recycling process comprising providing a liquification vessel and a pyrolysis reactor, liquifying a solid waste plastic to form a liquified waste plastic, pyrolyzing the liquified waste plastic to form a pyrolysis effluent, subjecting the pyrolysis effluent to a plurality of indirect condensation stages to produce a plurality of pyrolysis oil streams, and recovering heat from the condensation section for reuse within the process, including heating waste plastic upstream of the pyrolysis reactor. (Gephart, ¶¶[0013]-[0016], [0032]-[0042], [0045]-[0053], Figs. 1-2.)
However, Gephart does not teach or suggest (1) providing a plurality of heat transfer medium (HTM) loops, (2) each HTM loop comprising a closed recirculating circuit containing its own heat transfer medium and circulating without direct fluid communication with another HTM loop, (3) employing different HTM compositions, including at least one aqueous HTM loop and at least one non-aqueous HTM loop, or (4) assigning different HTM loops to different temperature duties associated with multiple condensation stages.
Wolf teaches recovering heat from a plastic pyrolysis process through multiple heat-transfer circuits (WT1-WT5) operating at different process locations and temperature levels, thereby providing a plurality of independent heat-transfer circuits for staged heat recovery and process integration. (Wolf, ¶¶[0044]-[0049], [0060]-[0068], Fig. 3.)
However, Wolf does not expressly teach that the multiple heat-transfer circuits employ different HTM compositions, such as aqueous and non-aqueous heat-transfer media, or that separate HTM loops are specifically assigned to upstream and downstream condensation duties.
McBay teaches industrial heat-transfer systems employing multiple independent closed-loop heat-transfer circuits, wherein separate thermal-oil (non-aqueous) loops and hot-water (aqueous) loops circulate independently through their respective heat exchangers without direct fluid communication. McBay further teaches selecting different HTM compositions for different temperature ranges, wherein thermal-oil loops are used for higher-temperature heat duties and hot-water loops are used for lower-temperature heat duties. (McBay, ¶¶[0020], [0038], [0041]-[0043], [0050], Figs. 2-4.)
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 heat-recovery system of Gephart by incorporating the multiple heat-transfer circuits taught by Wolf and implementing those circuits as separate closed-loop HTM systems employing different heat-transfer media, as taught by McBay, because the use of independent thermal-oil and hot-water loops for different process temperature ranges was a known industrial heat-integration technique that predictably improves thermal efficiency, provides independent temperature control, prevents mixing of incompatible heat-transfer media, and enhances operational reliability. Furthermore, because the upstream condensation stages operate at higher temperatures than downstream condensation stages, it would have been an obvious matter of engineering optimization to assign the higher-temperature upstream condenser(s) to a non-aqueous thermal-oil loop and the lower-temperature downstream condenser(s) to an aqueous hot-water loop in accordance with McBay's teaching of selecting HTMs according to process temperature requirements. See KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007).
Regarding claims 2, 3, 12 and 13, Gephart teaches recovering heat from the condensation section and using the recovered heat to preheat feed materials, including heating waste plastic upstream of the liquification vessel and heating liquified plastic upstream of the pyrolysis reactor. (Gephart, ¶¶[0032], [0041], [0045], [0051], [0061]-[0063].)
Regarding Claims 4, 5, 14 and 15, Gephart teaches three sequential condensers that each condense a portion of the pyrolysis vapors into separate hydrocarbon fractions. (Gephart, ¶¶[0040]-[0042], [0050]-[0053].) Wolf further teaches staged heat recovery through multiple heat-transfer circuits associated with multiple condensation stages. (Wolf, ¶¶[0044]-[0049], [0060]-[0068].) Providing at least three condensation stages represents routine optimization of a known process variable.
Regarding Claims 6 and 16, Gephart teaches producing a plurality of pyrolysis oil streams through multiple condensation stages. (Gephart, ¶¶[0040]-[0042], [0050]-[0053].) However, Gephart does not teach introducing one or more recovered pyrolysis oil streams into a cracking facility. Wolf teaches conveying recovered hydrocarbon fractions into a cracking tower for further cracking of long-chain hydrocarbons into shorter hydrocarbons. (Wolf, ¶[0006]; ¶[0035].) It would have been obvious to further process one or more of Gephart's recovered pyrolysis oil streams in Wolf's cracking tower in order to increase conversion of heavier hydrocarbons into more valuable lighter hydrocarbons, thereby improving product quality and yield.
Regarding claims 7-10 and 18-20, McBay teaches using aqueous heat-transfer media (hot water) and non-aqueous heat-transfer media (thermal oil) in separate closed-loop heat-transfer systems serving different temperature ranges. (McBay, ¶¶[0020], [0038], [0041]-[0043], [0050].) Selection of thermal oil as the non-aqueous HTM satisfies the claimed non-aqueous HTM, while thermal oil operating at temperatures of at least 270°C and 300°C represents routine industrial operation for high-temperature heat recovery. Selection of thermal oil satisfies the claimed genus of oil, siloxane, molten salt, or molten metal.
Allowable Subject Matter
Claim 17 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
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.
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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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