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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 28 May 2026 has been entered.
Claims 1-16, 18-21, and 28 are pending.
The previous rejections have been updated as necessitated by amendments to the claims.
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 1-11 and 28 are rejected under 35 U.S.C. 103 as being unpatentable over Kirkwood (US 5,364,995) in view of Kaminsky (Feedstock recycling of polymers by pyrolysis in a fluidized bed).
Regarding claims 1-5, 7-9, and 28, Kirkwood teaches steam cracking a mixture of naphtha (predominantly c5-12, which lies within the claimed range of predominantly C5-C22) with wax obtained from pyrolysis of high density and low density polyethylene (column 9, lines 1-50 and column 8, lines 20-40). Kirkwood teaches steam to hydrocarbon ratios of 0.2-1:1 (column 5, lines 20-30), which encompasses the claimed range. Kirkwood teaches that the hydrogenation step is optional (column 6, lines 8-15). In this regard, Kirkwood includes embodiments with or without hydrotreatment.
Kirkwood teaches the wax fed to the steam cracker is obtained from fluidized pyrolysis of HDPE and LDPE at temperatures of 300-690°C (column 3, lines 20-68 and column 2, lines 7-15 and column 8, lines 20-40).
It is expected that the Kirkwood wax feed would have the same or similar C24+ and C12+ content and boiling point curve as claimed, since the instant specification teaches the same pyrolysis of HDPE or LDPE at the same temperatures as Kirkwood [0042], [0114], [0139].
Kirkwood teaches pyrolysis of high density polyethylene at temperatures of 500°C (see example no 1 in table 1) to create wax feedstock to be combined with naphtha and fed to radiant section of the steam cracker. Examiner notes that the instant specification similarly teaches creation of the recycle content oil by pyrolysis of high density polyethylene [0130], [0131] at temperatures of above 325°C, above 350°C, above 375°C, above 400°C, above 425°C, above 450°C, above 475°C above 500°C [0139].
Therefore, it is expected that the Kirkwood wax feed obtained from pyrolysis of high density polyethylene at a temperature of 500°C would have the same or similar properties, including being liquid at 25°C and 1 atm, since it is formed by the same pyrolysis of high density polyethylene at the same temperature as identified in the applicant’s instant specification.
Alternatively, it would have been obvious to the person having ordinary skill in the art that the Kirkwood feed obtained from pyrolysis of high density polyethylene at a temperature of 500°C would have the same or similar properties, including being liquid at 25°C and 1 atm, since it is formed by the same pyrolysis of high density polyethylene at the same temperature as identified in the applicant’s instant specification.
Kirkwood temperature range of up to 690˚C is slightly outside the claimed range of 750-1100˚C.
However, Kaminsky teaches that various waste plastic pyrolysis temperature ranges are operable, including 500-650˚C, 650-800˚C, 600-800˚C, 600-900˚C (pages 1046-1047). Kaminsky similarly teaches that waxes and oils produced from pyrolysis may be fed to the steam cracker (page 1046). Kaminsky teaches that higher temperature ranges result in optimization of olefin range products (page 1046).
Therefore, it would have been obvious to the person having ordinary skill in the art to have adjusted the temperature range of the pyrolysis zone, in order to achieve the desired product profile. Examiner notes that the person having ordinary skill in the art may be motivated to use higher temperature ranges, for the benefit of producing olefin products in addition to the oil and wax range products that are fed to steam crackers. Examiner notes that Kaminsky teaches that such higher temperature ranges are workable, thus, the person having ordinary skill in the art would have a reasonable expectation of success. It is further expected that the same aromatic content would be achieved, since the prior art teaches overlapping operation conditions.
Regarding claim 6, Kirkwood teaches 5-50% wax (waste plastic derived pyrolysis oil feed) (column 3, lines 20-35).
Regarding claims 10-11, Kirkwood teaches introduction of the steam into the convective bank with the naphtha feed, and then combining the heated mixture with the wax feed prior to radiative bank (see figure 4). Examiner additionally notes that the order of mixing is prima facie obvious in the absence of new or unexpected results.
Claims 12-16, and 18-21 are rejected under 35 U.S.C. 103 as being unpatentable over Kirkwood (US 5,364,995) in view of Kaminsky (Feedstock recycling of polymers by pyrolysis in a fluidized bed) as applied to claim 1 above, and further in view of Rubin (US 5,523,502).
Regarding claims 12-16, and 18-21, the previous combination teaches the limitations of claims 1-5 and 7-11 as discussed above. Examiner notes that as discussed with respect to the claims above, it is expected that the wax of the previous combination would have the same or similar C13-22, C4-12, and aromatic contents and additional properties as claimed, since the previous combination teaches the same pyrolysis of waste plastic to form the wax feeds.
Kirkwood does not explicitly disclose C2-4 feed to the steam cracker.
However, Rubin teaches that non-recycle feedstocks to steam cracking include gas oils, naphtha, propane, ethane or mixtures thereof (column 4, lines 1-33).
Therefore, it would have been obvious to the person having ordinary skill in the art to have used a stream of at least 60 wt % non-recycled propane or ethane or a mixture thereof in place of or in combination with the naphtha feed of the previous combination, since Rubin teaches that these are also conventional feeds to steam cracking furnaces to produce olefin products.
Response to Arguments
Applicant’s arguments have been fully considered and are addressed by the updated rejections as necessitated by amendments to the claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Stankevitch (US 2003/0047437) – teaches pyrolysis of waste plastic at temperatures of 400-900˚C [0048]
Evans (US 5,216,149) – teaches various temperatures can be utilized for pyrolysis of plastic materials (see table 1)
Narayanaswamy (US 2014/0228606) – teaches sending naphtha from pyrolysis of waste plastic to steam cracking [0003-0004], plastic pyrolysis temperatures selected in the range of 470-730˚C to obtain the desired product profile [0077-0083]
Madar (US 6,165,349) – teaches plastic pyrolysis at temperatures of 700˚C (abstract)
Stabel (US 5,731,483) – previously relied on, teaches steam cracking of waste plastic derived pyrolysis oils
Ward (US 2016/0362609) – previously relied on, teaches replacing at least a portion of steam cracker feeds with products of waste plastic pyrolysis [0010]. Such mixtures of feedstock improves the economic situation for steam crackers [0010].
EP 687692 – teaches liquid wax product derived from pyrolysis of plastic sent to steam cracking (page 5, lines 49-54, see figure).
US Application 16881030 and 17755330 – drawn to a similar process for steam cracking of recycle pyrolysis oil. It is noted that if the claims are amended, double patenting issues may arise.
US 5,656,150 – teaches steam cracking furnace with convection section, radiant section, and crossover section
US 2016/0264885 – teaches pyrolysis of waste plastics followed by steam cracking
US 2019/0177626 - teaches pyrolysis of waste plastics to make steam cracker feedstocks
US 2018/0002609 – teaches plastic pyrolysis
US 2009/0050530 – teaches steam cracking with addition of hydrocarbons, steam, and diluent at different locations in the furnace
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHELLE STEIN whose telephone number is (571)270-1680. The examiner can normally be reached Monday-Friday 8:30 AM-5:00 PM.
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 571-272-6381. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/MICHELLE STEIN/Primary Examiner, Art Unit 1771
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