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 .
The amendments filed 2/13/26 overcome the objection to the specification and the rejections set forth under 35 USC 112(b) in the office action mailed 11/14/25. The amendments do not overcome the rejections set forth under 35 USC 103, which are maintained below, except for the rejection of claim 3 over Huang.
Claim Rejections - 35 USC § 102
Claims 1, 6-7, and 12 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Huang (Huang, J., Veksha, A., Chan, W.P., Lisak, G., “Support effects in thermocatalytic pyrolysis reforming of polyethylene over impregnated Ni catalysts, Applied Catalysis A, General, 2021, 622, 118222).
In Section 2.3 and Figure 1 (pages 2-3 of the reference) Huang discloses the pyrolysis and catalytic steam reforming of low-density polyethylene (LDPE), which is a thermoplastic as recited in claim 1. Huang discloses heating the LDPE in a pyrolysis reactor, as in the first step of claim 1, and in a heated steam reformer, as in the second step of claim 1; it is noted that claim 1 does not require that the first and second steps be carried out in the same reactor as long as they both occur during the heating of the thermoplastic. The products are then passed through condensation and drying units and collected in gas bags. In Section 3.3 and Figure 5 (pages 5-6) Huang indicates that the gas mixture produced by steam reforming includes methane and ethane, which are a hydrocarbon fuel as recited in claim 1, as well as various gaseous byproducts. While Huang does not explicitly teach that the pyrolysis step produces molecules including at least one olefin having at least one terminal carbon-carbon bond, the chemical equations provided by applicant in paragraph 21 of the specification (in particular the first three equations in the paragraph) provide evidence that these products are formed during the decomposition of polyethylene. Claim 1 is therefore anticipated by Huang.
LDPE is a polyethylene, as recited in claim 6. The pyrolysis step of Huang is carried out at 773.15 K (500° C), within the range recited in claim 7. Huang discloses in section 2.3 nitrogen is introduces as a carrier gas and that the bed in the reforming reactor is heated under nitrogen, implying that the reaction is carried out in an air-free container, as recited in claim 12.
In light of the above, claims 1, 3, 6-7, and 12 are anticipated by Huang.
Claims 1 and 6-8 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kaminsky (Kaminsky, W., Schmidt, H., Simon, C.M., “Recycling of mixed plastics by pyrolysis in a fluidized bed”, Macromol. Symp. 2000, 152, 191-199).
On page 194 Kaminsky discloses a method and apparatus where a plastic input material is heated in a pyrolysis reactor in the presence of steam, as in claim 1. In Table 3 on page 197, as well as the “Results and Discussion” section of claims 196 and 198, Kaminsky discloses that the products of the method include aliphatic and aromatic hydrocarbons as part of an oil fraction, where the aliphatic hydrocarbons include alkenes and alkanes, the oil fraction therefore meeting the limitations of the hydrocarbon fuel of claim 1, and the products also include methane, ethane, and butane gases, also meeting the limitations of the hydrocarbon fuel of claim 1. Kaminsky does not explicitly disclose that the thermoplastic decomposes into molecules comprising at least one olefin having at least one terminal carbon-carbon double bond and then reacts with steam to consume the terminal double bond, but since Kaminsky discloses heating plastics in the presence of steam, as recited in the claim, and the equations disclosed in paragraph 21 of the current specification provide evidence that the claimed reactions occur when thermoplastics decompose in the presence of steam. Claim 1 is therefore anticipated by Kaminsky.
On page 194 Kaminsky discloses that the input material comprises polyethylene, polypropylene, and polystyrene, as recited in claim 6. Examples V1 through V7 on page 197 disclose performing the heating at a temperature within the range recited in claim 7, and Examples V2 through V7 use a temperature within the range recited in claim 8.
In light of the above, claims 1 and 6-8 are anticipated by Kaminsky.
Claim Rejections - 35 USC § 103
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Huang.
The discussion of Huang in paragraph 3 above is incorporated here by reference. Huang discloses a process meeting the limitations of claim 1, and where the process is carried out in a nitrogen atmosphere. Huang does not specifically disclose carrying out the process at atmospheric pressure. However, when introducing the nitrogen into the reactor, one of ordinary skill in the art would have to select some pressure at which to carry out the process, and "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). It therefore would have been within the scope of ordinary skill in the art to optimize the pressure at which the process is carried out, arriving at the atmospheric pressure recited in claim 13, noting that Huang does not provide any indication that the reaction requires particularly high or low pressure.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Huang in view of Al-Qahtani (U.S. PG Pub. No. 2018/0298292).
The discussion of Huang in paragraph 3 above is incorporated here by reference. Huang discloses a method meeting the limitations of claim 1, and in Tables 4 and 5 discloses that the process produces a gas mixture comprising syngas, methane, and other light hydrocarbons. Huang does not disclose isolating an olefin-free methane product.
Al-Qahtani, in paragraph 7, discloses a method of separating methane and light hydrocarbons from syngas, and then separating at least a portion of the methane from the light hydrocarbons. The separated methane constitutes an olefin-free hydrocarbon fuel product, as recited in claim 2. Passing the gaseous product mixture of Huang to the apparatus of Al-Qahtani, and performing the process of Al-Qahtani, therefore meets the limitations of claim 2.
It would have been obvious to one of ordinary skill in the art to pass Passing the gaseous product mixture of Huang to the apparatus of Al-Qahtani, and to the process of Al-Qahtani on the gaseous product mixture, since Al-Qahtani teaches that the light hydrocarbons are desirable products (paragraph 4) and the methane can be recycled.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Huang in view of Hsing (U.S. Pat. No. 5,362,380).
The discussion of Huang in paragraph 3 above is incorporated here by reference. Huang discloses a method meeting the limitations of claim 1. In section 3.4 Huang discloses and discusses coke formation on the steam reforming catalysts. Huang does not further disclose a step of converting this coke to hydrogen and carbon monoxide by further steam reforming.
Hsing, in column 1 lines 10-11, discloses steam decoking of a catalyst. From column 1 line 66 through column 2 line 6, column 3 lines 27-30, and column 3 line 67 through column 4 line 31, Hsing discloses contacting a spent catalyst having coke deposited thereupon with steam, forming a gaseous stream comprising hydrogen and carbon monoxide, as recited in claim 4. Performing steam reformation on the spent catalyst of Huang therefore meets the limitations of claim 4.
It would have been obvious to one of ordinary skill in the art to perform steam reformation on the spent catalyst produced in the process of Huang, as taught by Hsing, in order to convert the coke into commercially useful hydrogen while also partially regenerating the catalyst.
Claims 11 and 14 is rejected under 35 U.S.C. 103 as being unpatentable over Huang in view of Jewell (U.S. Pat. No. 2014/0086818).
The discussion of Huang in paragraph 3 above is incorporated here by reference. Huang discloses a method meeting the limitations of claim 1, and discloses in Figure 4 that the stream reforming produces a gas stream comprising hydrogen, carbon monoxide, carbon dioxide, as well as methane. Huang does not disclose passing at least one of the byproducts (hydrogen, carbon monoxide, or carbon dioxide) through a scrubber.
Jewell, in Figure 2 and paragraphs 41-43, discloses a method of treating a crude syngas, where the syngas is first passed through a membrane and then passed to a scrubber to produce a purified hydrogen stream. Jewell indicates in paragraph 43 that the stream passed to the scrubber includes both hydrogen and carbon dioxide, meeting the limitations of claim 14. Passing the syngas of Huang to the apparatus and method of Jewell therefore meets the limitations of claim 14. Additionally, the isolating the purified hydrogen stream of Jewell from the syngas of Huang meets the limitations of claim 11 regarding removing excess hydrogen from the hydrocarbon fuel (methane) and byproduct (carbon monoxide, carbon dioxide).
It would have been obvious to one of ordinary skill in the art to pass the syngas of Huang to the apparatus and method of Jewell, including a step of passing at least one of the byproducts of Huang through a scrubber, in order to obtain a purified hydrogen has as other useful products noted in paragraphs 43 and 48 of Jewell.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Kaminsky in view of Liu (U.S. PG Pub. No. 2023/0085274).
The discussion of Kaminsky in paragraph 4 above is incorporated here by reference. Kaminsky discloses a method of steam pyrolysis of plastic waste meeting the limitations of claim 1, where the steam pyrolysis produces an oil fraction comprising aliphatic and aromatic hydrocarbons, and the aliphatic hydrocarbons mainly contain alkenes (olefins), while also containing some alkanes (paraffins). Kaminsky does not disclose hydrogenating this oil fraction in order to reduce the olefin content.
Liu, in paragraph 2, discloses a method of co-processing waste plastic pyrolysis oil with a biorenewable feedstock in a catalytic cracking process in order to produce a liquid hydrocarbon material suitable for use as a fuel or a blending component in a fuel. In paragraph 25 Liu discloses that the pyrolysis products include a gas phase and an oil phase, as in the pyrolysis products of Kaminsky, and teaches that the oil phase is used in the method of the reference. Liu discloses in paragraph 33 that polystyrene and polyvinyl chloride are preferably present in an amount of less than 5% by weight of the waste plastic feedstock, consistent with the teaching in the last paragraph of page 193 of Kaminsky that the feedstock was without polyvinyl chloride (PVC) and contained less than 5% by weight of styrene. Liu discloses in paragraph 40 that the pyrolysis oil can be hydrogenated in order to reduce the olefin content, meeting the limitations of claim 10. Liu also discloses in paragraph 40 that the pyrolysis oil can have an olefin content of not more than 1%. Hydrogenating the oil fraction of the pyrolysis product of Kaminsky, prior to using it as the waste plastic pyrolysis oil feedstock in the process of Liu, therefore meets the limitations of claim 10.
It would have been obvious to one of ordinary skill in the art to hydrogenate the oil fraction of Kaminsky, in order to reduce the olefin content in accordance with Liu’s teachings that the pyrolysis oil can be hydrogenated and that the olefin content can be very low, and it would have further been obvious to one of ordinary skill in the art to use the resulting oil fraction in the method of Liu, since Kaminsky teaches that it is derived from a plastic waste material within the scope of that desired by Liu.
Allowable Subject Matter
Claims 3, 5, and 9 are 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.
Claim 3 has been amended to clarify that the hydrogen and carbon monoxide are being used as a process fuel for heating the steam used in the method. This overcomes the rejection set forth under 35 USC 112(b) in the office action mailed 11/14/25, and the amended claim is interpreted as requiring a step of heating the steam with the hydrogen and carbon monoxide rather than simply reciting an intended use. While the Huang reference discussed in the above rejections discloses the formation of hydrogen and carbon monoxide, Huang does not disclose or render obvious using the hydrogen and carbon monoxide to heat the steam, and one of ordinary skill in the art would not have motivation to modify that Huang to incorporate the limitations of claim 3.
Regarding claim 5, the prior art, as exemplified by the references discussed above, does not disclose the method of claim 1 where the thermoplastic contains a biomass found thereupon, and the biomass is turned into char and then treated by steam reformation to produce hydrogen and carbon monoxide. Block (Block, C., Ephraim, A., Weiss-Hortala, E., Pham Minh, D., Nzihou, A., Vandecasteele, C., “Co-pyrogasification of Plastics and Biomass, a Review”, Waste and Biomass Valorization, 2019, 10, 483-509) discusses gasifying mixed feeds of plastic and biomass, but does disclose steam reforming of the biomass or biomass char, as opposed to the methane steam reforming disclosed on page 487 of Block.
Regarding claim 9, the prior art, as exemplified by the references discussed above, does not disclose or render obvious a further step of holding the hydrocarbon fuel and/or the byproduct at 575 to 725 K (301.85° to 451.85° C) in order to convert olefins into cyclic structures rather than terminal carbon-carbon bonds.
Response to Arguments
Applicant's arguments filed 2/13/26 have been fully considered but they are not persuasive. Regarding the rejection over Huang, applicant argues that the process of Huang takes place over two steps, a first step of heating LDPE in a pyrolysis reactor and a second step in a heated steam reformer. Applicant argues that in contrast, the currently presented claims require heating the thermoplastic and providing water in the form of steam simultaneously in a single step. Crucially, however, claim 1 does not require that the heating of the thermoplastic and the rection of the steam with the decomposition product of the thermoplastic take place in the same vessel, and does not require that the steam come into contact with the thermoplastic. A method that takes place in two separate vessels, where the heating of the thermoplastic in one vessel and the reaction of the decomposition product of the thermoplastic with steam in the other vessel, therefore meets the claim limitations. It is noted that Huang teaches in section 2.3 that steam is introduced into the reformer starting when the temperature in the pyrolysis reactor reaches 300° C, indicating that the steam reacts with early decomposition products of LDPE while the pyrolysis reactor is still being heated to its final temperature of 500° C. The examiner recommends that the claim could be distinguished over Huang by amending to require that the decomposition of the thermoplastic take place in the presence of steam, as disclosed in paragraph 28 of the current specification.
Regarding the rejection over Kaminsky, applicant argues that Kaminsky does not indicate that the heating of the thermoplastics and the introduction of steam occurs simultaneously, and that it is not clear that the steam is used for any purpose other than heating the pyrolysis chamber. However, fluidizing gases mix with product gases in fluidized bed pyrolysis reactors, steam will be present in the pyrolysis chamber at the same time the thermoplastic is heated in the chamber, and the summary section at the beginning of the reference indicates that the steam not only heats the fluidized bed but affects the product distribution (“The aim of the investigation was to yield the monomers ethene and propene. Therefore steam was used to fluidise the bed.”), and throughout the reference Kaminsky indicates that the cracking behavior when steam is used as the fluidizing gas is similar to that observed in steam crackers. The process of Kaminsky therefore involves both the heating/decomposition and reaction with steam recited in claim 1.
Conclusion
THIS ACTION IS MADE FINAL. 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.
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/JAMES C GOLOBOY/Primary Examiner, Art Unit 1771
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