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 .
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.
Election/Restrictions
As set forth in the prior Office action, claims 25, 27, and 28 stand withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 29 August 2025.
Information Disclosure Statement
The Information Disclosure Statement filed on 22 January 2026 has been received and considered by the Examiner, except with respect to the USPTO Office actions that were not included with the submission, as noted on the considered IDS.
Amendments
Applicant’s amendments to the claims filed on 22 January 2026 have been received and considered for this action. These amendments overcome the prior rejections of claims 7, 12, 13, 15, 18, and 19 under 35 USC §112(b), which are withdrawn.
The cancellation of claim 14 renders the prior rejection of this claim under 35 USC § 112(d) moot.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1, 5-8, 10, 13, 15, 18-20, and 22-24 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites “said mixed waste plastic” in line 8 and “said vitrification materials” in line 9. There is insufficient antecedent basis for these limitations. While claim 1 refers to “waste plastic feedstock” and “waste plastic” it is unclear what composition in particular is referenced by “said mixed waste plastic.” Additionally, while line 8 recites “one or more vitrification materials”, it is unclear if “said vitrification materials” refers to the same materials when only one such material is present. For the purposes of further examination, “said vitrification materials” is interpreted as meaning “said one or more vitrification materials.”
Claims 5-8, 10, 13, 15, 18-20, and 22-24 each depend upon claim 1 without resolving these issues of antecedent basis and are likewise rejected.
Claim 8 recites the limitation "the heavies-depleted stream" in line 2. There is insufficient antecedent basis for this limitation in the claim as neither claim 8, nor claim 1 upon which it depends recite a heavies-depleted stream. For the purposes of further examination, claim 8 will be interpreted as depending upon claim 7 which does recite a heavies-depleted stream.
Claim 15 is rejected because it depends upon claim 14, which has been cancelled. For the purposes of further examination, claim 15 will be interpreted as if it depends upon claim 1.
Claims 20 and 22 each recites a step of “feeding a waste plastic feedstock to a partial oxidation gasifier”, but it is unclear if these steps are referencing the same feeding step recited in claim 1, “feeding a waste plastic feedstock into a partial oxidation gasifier”, or if claims 20 and 22 are requiring a separate step of feeding of a different waste plastic feedstock into a different partial oxidation gasifier. Likewise, claims 20 and 22 each recite the additional step of “partially oxidizing at least a portion of said waste plastic…to produce synthesis gas” which is already recited in claim 1; such repeat limitations should be eliminated if they are intended to be the same method step as in the base claim. For the purposes of further examination these steps are interpreted as merely repetitions of the same steps recited in claim 1.
Claims 23 and 24 depend from claim 22 and are likewise rejected.
Claim 23 also recites the limitation "said solvolysis chemical recycling facility”. There is insufficient antecedent basis for this limitation in the claim, as none of claim 23 or claims 22 or 1 upon which it depends recite a “solvolysis chemical recycling facility.” Claim 22 recites a “chemical recycling facility” and claim 1 recites a “solvolysis facility,” but it is unclear if these are the same facilities or not.
Claim Rejections - 35 USC § 103
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, 5-6, 13, 18, and 22-23 are rejected under 35 U.S.C. 103 as being unpatentable over Khan et al. (US 5,656,042 A) in view of Cudmore (US 4,578,502 A).
Regarding claim 1, Khan teaches a method of producing synthesis gas comprising: feeding a waste plastic feedstock into a partial oxidation gasifier (scrap plastic materials which are used as feed…to a partial oxidation gas generator; column 2, lines 8-9), said waste plastic feedstock comprising waste plastic (polyethylene in a mixture comprising several types of plastics found in the household; column 7, lines 33-36) and one or more vitrification materials directly derived from said mixed waste plastic (associated inorganic matter [column 1, line 50], which include vitrification materials such as titania, alumina, aluminum, glass and barium carbonate [column 2, lines 22-33]); and partially oxidizing said waste plastic feedstock within said partial oxidation gasifier to produce said synthesis gas (column 1, lines 60-62).
Khan also teaches that the associated inorganic matter in the plastic waste stream, such as dyes, pigments, catalysts and fillers (column 2, lines 16-34), can be incorporated into the slag (noncombustible materials in the plastic materials, and the encapsulated material will flow from the reaction zone of the gas generator as substantially inert molten slag; column 5, lines 49-52). Khan further teaches that fillers include titania, talc, clays, alumina and barium carbonate (column 2, lines 23-24), which can be considered vitrification materials. Khan does not teach at least a portion of the vitrification materials being obtained from a decanter, a reactor purge, or a distillation column bottom stream of a solvolysis facility.
However, Cudmore teaches that the solvolysis process to recycle PET leaves a distillation column bottoms stream (residue from thin film evaporator configured to collect ethylene glycol) that contains the catalysts, dyes, pigments, and fillers from the original PET waste (column 5, lines 49-58).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to add the distillation column bottoms stream taught by Cudmore to the method of modified Khan, thereby arriving at the instantly claimed invention. One of ordinary skill in the art would have been motivated to do so because Cudmore teaches that this stream contains many of the same components as those described by Khan as benefitting from being encapsulated in the inert slag generated by their process.
Regarding claim 5, modified Khan teaches the method of claim 1 where Khan teaches the partial oxidation gasifier operating in conditions that produce slag (by the aforesaid operating conditions…nontoxic slag [is produced];column 5, lines 25-27).
Regarding claim 6, modified Khan teaches the method of claim 5 where Khan teaches the slag including at least a portion of the said one or more vitrification materials derived from plastic material of said feedstock (inorganic matter in the solid carbonaceous plastic-containing material is safely captured …to produce nonhazardous slag; column 1, lines 16-19).
Regarding claim 13, modified Khan teaches the method of claim 1 where Khan teaches the feedstock to the partial oxidation gasifier includes leachable materials comprising chromium in the amount of 0.16 wt% of the feed, which falls in the instantly claimed range (ash makes up 58.3% of the feed, Table I, and Cr2O3 makes up 0.28% of the ash, Table II: 0.28% of 58.3% is 0.16%).
Regarding claim 18, modified Khan teaches the method of claim 1, where Khan also teaches that coal can be included in the feedstream (the aluminosilicate-containing material that is used as a feedstream in the process is a nonpolymeric material selected from the group of solid materials consisting of coal…; column 3, line 50-52).
Regarding claim 22, modified Khan teaches the method of claim 1, where Khan teaches a waste plastic feedstock is fed to a partial oxidation gasifier (pumpable slurry of plastics, and coal ash is reacted … by partial oxidation in a conventional free-flow noncatalytic gas generator; column 8, lines 36-40), which will necessarily occur in a partial oxidation gasification facility, said feedstock comprising a waste plastic (a mixture comprising several types of plastics that are found in the household; column 7, lines 34-35) and vitrification materials (associated inorganic matter in the plastic [column 1, line 50], as well as the added aluminosilicate-containing coal ash). Khan also teaches partially oxidizing at least a portion of said waste plastic within said partial oxidation gasifier to produce synthesis gas and forming within said partial oxidation gasifier a slag (synthesis gas is produced along with about 5 tons of nonleachable slag; column 7, lines 41-42) comprising at least a portion of said one or more vitrification materials (inorganic matter in the solid carbonaceous plastic-containing material is safely captured …to produce nonhazardous slag; column 1, lines 16-19).
As analyzed for claim 1, Cudmore teaches that the solvolysis process to recycle PET leaves a distillation column bottoms stream (residue from thin film evaporator configured to collect ethylene glycol) that contains the catalysts, dyes, pigments, and fillers from the original PET waste; column 5, lines 49-58), and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to add this stream which is enriched in one or more vitrification materials obtained from a chemical recycling facility to the waste plastic feedstock being fed to the partial oxidation gasifier, thereby arriving at the instantly claimed invention. One of ordinary skill in the art would have been motivated to do so because Cudmore teaches that this stream contains many of the same components as that described by Khan as benefitting from being encapsulated in the inert slag generated by their process.
Regarding claim 23, modified Khan teaches the method of claim 22, where Cudmore teaches the process occurring in the chemical facility is methanoloysis or hydrolysis of PET where the monomers resulting from the depolymerization are repolymerized to fresh PET (abstract and column 2, lines 16-21), making such a facility a methanolysis or hydrolysis chemical recycling facility.
Claims 7-8, 10, 15, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Khan et al. (US 5,656,042 A) in view of Cudmore (US 4,578,502 A), as applied to claim 1 above, and further in view of Bai (US 2013/0240647 A1).
Regarding claim 7, modified Khan teaches the method of claim 1, but Khan does not teach sorting a mixed plastic waste stream into a heavies-enriched stream and a heavies-depleted stream.
However, Bai teaches methods of sorting mixed waste streams ([0008]), including for improved performance during gasification applications related to the conversion of these streams into chemical and fuel feedstocks ([0003]), and that these mixed waste streams include mixed plastic waste (Types of MSW components include, but are not limited to, plastics, including soft plastics and hard plastics (e.g., #1 to #7 plastics and other polymers such as Acrylonitrile-butadiene-styrene (ABS), Polyamide (also called nylon, PA), Poly(butylene terephthalate)--PBT); [0033]).
Bai further teaches sorting the mixed plastic waste into a heavies-enriched stream (244-246, Fig. 2, which comprises heavy materials such as ferrous and non-ferrous metals, as defined in the instant specification [0135]) and a heavies-depleted stream (235, Fig. 2), where a portion of one or more vitrification materials are included in the heavies-depleted stream (the [heavies-depleted] waste stream can be conveyed from the secondary shredder 235 to an additional density separator … the additional density separator can be used to ensure the waste stream is substantially free from metals, glass, and/or any other material that can, for example, have adverse effects on the material classification subsystem 220; [0053]); the materials recited by Bai (e.g., glass) are vitrification materials that are still present in the heavies-depleted stream.
Therefore it would have been obvious to one of ordinary skill in the art to modify the method of Khan to first separate the mixed plastic waste into a heavies-enriched stream and a heavies depleted stream, where at least a portion of the vitrification materials are included in the heavies-depleted stream, as taught by Bai. One of ordinary skill in the art would have been motivated to do so because such sorting can remove non-processable waste, prohibitive items, and marketable recycles from the waste stream and improve its performance during gasification, as taught by Bai ([0020] and [0003]).
Regarding claim 8, which is being interpreted as depending upon claim 7 (see Claim Rejections – 35 USC § 112), modified Khan teaches the method of claim 7, where Bai teaches a density separation process on the heavies-depleted stream forms a stream enriched in vitrification materials (the waste stream can be conveyed from the secondary shredder 235 to an additional density separator … the additional density separator can be used to ensure the waste stream is substantially free from metals, glass, and/or any other material that can, for example, have adverse effects on the material classification subsystem 220; [0053]).
Khan further teaches the non-combustible materials from the plastic waste stream, which includes materials separated by the additional density separator of Bai such as glass, can be captured in the slag of the partial oxidation gasifier (column 5, lines 49-52), and later sold as a useful byproduct (column 5, lines 57-58).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use at least a portion of the one or more vitrification materials isolated from the heavies-depleted stream of Bai into the partial oxidation gasifier of Khan. One of ordinary skill would have been motivated to do so because it would allow them to convert waste material into a salable and useful product, as taught by Khan.
Regarding claim 10, modified Khan teaches the method of claim 1 where Bai teaches the mixed plastic feedstock being obtained by a separation of mixed plastic waste including a density separation process that produces a high density stream and a low density stream (materials with a density below a predetermined threshold pass to the material classification subsystem and material with a density above the predetermined threshold pass to a secondary subsystem [0043]), where the low density stream contains the plastic and fibers ([0050]). Bai further teaches that the plastics will have densities up to about 87 pounds per cubic foot (1.39 g/cc; [0028]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a mixed plastic feedstock in the method of modified Khan that was obtained by a separation of mixed plastic waste including a density separation process that produces a high density stream having a density above 1.39 g/cc and a low density stream having a density less than the density of the high density stream.
One of ordinary skill in the art would have been motivated to do so because Bai teaches that plastics have densities below this threshold, and will therefore be funneled to the low-density stream, while ferrous metals, non-ferrous metals, glass, dirt, and/or the like, which will have densities above this threshold, can be separated by such a density separation procedure ([0050]).
Regarding claim 15, which is being interpreted as depending upon claim 1 and not cancelled claim 14, modified Khan teaches the method of claim 1, but Khan does not teach sorting a mixed plastic waste stream into a heavies-enriched stream and a heavies-depleted stream, the heavies-enriched stream comprising one or more of ferrous metals, non-ferrous metal, glass, and dirt.
However, Bai teaches methods of sorting mixed waste streams ([0008]), including for improved performance during gasification applications related to the conversion of these streams into chemical and fuel feedstocks ([0003]), and that these mixed waste streams include mixed plastic waste (Types of MSW components include, but are not limited to, plastics, including soft plastics and hard plastics (e.g., #1 to #7 plastics and other polymers such as Acrylonitrile-butadiene-styrene (ABS), Polyamide (also called nylon, PA), Poly(butylene terephthalate)--PBT); [0033]).
Bai further teaches sorting the mixed plastic waste into a heavies-enriched stream (244-246, Fig. 2) and a heavies-depleted stream (235, Fig. 2), where the heavies-enriched stream comprises ferrous metal and non-ferrous metal (244, 245; Fig. 2).
Therefore it would have been obvious to one of ordinary skill in the art to modify the method of Khan to first separate the mixed plastic waste into a heavies-enriched stream and a heavies-depleted stream where the heavies-enriched stream comprises ferrous metal and non-ferrous metal, as taught by Bai. One of ordinary skill in the art would have been motivated to do so because such sorting can remove non-processable waste, prohibitive items, and marketable recycles from the waste stream and improve its performance during gasification, as taught by Bai ([0020] and [0003]).
Regarding claim 20, modified Khan teaches the method of claim 1, which includes feeding a waste plastic feedstock into a partial oxidation gasifier (scrap plastic materials which are used as feed…to a partial oxidation gas generator; column 2, lines 8-9), along with vitrification materials (associated inorganic matter [column 1, line 50], which include vitrification materials such as titania, alumina, aluminum, glass and barium carbonate [column 2, lines 22-33]); and partially oxidizing said at least a portion of said waste plastic feedstock within said partial oxidation gasifier to produce said synthesis gas (reacting said pumpable slurry from (1) [comprising waste plastic] … in a partial oxidation gas generator in a reducing atmosphere to produce synthesis gas; column 1, lines 60-62). Khan further teaches that the mixed plastic stream contains about a trace to about 80 wt% of inorganic components (column 2, line 33-35), or about 20 wt% to less than 100% of carbonaceous plastic-containing material.
Khan does not teach separating a waste plastic to produce a vitrification materials stream comprising one or more vitrification materials and between 4% and 50% by weight of one or more plastic materials, or feeding any of such a stream to a partial oxidation gasifier.
However, Bai teaches methods of sorting mixed waste streams ([0008]), including for improved performance during gasification applications related to the conversion of these streams into chemical and fuel feedstocks ([0003]), and that these mixed waste streams include mixed plastic waste (Types of MSW components include, but are not limited to, plastics, including soft plastics and hard plastics (e.g., #1 to #7 plastics and other polymers such as Acrylonitrile-butadiene-styrene (ABS), Polyamide (also called nylon, PA), Poly(butylene terephthalate)--PBT); [0033]). Bai further teaches separating a waste plastic to produce a vitrification materials stream (Glass, Fig. 2).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention separate the waste plastic to produce a stream of vitrification materials, as taught by Bai, and to feed at least a portions of said stream to the partial oxidation gasifier of Khan.
One of ordinary skill in the art would have been motivated to do so because such sorting can remove non-processable waste, prohibitive items, and marketable recycles from the waste stream and improve its performance during gasification, as taught by Bai ([0020] and [0003]), and because feeding the vitrification materials with plastics to the partial oxidation gasification allows for the production of a slag that encapsulates toxic components of the waste stream and which could be sold as a useful by-product (toxic elements in the inorganic matter in the solid carbonaceous plastic-containing material are captured by the noncombustible constituents in the aluminosilicate-containing material and converted into nontoxic nonleachable slag. This permits the nontoxic slag to be sold as a useful by-product; col. 5, lines 53-58), as taught by Khan.
It would have also been obvious to produce a vitrification materials stream containing one or more plastic materials at 4-50 wt%. One of ordinary skill would have been motivated to do so because this stream would be fed to the partial oxidation gasifier which Khan teaches should be supplied with a stream containing from about 20 wt% to less than 100 wt% of solid carbonaceous plastic-containing material, and such material could be supplied from either the waste plastic feedstock or the vitrification materials stream with equivalent results, as both streams end up together in the gasifier.
It is further noted that the amount of plastic in the vitrification materials stream may come from either inefficient separation in the method taught by Bai, or from the purposeful addition of plastic materials back into this stream. As the vitrification materials are ultimately mixed with a waste plastic feedstock, it would have been obvious to optimize the efficiency of the separation by routine experimentation (Bai, [0052]) to afford the desired compositions of separated streams with resources put into the separation, including by allowing some plastics to pass through into the vitrification materials stream at an amount of 4 wt% to 50 wt%. It would have also been obvious to mix plastic back into the vitrification material stream to afford the desired level of plastic in the mix being fed to the partial oxidation gasifier, from about 20 wt% to less than 100 wt% of solid carbonaceous plastic-containing material, as taught by Khan.
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01). Therefore, the claimed ranges of plastic materials in the vitrification stream merely represent an obvious variant and/or routine optimization of the cited prior art.
Claims 19 is rejected under 35 U.S.C. 103 as being unpatentable over Khan et al. (US 5,656,042 A) in view of Cudmore (US 4,578,502 A), as applied to claim 1 above, and further in view of Bai (US 2013/0240647 A1) and National Geographic (“Plastic Recycling Guide”, Strange Days on Planet Earth. Retrieved from the Internet: <http://www-tc.pbs.org/strangedays/pdf/StrangeDaysSmartPlasticsGuide.pdf>, Archived 2015-02-13).
Regarding claim 19, modified Khan teaches the method of claim 1, which comprises feeding a plastic stream (scrap plastic materials which are used as feed… column 2, lines 8) and one or more vitrification materials (associated inorganic matter [column 1, line 50], which include vitrification materials such as titania, alumina, aluminum, glass and barium carbonate [column 2, lines 22-33]) to a partial oxidation gasifier (to a partial oxidation gas generator; column 2, lines 9) and partially oxidizing the plastic within said partial oxidation gasifier to produce said synthesis gas (column 1, lines 60-62).
Khan does not teach separating a mixed plastic waste into a polyethylene terephthalate (PET)-enriched plastic stream and a polyolefin-enriched PET-depleted plastic stream.
However, Bai teaches the separation of a mixed plastic into various streams (Fig. 2 and 3) including a PET-enriched plastic stream (hard plastics ([0028]; 360B Fig. 3) and a polyolefin-enriched PET-depleted stream (soft plastics ([0037]; 360D, Fig. 3) and a heavies stream comprising one or more vitrification materials (Glass; 360A Fig. 3).
Furthermore, National Geographic teaches that PET is one the most easily recycled plastics and that it can be recycled into new bottles or into polyester fibers (Plastic #1), while low density polyolefins (LDPE and PP) are not usually or easily recycled (Plastic #4 and Plastic #5).
Therefore, it would have been obvious to one of ordinary skill in the art to modify the method of Khan to first separate out the more easily recycled PET plastics into a PET-enriched stream according to the method of Bai, and to feed the polyolefin-enriched PET-depleted plastic stream and one or more vitrification materials to a partial oxidation gasifier, and to partially oxidize at least a portion of one or more polyolefins contained within said partial oxidation gasifier to produce synthesis gas, as taught by Khan. One of ordinary skill in the art would have been motivated to do so because this would allow them to funnel the more recyclable PET material to a separate recycling process while using at least part of the less-recyclable polyolefin-enriched PET-depleted stream to generate synthesis gas, a chemical feedstock.
Claim 24 is rejected under 35 U.S.C. 103 as being unpatentable over Khan et al. (US 5,656,042 A) in view of Cudmore (US 4,578,502 A), as applied to claim 23 above, and further in view of Andrados et al. (Waste Manag. 2012, 32, 826-832).
Regarding claim 24, modified Khan teaches the method of claim 23, but does not teach any of the vitrification material stream being obtained from pyrolyzing a waste plastic in a pyrolysis reactor of a pyrolysis facility.
However, Andrados is also directed to the recycling of plastic waste streams to chemical products (abstract) and Andrados further teaches that the solids residues generated by pyrolysis of waste plastic in a pyrolysis reactor of a pyrolysis facility include ceramics and glass that would most likely be placed in a landfill (p. 831, col. 2, ¶ 1). Khan teaches that similar aluminosilicate materials can be used as vitrification materials (aluminosilicate clay materials; col. 4, lines 62-64) to produce a slag that encapsulates toxic components of the waste stream and which could be sold as a useful by-product (toxic elements in the inorganic matter in the solid carbonaceous plastic-containing material are captured by the noncombustible constituents in the aluminosilicate-containing material and converted into nontoxic nonleachable slag. This permits the nontoxic slag to be sold as a useful by-product; col. 5, lines 53-58).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to obtain at least a part of the vitrification material stream used in the method of modified Khan from pyrolyzing waste plastic in a pyrolysis reactor of a pyrolysis facility. One of ordinary skill in the art would have been motivated to do so because Khan teaches that similar aluminosilicate-containing materials can provide a source of vitrification materials that can be converted to useful by-products, and Andrados teaches that the ceramics generated in the pyrolysis reactor from a waste plastic pyrolysis facility may otherwise be destined for a landfill.
Response to Arguments
Applicant’s arguments, see page 7 of the reply filed 22 January 2026, with respect to the rejections of claims 7, 12, 13, 15, 18, and 19 under 35 USC 112(b) have been fully considered and are persuasive. The prior rejections of these claims under 35 USC 112(b) have been withdrawn.
Applicant's arguments, page 7, with respect to the rejections of claims 20, 22, and 23 under 35 USC 112(b) have been fully considered but they are not persuasive. The amendments to these claims did not resolve all the issues of duplicate limitations that rendered the claims indefinite, nor did the amendments clarify all the antecedent bases. These rejections are maintained, as analyzed above.
Applicant’s arguments, page 8, with respect to the rejection of claims 1, 5-8, 10, 13-15, 18-20, and 22 under 35 USC § 103 over Khan in view of Bai and National Geographic have been fully considered and are persuasive in that these references alone do not teach all the features of amended claim 1. The prior rejections of these claims have been withdrawn.
However, Applicant’s arguments, page 9, that the combination of Khan and Cudmore does not disclose or suggest the invention set forth in amended claim 1 are not persuasive.
Applicant provides two arguments against combining Khan and Cudmore. First, in response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
Applicant asserts that because neither Khan nor Cudmore suggest feeding a distillation column bottoms stream, in particular, to a gasifier feedstock that such a combination would only be arrived at through hindsight reasoning. However, in the instant case, the contents of the bottom stream taught by Cudmore (catalysts, dyes, pigments, and fillers; col. 55-56) are identical to components of the inorganic matter in the method of Khan (sol. 2, lines 22-30), and which Khan teaches it is beneficial to encapsulate in the slag produced by their method (col. 5, lines 52-58). Therefore it would have been obvious to one of ordinary skill in the art to seek to encapsulate the residues taught by Cudmore in such a slag according to the method of Khan.
Applicant additionally argues that Cudmore teaches away from the combination with Khan because they teach that one portion of the column bottoms are recycled back to the tower and another portion are incinerated.
It is first noted that using the “distillation column bottoms” in the method of Khan would not require removing the recycle stream, and would only involve using the residue stream destined for incineration (51 in Fig. 1 and col. 5, line 55 of Cudmore). Furthermore, incineration of a such products would generally be considered an option of last resort that has drawbacks which would be recognized by one of ordinary skill in the art and which have been identified by Khan: “With the presence of varying amounts of incombustible inorganic matter compounded in the plastic as fillers, catalysts, pigments and reinforcing agents, recovery of the plastic material is generally impractical. Further, complete combustion can release toxic-noxious components including volatile metals and hydrogen halides” (col. 2, lines 16-22, emphasis added). Therefore, the suggestion to route to an incinerator by Cudmore cannot be considered a teaching away from a method that avoids incineration, and the concomitant release of toxic-noxious components, in favor of producing a non-toxic and sellable by-product, as taught by Khan.
Applicant’s arguments, see pages 9-10, with respect to the rejection of claim 24 under 35 USC § 103 have been fully considered and are persuasive in that none of the references previously applied suggest pyrolyzing waste plastic, as required by amended claim 24. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground of rejection is made over Khan et al. (US 5,656,042 A) in view of Cudmore (US 4,578,502 A) and Andrados et al. (Waste Manag. 2012, 32, 826-832), as analyzed above.
Conclusion
Applicant's amendment necessitated the new grounds 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 Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm.
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/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/SALLY A MERKLING/SPE, Art Unit 1738