DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Status
Claims 1-16 are cancelled. Claims 21-28 are new. Claims 17-20 are withdrawn due to an earlier restriction requirement.
Claims 21-28 are pending for examination below.
Response to Arguments
Applicant’s arguments and amendments filed 18 November 2025, with respect to the rejection(s) of claim(s) 1-16 under USC 103 over De Bruin in view of Gephart, Miller, Van der Ree, Mizuguchi, Yoshida, and Maduskar have been fully considered and are persuasive. Claims 1-16 have been cancelled. The previously cited prior art does not teach the limitation in new independent claim 21 of dividing the medium fraction and using a portion as a quench fluid. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of newly discovered prior art in view of the amendments.
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.
Claims 21, 22, 26, and 28 are rejected under 35 U.S.C. 103 as being unpatentable over De Bruin et al. (US 2023/0134669) in view of Uppili et al. (WO 2020/252228) and Maduskar et al. (US 2023/0159834).
With regard to claim 21, De Bruin teaches a method for pyrolyzing waste plastic (paragraph [0054]) comprising the following steps:
a) passing a waste plastic stream 114 to a liquefaction zone 40 (melt tank).
b) melting the waste plastic to form a liquified (molten) plastic 116 (paragraph [0272]).
c) passing the liquefied (molten) waste plastic 116 to a pyrolysis reactor (paragraph [0299]).
d) pyrolyzing to produce a pyrolysis oil product and pyrolysis heavy wax product, where the heavy wax product is defined as being different than the solid pyrolysis char and different from the pyrolysis oil (paragraphs [0299]), [0302]). The instant specification recites that the liquid pitch is distinguished from both solid coke (char) and the pyrolysis oil products (paragraph [0061]). Thus, the “pyrolysis heavy wax” of De Bruin is considered to be equivalent to the liquid pitch product claimed, absent any evidence to the contrary.
e) separating the pyrolysis oil into a pyrolysis gas fraction and a pyrolysis oil fraction (paragraph [0318]).
De Bruin further teaches the pyrolysis facility can comprise a quench tower (paragraph [0301]) and also teaches adding a solvent or other rheology agent to the liquefaction (melting) zone to reduce the viscosity of the polymer material (paragraph [0272]).
De Bruin does not explicitly teach i) separating the pyrolysis oil into a light fraction, a medium fraction, and a heavy fraction, ii) dividing the medium fraction into two portions and quenching the pyrolysis oil with a medium portion, or iii) dividing the heavy fraction into two portions and recycling a heavy portion to the melt tank.
With regard to i), Uppili teaches a method for thermal pyrolysis of polyolefins (paragraphs [0024] and [0033]) to produce an effluent comprising an oil product, where the oil product is separated and sent to a primary fractionator (paragraph [0057]) and fractionated into a naphtha range (light) fraction, a gas oil (medium) fraction, and bottoms (heavy) fraction (paragraph [0058]). Uppili further teaches the pyrolysis takes place at a temperature of 500-900°C and a residence time of 0.1 to 6 seconds (paragraph [0033]). De Bruin teaches the pyrolysis is performed on polyolefins (paragraph [0110]) at a temperature of 350 to 900°C (paragraph [0308]) and residence time of 0.1 to 10 seconds (paragraph [0310]). Thus, De Bruin and Uppili teach the same process of pyrolysis of polyolefins at overlapping temperatures and residence times, and the pyrolysis of De Bruin is expected to also produce a pyrolysis oil which can be fractionated into the fractions of Uppili.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to fractionate the product of De Bruin into a light, medium, and heavy oil as taught by Uppili, because Uppili and De Bruin teach similar pyrolysis of waste plastics to produce a pyrolysis oil at similar conditions, thus the pyrolysis oil product would be expected to be similar, and Uppili further teaches that it is known to fractionate the products from the pyrolysis of waste plastics at similar conditions into light, medium, and heavy fractions for further use (paragraph [0058]).
With regard to ii), Uppili further teaches quenching the pyrolysis effluent from the pyrolysis reactor with a portion of the gas oil stream (medium fraction) produced by the pyrolysis (paragraph [0037] and page 28, claim 18). Uppili further teaches that the gas oil is suitable for quenching because it is highly aromatic (paragraph [0037]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to divide the gas oil product (medium fraction) of De Bruin in view of Uppili into two portions and use a portion as the quench oil to cool the pyrolysis oil effluent from the pyrolysis reactor, because each of De Bruin and Uppili teaches pyrolysis of plastics to produce a pyrolysis oil product which is quenched, De Bruin is silent regarding the quench oil, and Uppili teaches that a portion of the gas oil (medium fraction) from the pyrolysis effluent is a suitable quench oil source because it is highly aromatic (paragraph [0037]).
With regard to iii), Maduskar teaches a method for pyrolysis after melting (Abstract). Maduskar further teaches separating the pyrolysis oil product in a fractionator to obtain a highest boiling (heavy) fraction (paragraph [0052]) and recycling the highest boiling or bottoms portion of the liquid effluent from the pyrolysis reactor to the plastic before extrusion (melting) to reduce the viscosity of the plastic feed to the pyrolysis (paragraph [0028]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to recycle the heavy fraction produced by De Bruin in view of Uppili to the liquefaction (melting) reactor of De Bruin, because De Bruin in view of Uppili teaches producing a heavy liquid pyrolysis oil fraction, De Bruin teaches adding a solvent or other rheology agent to the liquefaction (melting) step to reduce viscosity, and Maduskar teaches that recycling a bottoms fraction of the liquid pyrolysis oil lowers the viscosity of the plastic as desired by De Bruin (paragraph [0028]).
With regard to claim 22, De Bruin teaches extrusion of the plastics prior to entering the facility for processing, where the extrusion is performed by heating (paragraph [0146]). The extrusion is expected to partially or fully melt the plastics as claimed, because one of ordinary skill in the art understands that extrusion with heating is done to at least partially melt the plastics.
With regard to claim 26, De Bruin teaches combustion of at least a portion of the pyrolysis gas to provide heat for the pyrolysis reactor (paragraphs [0427]-[0429] and [0431]-[0432]).
With regard to claim 28, De Bruin teaches removing a halogen enriched gas stream (vapor stream) from the liquefaction zone (melting tank) 40 (paragraph [0290]).
Claims 23 and 25 are rejected under 35 U.S.C. 103 as being unpatentable over De Bruin et al. (US 2023/0134669) in view of Uppili et al. (WO 2020/252228) and Maduskar et al. (US 2023/0159834) as applied to claim 21 above, and further in view of Van der Ree et al. (US 2018/0010050).
With regard to claim 23, De Bruin in view of Uppili and Maduskar teaches the method above.
De Bruin in view of Uppili and Maduskar fails to teach controlling the temperature by keeping the temperature below a temperature at which char or coke will form in the pyrolysis reactor.
Van der Ree teaches a method for thermal cracking (pyrolysis) of waste plastics (paragraph [0020]). Van der Ree teaches that controlling the temperature of the thermal cracking (pyrolysis) by heat exchange to be no more than 20°C above the sought temperature greatly reduces or eliminates coke formation (paragraph [0065]), where the sought temperature is a maximum of 405-420°C (paragraph [0068]), which temperature range is within the temperature range of De Bruin of 350-900°C (paragraph [0308]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to control the temperature of the pyrolysis to limit coke formation as taught by Van der Ree, because each of De Bruin and Van der Ree teach producing pyrolysis oils by thermal cracking at overlapping temperatures, and Van der Ree teaches that the reduction or elimination of coke is desirable and can be accomplished by controlling the temperature to below a certain temperature (paragraph [0065]).
With regard to claim 25, De Bruin in view of Uppili and Maduskar teaches the method above.
De Bruin in view of Uppili and Maduskar fails to teach contacting the waste plastic with nitrogen to remove water before melting.
Van der Ree teaches a method for thermal cracking (pyrolysis) of waste plastics (paragraph [0020]). Van der Ree teaches that water is evaporated and drawn out in the compacter with buffer tanks (paragraph [0061]), that the buffer tanks are filled with nitrogen (paragraph [0060]), and that the compacter dries the plastic at a temperature (paragraph [0028]). Van der Ree further teaches that the use of the nitrogen prior to melting has the advantage of dispensing with continuous flushing of nitrogen during the melting and cracking stages (paragraph [0059]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to dry the waste plastic of De Bruin before melting using nitrogen, because De Bruin and Van der Ree each teach melting of waste plastics followed by pyrolysis to produce oils, and Van der Ree teaches that using the nitrogen to dry the waste plastic prior to melting has the advantage of dispensing with continuous flushing of nitrogen during the melting and cracking (pyrolysis) stages (paragraph [0059]).
Claim 24 is rejected under 35 U.S.C. 103 as being unpatentable over De Bruin et al. (US 2023/0134669) in view of Uppili et al. (WO 2020/252228) and Maduskar et al. (US 2023/0159834) as applied to claim 21 above, and further in view of Mizuguchi et al. (JP H11-106758 cited on IDS of 8/22/2024, machine translation provided herein).
With regard to claim 24, De Bruin in view of Uppili and Maduskar teaches the method above, where the liquefaction (melting) produces hydrogen chloride gas which is removed from the melting reactor (paragraph [0290]).
De Bruin in view of Uppili and Maduskar is silent regarding dividing the molten plastic, feeding the first portion to the pyrolysis reactor, and mixing the second portion with the waste plastic upstream of the melt tank.
Mizuguchi teaches melting plastic into a high temperature molten stream, dividing the stream, recycling a portion of the stream to the melting step, and passing the remaining portion to thermal decomposition (pyrolysis) (Abstract, paragraph [0007]). Mizuguchi further teaches that mixing a portion of the high temperature molten plastic with the plastic pieces rapidly melts the plastic, thus efficiently removing hydrogen chloride gas (paragraph [0014]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to divide the melted plastic of De Bruin into two portions and recycle the second portion to the melting step as claimed, because De Bruin and Mizuguchi each teach melting plastic and passing the melted plastic to pyrolysis, where the melting produces hydrogen chloride gas which is removed from the melting, and Mizuguchi teaches that recycling a portion of the melted plastic to the melting improves hydrogen chloride gas removal (paragraph [0014]).
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over De Bruin et al. (US 2023/0134669) in view of Uppili et al. (WO 2020/252228) and Maduskar et al. (US 2023/0159834) as applied to claim 21 above, and further in view of Yoshida et al. (US 3,984,288).
With regard to claim 27, De Bruin in view of Uppili and Maduskar teaches the method above.
De Bruin in view of Uppili and Maduskar does not specifically teach i) adding an alkaline reagent to remove chlorine or ii) adding the reagent to heated molten plastic downstream of the melting tank and upstream of the pyrolysis reactor.
With regard to i), Yoshida teaches a method for pyrolysis of plastic wastes (column 1, lines 8-10). Yoshida teaches adding a basic (alkaline) metal salt to the waste (column 8, lines 20 and 34-35), where the basic salt reacts with the halogen halides to form solid calcium salts (column 8, lines 49-51) which are removed from the pyrolysis reactor with the residues (pitch) (column 9, lines 9-10). Yoshida further teaches that the addition of the filler increases the decomposition rate and efficiency and improves the uniformity of the recovered oils (column 8, lines 10-25).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to add the basic metal salt of Yoshida to the plastics of De Bruin, because De Bruin and Yoshida each teach melting and pyrolysis of plastics, and Yoshida teaches that adding the basic metal salt to the plastics increases the decomposition rate and efficiency and improves the uniformity of the recovered oils (column 8, lines 10-25).
With regard to ii), De Bruin in view of Yoshida does not specifically teach adding the metal salt to a melted plastic downstream of melting and upstream of pyrolysis. However, this is merely a selection of an order of adding ingredients to form the same composition. Any change in the sequence of adding ingredients is prima facie obvious in the absence of new or unexpected results (see MPEP 2144.04(IV)C). The alkali reagent is present in the pyrolysis reactor in either scenario of adding it upstream of the melting or downstream of the melting. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to add the filler to the melted plastic, as claimed, because this is merely a change in the sequence of adding ingredients that would be expected to have the predictable result of producing the same melted plastic comprising an alkaline reagent as claimed, absent any evidence to the contrary.
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 ALYSSA L CEPLUCH whose telephone number is (571)270-5752. The examiner can normally be reached M-F, 8:30 am-5 pm, EST.
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/Alyssa L Cepluch/Examiner, Art Unit 1772
/IN SUK C BULLOCK/Supervisory Patent Examiner, Art Unit 1772