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The rejection described in the Office action mailed on 5/13/2026 has been withdrawn in view of the response filed on 8/12/2026. Because of the withdrawal of the rejection, the arguments concerning this rejection is considered to be moot and will not be addressed. A new Final Office Action follows.
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 16-19, 22-24, 28, and 29 are rejected under 35 U.S.C. § 103 as being unpatentable over Zhang et al. (WO 2020/178597 A1; “Zhang”) in view of Nesté et al. (WO 2021/105326 A1; “Nesté”) and Kurata (JPH0816226B; “Kurata”).
Regarding claim 16, Zhang teaches a process for upgrading pyrolysis oil derived from plastic or rubber waste and recognizes that such pyrolysis oil contains solid residues requiring removal (Zhang, ¶¶ 1, 8-10, 127-135). Zhang teaches treating the pyrolysis oil with an aqueous solution by mixing, stirring, or shaking the oil and aqueous solution, allowing an organic phase and an aqueous phase to form, and separating the phases (Zhang, ¶¶ 57-64, 86-98). Zhang further teaches that the aqueous solution may have a pH of about 5-10 and may contain an acid, including a C1-C4 carboxylic acid, or a base, including alkali-metal hydroxides and carbonates such as NaOH, KOH, Ca(OH)₂, Na₂CO₃, and K₂CO₃ (Zhang, ¶¶ 109–116). Thus, Zhang teaches adjusting/treating the pyrolysis oil by adding an aqueous solution having either an acidic or basic pH. Zhang additionally teaches filtration for removal of solid material from pyrolysis-oil-containing streams (Zhang, ¶¶ 104-108, 142-143), and teaches additional liquid-liquid processing in which the separated organic phase is treated with an upgrading solution to form extract and raffinate phases, which are thereafter separated (Zhang, ¶¶ 140-158). Zhang also teaches repeated aqueous washing in which a separated organic phase is contacted with a second fresh aqueous batch to form another organic/aqueous two-phase mixture followed by another separation (Zhang, ¶¶ 86-90).
However, Zhang does not expressly teach the claimed sequence wherein, after pH adjustment, a solid-liquid separation is necessarily performed and, after that solid-liquid separation, a further liquid-liquid separation is performed.
Nesté teaches treating liquefied waste plastics by contacting the material with an aqueous medium having a pH of at least 7 at a temperature of at least 200°C, followed by liquid-liquid separation (Nesté, p. 4, lines 25–35; p. 15, lines 1-5). Nesté teaches that the aqueous medium is preferably alkaline, preferably contains an alkali-metal hydroxide, and preferably has a pH of at least 8 or at least 9 (Nesté, p. 15, lines 24-35; p. 16, lines 1–4; claims 15-18). Nesté further teaches that additional pretreatment operations may be performed before and/or after the reactive extraction (Nesté, p. 16).
Kurata teaches waste-plastic oil treatment in which the oil is continuously stirred and washed with alkaline ionized water having a pH of 12.6 in washing/water-separation tanks 6a and 6b, thereby neutralizing/washing the waste-plastic oil. Kurata thereafter applies pressure to the treated oil using oil-feed pump Pb and passes the oil through forced filter 11 to remove impurities (Kurata, English translation, description of washing/water-separation tanks 6a and 6b, alkaline-ionized-water tank 18, oil-feed pump Pb, and forced filter 11).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to employ the filtration/solid-removal operation taught by Zhang and Kurata in conjunction with the aqueous treatment and liquid-liquid separation operations taught by Zhang and Nesté, and to perform a further liquid-liquid separation after the solid-liquid separation, because the references teach that filtration removes solid impurities whereas aqueous treatment followed by phase separation removes contaminants associated with the separate liquid phases. Employing these known separation operations sequentially would predictably provide further purification of waste-plastic pyrolysis oil for subsequent processing.
Regarding claim 17, Zhang teaches treating pyrolysis oil with aqueous solutions having a pH of about 5-10, including ranges of about 5-8 and about 6-8, and expressly teaches use of acidic aqueous solutions (Zhang, ¶¶ 109-111). These disclosed ranges encompass a pH of about 6.5 or less.
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to select a pH of about 6.5 or less within Zhang's disclosed acidic treatment range according to the contaminants to be removed and the desired treatment conditions.
Regarding claim 18, Zhang teaches use of basic aqueous treatment solutions comprising alkali-metal hydroxides or carbonates (Zhang, ¶¶ 112-116). Zhang, however, does not require a pH of about 8 or more.
Nesté teaches that the aqueous medium preferably has a pH of at least 8, and more preferably at least 9 (Nesté, p. 15, lines 24-35; p. 16, lines 1-4; claims 15-18). Kurata additionally teaches washing waste-plastic oil with alkaline ionized water having a pH of 12.6 (Kurata, English translation, description of washing/water-separation tanks 6a and 6b).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to employ an aqueous alkaline treatment solution having a pH of about 8 or more in Zhang's process because Nesté and Kurata teach such alkaline conditions for treatment of waste-plastic-derived oils.
Regarding claim 19, Zhang teaches performing solid-liquid separation by filtering pyrolysis-oil-containing material to remove solid material (Zhang, ¶¶ 104-108, 142-143).
Kurata likewise teaches passing treated waste-plastic oil under pressure through forced filter 11 to remove impurities (Kurata, English translation, description of washing/water-separation tank 6b, oil-feed pump Pb, and forced filter 11).
Accordingly, it would have been obvious to perform the solid-liquid separation of claim 16 by filtration.
Claim 22
Regarding claim 22, Zhang teaches filtration for removal of solids from the pyrolysis-oil-containing material (Zhang, ¶¶ 104-108, 142-143), but does not expressly require that the solid-liquid separation be performed using gravimetric forces, centrifugal forces, or a pressure difference.
Kurata teaches applying pressure to the treated waste-plastic oil by oil-feed pump Pb and thereafter passing the pressurized oil through forced filter 11 to remove impurities.
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to perform Zhang's solid-liquid filtration using a pressure difference as taught by Kurata in order to force the pyrolysis oil through the filter and facilitate removal of solid impurities.
Claim 23
Regarding claim 23, Zhang teaches liquid-liquid treatment comprising mixing pyrolysis oil with an aqueous treatment/extraction solution to form an organic phase and an aqueous phase and thereafter separating the phases (Zhang, ¶¶ 86-98). Zhang further teaches repeated mixing of the separated organic phase with fresh aqueous solution followed by phase separation (Zhang, ¶¶ 88–90).
Accordingly, Zhang teaches the liquid-liquid separation comprising extraction and/or mixing the pretreated crude pyrolysis oil with an extraction solution as recited in claim 23.
Regarding claim 24, Zhang teaches that mixing of the pyrolysis oil with the aqueous solution may be performed at ambient temperature, typically about 18-28°C, and more generally at temperatures of about 0-70°C (Zhang, ¶¶ 91-98). These disclosed temperature ranges overlap the claimed range of about 25°C or more and about 150°C or less.
Accordingly, the temperature limitation of claim 24 would have been obvious from Zhang's expressly disclosed overlapping treatment temperatures.
Regarding claim 28, Zhang teaches separating organic and aqueous phases during treatment of the pyrolysis oil (Zhang, ¶¶ 86–98, 140–158), but Zhang does not expressly teach recirculating or feeding back the residue, organic phase, or aqueous phase obtained from the further liquid-liquid separation to the pretreated crude pyrolysis oil.
Kurata teaches collecting aqueous alkaline treatment solution used in waste-plastic-oil purification, adjusting the pH of the recovered aqueous solution, storing the solution, and reusing the alkaline aqueous solution.
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to recirculate the spent aqueous solution obtained from the further liquid-liquid separation, optionally after pH adjustment or regeneration, for renewed contact with the pretreated crude pyrolysis oil, because Kurata teaches recovery and reuse of aqueous alkaline treatment solution. Such reuse would predictably reduce consumption of fresh aqueous treatment solution and reduce aqueous waste generation.
Regarding claim 29, Zhang teaches that plastic-derived pyrolysis oil contains solid residues and teaches filtration for removal of solids from pyrolysis-oil-containing material (Zhang, ¶¶ 8-10, 104-108, 142-143).
However, Zhang does not expressly teach performing at least one additional solid-liquid separation after the solid-liquid separation already applied to claim 16.
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to repeat the known solid-liquid separation when residual solids remain in the treated pyrolysis oil because repetition of the known filtration operation would predictably provide additional removal of residual solid contaminants and thereby improve the purity of the treated pyrolysis oil.
Claims 20 and 21 are rejected under 35 U.S.C. § 103 as being unpatentable over Zhang in view of Nesté and Kurata, as applied to claim 16 above, and further in view of Frey et al. (US 8,524,087 B2).
Regarding claim 20, Zhang in view of Nesté and Kurata teaches the process of claim 16, including solid-liquid separation by filtration, as discussed above. However, Zhang, Nesté, and Kurata do not teach an average filtration velocity of at least about 0.04 kg/(h·cm²).
Frey teaches filtration of pyrolysis oil and teaches that filter performance is characterized by “flux,” i.e., the volume of pyrolysis-oil feed filtered per unit filter area per unit time. Frey discloses an exemplary flux of approximately 0.007 L/hr/cm², teaches that higher filter flux is preferred, and teaches acceptable liquid filter fluxes ranging from about 0.001 to about 10 L/hr/cm² (Frey, col. 6, lines 9-19). Frey also teaches heating the pyrolysis oil and/or filter to increase the filtration rate (Frey, col. 6, lines 1-4).
Thus, filtration rate/flux was recognized in the art as a result-effective filtration variable. It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to optimize the filtration velocity of the process of Zhang/Nesté/Kurata according to throughput and solids-removal requirements, including selecting the claimed filtration velocity, through routine optimization of a known result-effective variable.
Regarding claim 21, Zhang in view of Nesté and Kurata teaches solid-liquid separation by filtration, as discussed above. However, Zhang, Nesté, and Kurata do not teach that the filter aid comprises diatomaceous earth, cellulose, perlite, or mixtures thereof.
Frey teaches that a filter aid may be employed to improve filtration of pyrolysis oil and specifically teaches suitable filter aids including Celite®, Norit®, and diatomaceous earth (Frey, col. 6, lines 4–9).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to employ diatomaceous earth as a filter aid in the filtration of the pyrolysis oil of Zhang/Nesté/Kurata in order to improve filtration performance, as taught by Frey.
Claim 25 is rejected under 35 U.S.C. § 103 as being unpatentable over Zhang in view of Nesté and Kurata, as applied to claim 16 above, and further in view of Borremans (WO 2008/145729 A1; “Borremans”).
Regarding claim 25, Zhang teaches contacting/mixing pyrolysis oil with an aqueous treatment solution using mixing, stirring, or shaking (Zhang, ¶¶ 86–98). Kurata similarly teaches stirring waste-plastic oil with alkaline ionized water in washing/water-separation tanks 6a and 6b (Kurata, English translation, description of tanks 6a/6b and stirring arms 19).
However, Zhang, Nesté, and Kurata do not teach that the stirring or conveying device has a power input per volume of 200 W/m³ or more and 16,500 W/m³ or less, or a Newton number of 2 or more.
Borremans teaches operating a liquid stirring system at an energy density/power input per liquid volume of at least 0.5 kW/m³, preferably at least 1 kW/m³ and more preferably at least 1.2 kW/m³, and generally at most 2 kW/m³, preferably at most 1.5 kW/m³ (Borremans, WO 2008/145729 A1, p. 13, lines 13–22). The disclosed range of 500–2,000 W/m³ falls within the claimed range of 200–16,500 W/m³.
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to operate the stirring device used for mixing the liquid phases of Zhang/Nesté/Kurata at a known effective stirring power, including the 500–2,000 W/m³ power density taught by Borremans, in order to provide effective mixing of the liquid medium. The resulting power input falls within the range recited in claim 25.
Claims 26 and 27 are rejected under 35 U.S.C. § 103 as being unpatentable over Zhang in view of Nesté and Kurata, as applied to claim 16 above, and further in view of Terrien et al. (US 6,315,131 B1).
Claim 26
Regarding claim 26, Zhang in view of Nesté and Kurata teaches the process of claim 16 including a further liquid-liquid separation, as discussed above. However, Zhang, Nesté, and Kurata do not expressly teach that the further liquid-liquid separation is performed using gravimetric forces or centrifugal forces.
Terrien teaches separation of mixtures of two immiscible fluids having different specific gravities, particularly oil and water, using gravity separation (Terrien, col. 1, lines 7-14; col. 2, lines 1-18). Terrien explains that gravity separation exploits the difference in specific gravity between oil and water, whereby the lighter oil rises and separates from the water (Terrien, col. 2, lines 1-18).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to perform the further liquid-liquid separation of Zhang/Nesté/Kurata using gravimetric forces as taught by Terrien because gravity separation provides a known means for separating immiscible organic and aqueous liquid phases based upon their difference in density.
Regarding claim 27, Zhang/Nesté/Kurata in further view of Terrien teaches the process of claim 26, including performing the further liquid-liquid separation using gravimetric forces. However, Zhang, Nesté, and Kurata do not teach that the further liquid-liquid separation uses one or more internal structural elements as recited in claim 27.
Terrien teaches that gravity oil/water separators conventionally employ internal coalescing structures, including tightly packed beds of coalescing media and closely spaced plates, wherein the plates may be grooved, channeled, wavy, or corrugated (Terrien, col. 2, lines 19-40). Terrien explains that these internal structures promote contact and coalescence of dispersed oil droplets and thereby improve liquid-liquid separation (Terrien, col. 2, lines 19-40).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to provide the gravity separator used in the further liquid-liquid separation with the internal coalescing structures taught by Terrien in order to promote droplet coalescence and thereby improve separation of the organic and aqueous phases.
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
