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, 2, and 5-7 are amended.
The Examiner appreciates the reformatting of the claims as suggested to include line breaks and indentations. The amendments to claims 1, 2, and 5-7 overcome most of the previous claim objections and 112(b) rejections, with the exceptions put on record again below.
Claims 1-7 are pending for examination below.
Response to Arguments
Applicant’s arguments, see Remarks, filed 13 July 2026, with respect to the 112(b) rejections over “wax-based”, “pyrolysis dry gas”, “light wax oil”, “heavy wax oil”, “upper part”, “positive conical shape”, “reverse conical shape”, and “carrying reactor” as in claims 1-3 and 7 have been fully considered and are persuasive. The Examiner has accepted the interpretations in the Remarks and places them on record below. Thus, the 112(b) rejections of claims 1-3 and 7 over those phrases have been withdrawn.
Applicant's arguments filed 13 July 2026 with respect to the 112(b) rejections over “self-heating” and “high temperature oil slurry” as well as with respect to the 103 rejections have been fully considered but they are not persuasive.
Applicant argues on page 5 of the Remarks that “self-heating” refers to a process where heat required for the melting dechlorination reactor is self-sufficient by means of closed-loop circulation of the slurry oil from the fractionating tower without external supply, which is distinguished from prior art circulating processes, and thus “self-heating” is not indefinite.
In response, the Examiner respectfully disagrees. While Applicant is allowed to be their own lexicographer, the term must be clearly defined in the instant application if the term is not a common term of art. The term “self-heating” does not appear to be a term of the art. The instant application does not provide a clear definition of “self-heating” beyond the description in the claim, and the description in the Remarks is not sufficient for this purpose. The Examiner further notes that the instant claim does in fact require external heating as part of the self-heating (see claimed second step as indented). Thus, it remains unclear what exactly is meant by “self-heating” and the claim remains indefinite.
Applicant argues on page 7 of the Remarks that the phrase “high-temperature oil slurry at a temperature of larger than or equal to 350°C” is describing the distillation boiling point range of a “slurry oil” and thus is not indefinite.
In response, the Examiner respectfully disagrees. While the Applicant’s explanation of the terms makes sense, if this explanation is supported by the instant specification, the claim needs to be amended to state this wording clearly, rather than the current wording. As worded, one of ordinary skill would not understand “at a temperature larger than or equal to 350°C” to mean the distillation range, as conventionally in the art when something is “at” a temperature, this means the current temperature of the liquid/gas, not the distillation range. Also, if “oil slurry” means “slurry oil”, this amendment should also be made, as one of ordinary skill in the art would understand the transposition of words can still be supported, and “slurry oil” is the conventional term in the art.
Applicant argues on page 9 of the Remarks that Whittington only discloses preheating the olefin polymer to 150-200°F (65.6 to 93.3°C) prior to pyrolysis in the pipe which comprises water which is cooled when heating the olefin feed, which is a different purpose than the claimed water cooling pipe which is to prevent thermal radiation from the dechlorination reactor from affecting the feed pipe.
In response, Whittington teaches that the feed pipe is at the temperature of about 150-200°F (65.6 to 93.3°C) (column 3, lines 4-4). This is within the claimed temperature range. The feed pipe of Whittington also comprises water being cooled during the preheating (column 3, lines 70-73). Thus, the feed pipe of Whittington is the same as the claimed feed pipe. A reference is not required to have the same motivation as the claimed invention to render obvious the claimed components, and the argued motivation is not claimed. Therefore, absent any evidence to the contrary, the feed pipe of Whittington continues to render obvious the claimed feed pipe.
Applicant also argues on page 9 of the Remarks that the references fails to teach or disclose the melting dechlorination and desulfurization pretreatment, and thus do not render obvious the subsequent processing steps including the melting recycle circulation heating.
In response, Applicant has not provided any specific missing teaching or issue with the rejection. The rejection previously and again in the Action below explains that Basha in view of Slivensky renders obvious the claimed melting preheating steps, and Basha in view of Whittington renders obvious the claimed melting dechlorination desulfurization steps. Absent any specific evidence to the contrary, these obviousness rejections are maintained.
Applicant argues on pages 9-10 of the Remarks that the claim requires a downer bed reactor, which does not have fluidizing gas, and Basha teaches a downflow fluidized bed reactor, which is argued as distinct.
In response, the claims do not have any language which distinguishes the claimed “downer” reactor from the “downflow” reactor of Basha. In the art, “downflow” and “downer” are often used as synonyms (see US 5,468,369 column 3, line 41 and US 2022/0081624 paragraph [0048] for example). Thus, absent specific claim language which distinguishes the claimed reactor from Basha and is supported by the instant application as filed, the downflow reactor of Basha continues to render obvious the claimed downer reactor.
Applicant argues on page 10 of the Remarks that while Duffy teaches a flue gas being discharged, none of the references teach adding the flue gas to the regenerator.
In response, the Examiner respectfully disagrees. As recited in the rejection, Duffy further teaches that the combustion in a regenerator can be supplemented by a fuel gas produced by the process (paragraph [0086]). Duffy also teaches a process for pyrolysis of polymers (Abstract) comprising heating before pyrolysis to obtain a gas stream comprising chlorine (paragraph [0081]). The gas stream is scrubbed (subjected to a dechlorination treatment). As acknowledged in the rejection, while Basha in view of Slivensky and Duffy does not explicitly teach the fuel gas in the regenerator is from the scrubbing step, because Basha and Duffy each teach a supplemental fuel in the regenerator, and Duffy teaches producing a gas which can be burned from the dechlorination and teaches adding fuel gas (which is understood as being burned) from the process to the regenerator, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the scrubbed (dechlorinated) gas as the fuel gas in the regenerator in the process of Basha in view of Duffy in order to save money on fuel costs and use renewable sources which are beneficial to the environment.
Applicant argues on pages 10-11 that the claimed self-heating system is an integrated system which achieves a total liquid product yield of 96% as demonstrated in Example 1, which is more than 25 percentage points higher than conventional waste plastic pyrolysis, and also achieves high yields of valuable products. Thus, the claimed process is not mere aggregation of known steps but instead is an integrated process which has demonstrated improvement over the prior art.
In response, the Examiner respectfully disagrees that the Example 1 provides evidence of unexpected results. While Example 1 recites yields of each part, there is no comparative example to determine if the yields are significantly increased. The recitation that the Example 1 process has a yield which is increased by 25 or more percentage points over the conventional waste plastic pyrolysis technology is mere assertation in paragraph [0046]. There is no support for this in explaining what is considered “convention” pyrolysis, as there are a wide variety of pyrolysis processes known in the art. As such, there is no evidence that the claimed process provides any critical or unexpected results, and the combination remains obvious.
The Examiner failed to include a 103 rejection of claim 3 in the previous Office Action. As such, the rejection below is made Non-Final.
Claim Interpretation
The following terms are being placed on the record with the definitions agreed upon by the Examiner and Applicant as in the Remarks of 13 July 2026.
-The term "wax-based chemicals" refer to the light wax oil and heavy wax oil described in paragraph [0046] of the specification.
-The term "pyrolysis dry gas" should be understood as a stream comprising non-condensable gases including H2, CO, CO2, methane, ethane, and ethylene.
-For the terms “top" and "the upper part", the present specification describes that the fuel gas is withdrawn from the top of the dechlorination reactor, while the high-temperature oil slurry is recycled from the upper part of the dechlorination reactor. As shown in FIG. 1, the upper part of the melting dechlorination reactor and the top of the melting dechlorination reactor are not the same position, where the upper part is situated below the top.
-The terms "light wax oil" and "heavy wax oil" are understood in the art of waste plastic conversion, wherein light wax oil is understood as having a distillation range of 150-250°C, and heavy wax oil is understood as having a distillation range of 250-350°C.
-The terms "positive conical shape" and "reverse conical shape" are defined as follows: "positive conical shape" refers to a cone shape that tapers toward the top, and "reverse conical shape" refers to a cone shape that tapers toward the bottom.
The term "carrying reactor" refers to a segment of the riser regenerator which has a dilute or transport flow regime.
Claim Objections
Claim 7 is objected to because of the following informalities:
With regard to claim 7, the claim recites in lines 4 and 5 “the equivalent diameter” and in line 7 “the diameter ratio”. These phrases lack antecedent basis and should be amended to “an equivalent diameter” and “a diameter ratio”, respectively.
Appropriate correction is required.
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 1-7 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.
With regard to claim 1, the claim has the following issues:
-In line 2, the claim recites “self-heating melt dechlorination”. It is unclear what is meant by “self-heating”, as this is not a term commonly used in the art and there is no definition in the instant specification. As explained above, the explanation in the Remarks is insufficient to define the term.
For purposes of examination, the claim later recites that heat for the melting comes from circulating and heating with external heating a molten liquid stream from the melting reactor (indented second step). Any process which comprises the same step of circulating and heating the molten liquid will be considered equivalent to the claimed “self-heating”. The Examiner suggests that if this interpretation is correct, the phrase “self-heating” does not add any patentable weight to the claim, and should be deleted.
-In the last indented step, the claim recites “high temperature oil slurry”. “The term “high temperature” is a relative term which renders the claim indefinite. The term “high temperature” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. It is also not clear whether the “high temperature” refers to the boiling point of the “oil slurry” or if it refers to the actual temperature. Further, it is unclear whether “oil slurry” is an oil slurried with something, or is a misstatement of the common fraction “slurry oil”.
For purposes of examination, there is no further information in the specification. Thus, the Examiner will give the broadest reasonable interpretation that the phrase is referring to the common fraction “slurry oil” and that the “high temperature” merely refers to the boiling point being higher than other fractions, because the claim later goes on to state a specific temperature. If this interpretation is correct, appropriate amendments to recite “slurry oil” and delete “high temperature” as unnecessary are respectfully requested.
-In the last indented step, the claim recites “the high temperature oil slurry at a temperature larger than or equal to 350°C is directly recycled…” It is unclear whether this temperature refers to the distillation range of the oil, or the temperature of the oil when it is recycled to the melting reactor, as something described as “at a temperature” is usually describing the temperature of the thing at the moment it is being described, rather than temperature properties such as distillation range. Thus, the claim is indefinite.
For purposes of examination, the temperature of the melting reactor is maintained at 240-320°C, which is lower than the temperature of “larger than or equal to 350°C” recited in this last indented step. Thus, the Examiner will interpret that the range refers to the boiling point of the fraction. Appropriate amendment to recite that this is the boiling point range or distillation range, if this is supported in the specification, is respectfully requested.
With regard to claims 2-7, the claims are rejected as being dependent on a rejected base claim.
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 1-4 are rejected under 35 U.S.C. 103 as being unpatentable over Basha et al. (US 2023/0183582) in view of Whittington (US 3,087,922), Slivensky et al. (US 2026/0042717), Duffy (US 2025/0101312), Wu et al. (US 2025/0128249), Miller et al. (US 6,150,577), and Colorado School of Mines (Refinery Feedstocks & Products Properties & Specifications).
With regard to claim 1, Basha teaches a method for catalytic pyrolysis of plastics (Abstract) comprising the following steps:
a) providing a mixed waste plastics comprising polyethylene (PE) and polypropylene (PP) (paragraph [0063], second column) through a controllable feeder (paragraph [0013], Figure).
b) melting the mixed waste plastics to form a molten liquid (paragraph [0034]).
c) atomizing the molten plastics (paragraph [0065]) and sending them to a catalytic downflow pyrolysis reactor (paragraph [0068]).
d) pyrolyzing the atomized molten plastics in the downflow reactor, wherein the catalyst enters the top of the downflow reactor and passes to the bottom and includes a regenerated catalyst (paragraph [0068]). Basha further teaches the temperature of the catalytic pyrolysis is 450-750°C (paragraph [0073]), the pressure is 0.5 to 10 bar (50 to 1000 kPa), and the residence time is 0.5 to 180 seconds (paragraph [0069]). These ranges overlap the temperature of 410-550°C, the pressure of 80-100 kPa, and the time of 200 ms to 2 sec of instant claim 1, rendering the ranges prima facie obvious. Basha does not explicitly teach that the pyrolysis comprises mixing, vaporization, and cracking, as claimed. However, Basha teaches the same atomized feed at similar temperatures, pressures, and residence times in the presence of a similar regenerated catalyst, and one of ordinary skill in the art is well aware that pyrolysis comprises cracking the plastics. Therefore, one of ordinary skill in the art would reasonably conclude that the pyrolysis of Basha also comprises the claimed mixing, vaporization, and cracking, absent any evidence to the contrary.
e) separating the catalyst from the product at the bottom of the reactor (paragraph [0068]) where the separation separates solid catalyst from gas products (gas-liquid separator) (paragraph [0036]).
f) passing the separated catalyst to the bottom of an upflow (riser) regenerator (paragraph [0083]).
g) regenerating the catalyst by combustion in the presence of air (paragraph [0039]) and a fuel gas (paragraph [0038]) at a temperature of 650-750°C (paragraph [0080]) which is within the range of 500-750°C of instant claim 1.
h) separating the catalyst from the regenerator in a cyclone (gas solid separator) and recycling the regenerated catalyst (coarse particle catalyst) back to the downer reactor for pyrolysis (paragraph [0041]).
i) recovering heat from the flue gas of the regenerator by other means (paragraph [0038]) and passing the flue gas as a vent stream (discharged outwardly) (paragraph [0040]).
j) fractionating the pyrolysis gas product to obtain a byproduct stream comprising methane, ethane, propane, butane, H2, CO2, and CO (pyrolysis dry gas) (paragraph [0038]), an olefin fraction (paragraph [0085]), and an aromatic fraction (paragraph [0084]). Basha teaches the catalytic pyrolysis takes place at a temperature of 450-750°C (paragraph [0073]) and while quenching of the effluent is an option, it is not required (paragraph [0084]). When the quenching does not take place, the products are expected to be at the same temperature as the reactor, absent any evidence to the contrary. This range of 450-750°C overlaps the range of 410-500°C of instant claim 1, rendering the range prima facie obvious.
k) recycling the byproduct stream (pyrolysis dry gas) to the feeder to feed the plastics (paragraph [0038]).
Basha fails to teach (i) a water cooling feed pipe at a temperature of 20-95°C for the feeder; (ii) melting and dechlorinating the plastics in an oil slurry molten liquid at a temperature of 240-320°C by stirring and mixing, passing a part of the molten liquid through a circulating tube with external heating and recycling the heated liquid to an upper part of the melting and dechlorinating reactor; (iii) dechlorinating a gas obtained from the melting and using it as the fuel gas to the regenerator; (iv) the flow rate of the circulation tube; (v) the mass ratio of circulating molten plastic to molten plastic in the melting reactor; (vi) steam in the atomizing and the amount of steam; (vii) the temperature of the regenerated catalyst; (viii) separating a fine catalyst from the regenerator gas and recycling the fine catalyst to the regenerator; (ix) that the flue gas heat is recovered in a boiler; (x) separating of the pyrolysis product into an alpha-olefin stream, a light wax product, a heavy wax product, and a heavy oil having a boiling point of at least 350°C; (xi) the amount of byproduct (pyrolysis dry gas) recycled to the feeder as carrier gas; or (xii) recycling the high temperature slurry oil to the melting and dechlorination reactor as the oil slurry heat source for the melting and dechlorination.
With regard to water cooling (i), Whittington teaches a method for pyrolysis of olefin polymers (column 1, lines 10-12). Whittington teaches that the process comprises a feeder, a feed pipe, and a pyrolysis reactor (Figure) where the process comprises quenching the product by heating a coolant, and then heating the feed in the feed pipe with the heated coolant (column 1, lines 59-62 and Figure) where the coolant can be water (column 3, lines 70-73). Whittington additionally teaches the temperature of the pipe is 150-200°F (65.6 to 93.3°C) (column 3, lines 4-5), which is within the range of 20-95°C of instant claim 1. Whittington further teaches that the quench and preheat provide means for allowing the olefin polymers to be converted (column 1, lines 46-50) and that water specifically allows the cooling and heating to take place rapidly (column 3, lines 58-62).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to add the step of passing the plastics through a water-cooling feed pipe at the claimed temperature because Basha and Whittington each teach passing polyolefin plastics from a feeder to a reactor, and Whittington teaches that adding the water-cooling steps provide means for allowing the olefin polymers to be converted (column 1, lines 46-50) and that water specifically allows the cooling and heating to take place rapidly (column 3, lines 58-62).
With regard to the melting steps (ii), Basha teaches melting the plastics before feeding them to the reactor, but is silent regarding the specific steps of the melting.
Slivensky teaches a method for catalytic pyrolysis of polyolefin plastics (paragraphs [0097] and [0100]). Slivensky teaches that the method comprises the following steps (Fig. 4 and corresponding paragraphs):
a) passing the plastics to a continuously stirred melt tank comprising a solvent (paragraph [0065] and Fig. 4) where the solvent is a heavy refinery stream or pyrolysis oil stream (paragraph [0054]) and is maintained at a temperature of 240-425°C (paragraph [0072]). This overlaps the temperature of 240-320°C of instant claim 1, rendering the range prima facie obvious. Slivensky teaches that the melting also performs dehalogenation by producing a halogen-enriched gas (fuel gas) (paragraph [0088]).
b) extracting at least a portion of the molten liquid from the melt tank (paragraph [0066], Fig. 6) and further heating the liquid in an external heat exchanger (paragraph [0067]). Slivensky does not explicitly teach that the heating is to a temperature 20-60°C higher than the molten liquid. However, Slivensky teaches further heating, and that the further heating is used to maintain the heating of the plastic (paragraph [0080]). Thus, the amount of additional heating is a result-effective variable, and can be optimized. Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to perform the further heating to a temperature 20-60°C higher than the melting tank, as claimed, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05(II).
c) passing the heated stream back to the top of the melting reactor in a circulating system (paragraph [0067]).
Slivensky teaches that the melting process allows the viscosity of the plastics to be reduced (paragraph [0051]) and that the further heating is used to maintain the temperature for melting the plastic (paragraph [0080]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the melting steps of Slivensky in the process of Basha, because Basha teaches melting but is silent regarding the specifics, and Slivensky teaches that the claimed melting steps provide a reduced viscosity feed and maintain the temperature for melting the plastics (paragraphs [0051]-[0080]).
With regard to dechlorinating a gas and using as fuel in regenerator (iii), Duffy teaches a process for pyrolysis of polymers (Abstract) comprising heating before pyrolysis to obtain a gas stream comprising chlorine (paragraph [0081]). The gas stream is scrubbed (subjected to a dechlorination treatment) and routed to a burner (paragraph [0081]). Duffy further teaches that the combustion in a regenerator can be supplemented by a fuel gas produced by the process (paragraph [0086]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to add the scrubbing step to the process of Basha in view of Slivensky, because Slivensky and Duffy each teach dechlorination to produce a halogenated gas stream, and Duffy teaches that scrubbing the gas stream allows it to be burned (paragraph [0081]).
While Basha in view of Slivensky and Duffy does not explicitly teach the fuel gas in the regenerator is from the scrubbing step, because Basha and Duffy each teach a supplemental fuel in the regenerator, and Duffy teaches producing a gas which can be burned from the dechlorination and teaches adding fuel gas (which is understood as being burned) from the process to the regenerator, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the scrubbed gas as the fuel gas in the process of Basha in view of Duffy in order to save money on fuel costs and use renewable sources which are beneficial to the environment.
With regard to the flow rate of the circulation heat exchanger (iv), the flow rate of the molten plastics through the heat exchanger affects the amount of heating received by the plastics, and thus affects the temperature of the melting reactor. As such, the flow rate through the heat exchanger is a result-effective variable, and can be optimized.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use a flow rate of 2-30 m/s such that the circulating tube is a high-speed circulating tube, as claimed, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05(II).
With regard to the mass ratio of circulating plastic to molten plastic (v), the ratio of recirculated plastic (circulating plastic) to removed plastic sent to the pyrolysis reactor (raw material) is 1:1 to 10:1 (paragraph [0079]), which is identical to the range of (1-10):1 of instant claim 1.
With regard to the steam (vi), Basha teaches gas for fluidizing the reactor, but does not specifically teach steam (paragraph [0068]).
Slivensky teaches a method for catalytic pyrolysis of polyolefin plastics (paragraphs [0097] and [0100]). Slivensky teaches that the method comprises steam as a feed or fluidization gas in an amount of 0 to 5 wt% (paragraph [0101]). This overlaps the amount of 4 to 12 wt%, rendering the range prima facie obvious.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use steam as the fluidization gas of Basha teaches Basha teaches a gas but is silent regarding steam, and Slivensky teaches that steam is a suitable fluidization gas for similar plastics in a similar catalytic pyrolysis reaction (paragraph [0101]).
With regard to the temperature of the regenerated catalyst (vii), Basha teaches that the temperature of the regenerator is 650-750°C (paragraph [0080]), and one of ordinary skill in the art knows that combustion is an exothermic reaction. Basha is silent regarding cooling the catalyst after regeneration. Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention that the temperature of the catalyst after regeneration is at least the temperature in the regenerator, or greater than 650°C. This overlaps the range of 600-800°C of instant claim 1, rendering the range prima facie obvious.
With regard to the separation of catalyst fines (viii), Basha teaches the process above, where the flue gas comprising catalyst from the upflow regenerator is sent to one or more cyclones to separate the catalyst (paragraph [0033]).
Basha does not specifically teach that one of the cyclones separates catalyst fines and returns them to the regenerator for further regeneration.
Wu teaches a process for catalytic pyrolysis of plastics (Abstract) comprising passing the catalyst to a regenerator, separating regenerated catalyst from the flue gas, sending a portion to the pyrolysis reactor and recycling a portion to the oxidative dehydrogenation (paragraph [0132] and Figure 1). Wu further teaches that the flue gas comprises catalyst fines as well, which can be removed from the flue gas so that the gas can be used to heat the reactor (paragraph [0136]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to remove the catalyst fines in a second separator and recycle the fines to the regenerator, because Basha and Wu each teach catalytic pyrolysis, regeneration of the catalyst to produce a flue gas stream comprising catalyst, and separation and recycle of the regenerated catalyst, and Wu teaches that the flue gas also comprises fines which should be removed, and teaches recycling at least a portion of the catalyst to the regenerator (paragraphs [0132] and [0136]).
With regard to the waste heat boiler (ix), Schumann teaches a process of pyrolyzing plastics (column 6, lines 19-21) wherein the process further comprises recovering heat from a flue gas in a waste heat boiler and heat is used to generate steam for the process (column 6, lines 55-59).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to recover heat in the waste boiler, because Basha and Schumann each teach recovering heat from a flue gas during plastic pyrolysis, Basha is silent regarding all the options for recovering heat, and Schumann teaches that a waste heat boiler is used to recover heat and use the heat to generate steam which is used in the process (column 6, lines 55-59).
With regard to the alpha olefin, light wax, and heavy wax fractions (x), Miller teaches a process for conversion of waste plastics comprising polyolefins by pyrolysis to produce a pyrolysis effluent (Abstract) and separating the effluent into 2 or more streams including a light gasoline or naphtha range fraction comprising 1-olefins (alpha olefins) (column 4, lines 20-24), a 650°F+ wax fraction (light wax), and a 1000°F+ wax fraction (heavy wax) (column 19, Table XIV and column 16, lines 6-7). Miller teaches that the pyrolysis temperature is 500-700°C (column 3, lines 30-31), which overlaps the range of 450-750°C of Basha. Miller additionally teaches that the process provides a highly desirable high yield of high VI lubricating oil compositions (column 2, lines 27-30).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to operate the process of Basha to provide the products as in the process of Miller, because Basha and Miller each teach pyrolysis of plastics to produce olefin containing products, Miller teaches that the operating conditions can be adjusted to produce the desired waxes (column 3, lines 39-46), and Miller further teaches that the products are useful as lubricating oils having high VI (column 2, lines 27-30).
With regard to the heavy oil fraction having a boiling point greater than 350°C (x), Slivensky teaches a method for catalytic pyrolysis of polyolefin plastics (paragraphs [0097] and [0100]). Slivensky teaches that the method comprises separating the product in a distillation column to produce multiple fractions including an atmospheric residue fraction (paragraph [0111]) which Colorado School of Mines evidences has a boiling point of 340°C+ (page 21, Table). This overlaps the range of 350°C+ of instant claim 1, rendering the range prima facie obvious.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to separate a heavy oil having a boiling point of 350°C+ from the product of Basha, because each of Basha and Slivensky teach catalytic pyrolysis to produce products which are distilled, Basha does not explicitly teach a heavy fraction, and Slivensky teaches that a heavy fraction having a boiling point of 350°C+ is produced from the catalytic pyrolysis and can be separated.
With regard to the amount of byproduct (pyrolysis dry gas) recycled to the feeder as carrier gas (xi), the amount of gas used in the feeder as carrier gas affects the amount of the plastics passed through the process. As such, the amount of pyrolysis dry gas used as the carrier gas is a result-effective variable, and can be optimized.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use 3-20 vol% of the pyrolysis dry gas as the carrier gas, as claimed, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05(II).
With regard to recycling the heavy oil having a boiling point of 350°C+ to the melting step (xii), Slivensky teaches a method for catalytic pyrolysis of polyolefin plastics (paragraphs [0097] and [0100]). Slivensky teaches that the method comprises separating the product in a distillation column to produce multiple fractions including an atmospheric residue fraction (paragraph [0111]) which Colorado School of Mines evidences has a boiling point of 340°C+ (page 21, Table). This overlaps the range of 350°C+ of instant claim 1, rendering the range prima facie obvious. Slivensky further teaches that the solvent in the melting step is a recycled pyrolysis oil fraction (paragraph [0052]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the heavy oil having a boiling point of 350°C+ as the solvent in the melting step, because Slivensky teaches separation of the heavy oil from the pyrolysis oil and also teaches a portion of the pyrolysis oil as the solvent in the melting step, and one of ordinary skill in the art would find it obvious to select any portion of pyrolysis oil, as this is a selection from a finite list of options with a reasonable expectation of success and without undue experimentation.
With regard to claim 2, the water-cooling feed pipe of Whittington has a reverse conical shape (Fig. 1, connection between the feed hopper and exchanger).
With regard to claim 3, Whittington teaches that the water-cooling feed pipe has a reverse conical shape (Figure 1 as above), which is not the positive conical shape as claimed. However, changes in shape are prima facie obvious absent evidence of criticality or unexpected results of the shape. See MPEP 2144.04IVB. The instant specification does not provide any evidence of benefits of the positive conical shape over the reverse conical shape of Whittington. Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the positive conical shape for the cooling pipe, as claimed.
With regard to claim 4, Basha teaches the controllable feeder includes a screw auger (single-axis screw feeder) (paragraph [0033]).
Claims 5 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Basha et al. (US 2023/0183582) in view of Whittington (US 3,087,922), Slivensky et al. (US 2026/0042717), Duffy (US 2025/0101312), Wu et al. (US 2025/0128249), Miller et al. (US 6,150,577), and Colorado School of Mines (Refinery Feedstocks & Products Properties & Specifications) as applied to claim 1 above, and further in view of Brian (US 2022/0034505).
With regard to claims 5 and 6, Basha in view of Slivensky teaches heating the circulating molten liquid in a heat exchanger (Slivensky paragraph [0066], Fig. 4).
Basha in view of Slivensky does not teach that the heating of the circulating molten liquid can be done with electromagnetic induction heating.
Brian teaches a process for pyrolysis (paragraph [0012]) where heating of the feedstock can be performed with heat exchange or induction coils (paragraph [0013]). Brian teaches that the use of induction heating instead of heat exchange allows for more efficient transfer of heat to the feedstock relative to heat from heat exchange (paragraph [0073]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use electromagnetic induction heating instead of heat exchange in the process of Basha in view of Slivensky, because Basha in view of Slivensky and Brian each teach heating the pyrolysis feed, and Brian teaches that using induction heating instead of a heat exchanger allows for more efficient transfer of heat to the feedstock relative to heat from heat exchange (paragraph [0073]).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Basha et al. (US 2023/0183582) in view of Whittington (US 3,087,922), Slivensky et al. (US 2026/0042717), Duffy (US 2025/0101312), Wu et al. (US 2025/0128249), Miller et al. (US 6,150,577), and Colorado School of Mines (Refinery Feedstocks & Products Properties & Specifications) as applied to claim 1 above, and further in view of Owen et al. (US 5,128,108).
With regard to claim 7, Basha teaches the method above, where the regenerator is an upflow (riser) regenerator (paragraph [0083]).
Basha does not specifically teach the regenerator comprises a turbulent fluidized bed bottom part and a straight tube dilute phase upper part.
Owen teaches an apparatus for turbulent bed catalyst regeneration (Abstract). Owen teaches that the regeneration apparatus comprises a turbulent bed on the bottom and then a straight tube dilute phrase transport section (Abstract, Figure) where the straight tube dilute phase portion has a decreased diameter compared to the turbulent bed portion (column 5, lines 60-62 and Figure 2). Owen further teaches that such a regenerator allows for additional coke combustion and reducing the load on the cyclones (column 6, lines 48-50 and 61-63).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the regenerator of Owen in the process of Basha, because each of Basha and Owen teach catalyst regeneration in a riser regenerator, and Owen teaches the regenerator having the turbulent bed and dilute phase allows for additional coke combustion and reducing the load on the cyclones (column 6, lines 48-50 and 61-63).
Owen fails to teach the specific diameter of each section such that a ratio of the diameter of the turbulent bed to the straight tube is (2-3):1. However, Owen teaches that the cross-sectional area is adjusted to maintain the bed in fast fluidized condition (column 5, lines 47-50). Thus, the cross-sectional area and, it is also understood, the diameter factor of the cross-sectional area, is a result-effective variable, and can be optimized. Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to adjust the diameter of each section such that the ratio between the turbulent bed section and the dilute phase section is (2-3):1, as claimed, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05(II).
Conclusion
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/Alyssa L Cepluch/Examiner, Art Unit 1772
/Renee Robinson/Primary Examiner, Art Unit 1772
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