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, 3, and 8 are amended. Claims 10 and 11 are new.
The amendments to claims 1, 3, and 8 overcome the previous claim objections and 112(b) rejections.
Claims 1-11 are pending for examination below.
Response to Arguments
Applicant's arguments filed 05 November 2025 have been fully considered. As Applicant argues on page 9 and 15 of the Remarks, Streiff and Humphreys fail to characterize the wax in terms of carbon number or molecular weight and there is no motivation in Streiff or Humphreys to select the ranges, nor a demonstration that the wax of Streiff inherently has the claimed properties. Therefore, the rejection over Streiff and Humphreys is withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Streiff and Humphreys along with newly cited prior art Schaub as a secondary reference. The following rejection has been made Non-Final.
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, 7, 8, 10 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Streiff et al. (US 2019/0002664) in view of Schaub et al. (US 3,787,166) and Humphreys et al. (US 2020/0071619).
With regard to claims 1 and 10, Streiff teaches a method for producing waxes and liquid fuels from waste plastic (paragraph [0002]) comprising the following (see Fig. 2):
a) combining a diluent (transporting agent) and plastic waste (paragraph [0031]) and heating to liquefy the plastics (produce a molten mixture) (paragraph [0029]).
b) filtering the liquefied and diluted plastic to obtain a filtered and melted (molten) plastic (paragraph [0033]).
c) thermal cracking of the melted (molten) plastic to produce a product (paragraph [0034]) at a temperature of 425°C (paragraph [0065]) and a pressure of 100 to 500 kPa (1 to 5 bar) (paragraph [0036]). These are within the ranges of 350-650°C and 0.15 to 5 bar of instant claim 10.
d) separating from the product a liquid vapor mixture 15 (overhead stream) and a stream 16 comprising unconverted materials and coke (bottom stream) (Figure 2 and paragraph [0060]).
e) separating fuels from the liquid vapor mixture 15 (paragraph [0047]).
Streiff does not specifically teach i) that the diluent (transporting agent) is a wax having the claimed molecular weight and carbon number or ii) separation of the liquid vapor mixture (overhead stream) by flash separation to obtain the fuels and transporting agent wax.
With regard to i), Schaub teaches a process for thermal treatment of plastics (Abstract). Schaub teaches that the process comprises heating the plastics in a liquid at reaction conditions auxiliary mixture (diluent or transporting agent) (column 2, lines 20-22) where the auxiliary mixture can be polyethylene wax having a molecular weight of 1000-10000 g/mol (column 2, lines 37-42). This overlaps the range of 500 to 2000 g/mol of instant claim 1, rendering the range prima facie obvious. A polyethylene wax having a molecular weight of 1000-10000 has a carbon number of approximately 61-713, as follows:
The formula for polyethylene is (C2H4)n. The molecular weight of ethylene (C2H4) is 28.05 g. Thus, using the 1000 and 10000 g endpoints of the polymer weight, the formulas to obtain the range of n are
1000
28.05
=
35.65
and
10000
28.05
.
=
356.51
. For every unit of ethylene n, there are 2 carbon atoms, so the number of carbon atoms is approximately 61 to 713, rounding to the nearest integer. The range of 61-713 overlaps the range of 30-100 of instant claim 1, rendering the range prima facie obvious.
Schaub further teaches the presence of the auxiliary phase which is polyethylene wax facilitates the thermal decomposition and increases heat transfer (column 2, lines 23-26).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to add the polyethylene wax of Schaub to the process of Streiff, because each of Streiff and Schaub teaches thermal decomposition of plastics in the presence of a hydrocarbon which is used for heating the plastics, and Schaub teaches that polyethylene waxes having a molecular weight of 1000-10000 and thus a carbon number of approximately 61-713 provides the benefits of facilitating thermal decomposition and increasing heat transfer.
With regard to ii), Humphreys teaches a process comprising producing fuels from polymeric materials (Abstract). Humphreys teaches that the product is separated by means of flash separation to get a distillate (fuel) stream and a wax stream (transporting agent stream) (paragraph [0267] and Fig. 5). Humphreys further teaches that the flash separation allows for recovering heat from the product which can be used elsewhere in the process (paragraph [0268]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the flash separation of Humphreys in the process of Streiff and Schaub, because each of Humphreys and Streiff teaches conversion of plastic materials to fuels, Schaub teaches the use of polyethylene wax as the transporting agent, and Humphreys teaches that flash separation allows for recovery of heat along with separation of wax (transporting agent) and fuels, as claimed (paragraph [0268]).
With regard to claim 2, Schaub teaches that the amount of polyethylene wax (transporting agent) to plastic added is 1500 g to 2100 g (ratio of 0.7) 1500 g to 2550 g (0.59), 1500 g to 1715 g (0.87), or 1500 g to 1230 g (1.2) (columns 3-4, Examples 1-3 and 5). These are all within the range of a ratio of transporting agent to plastic of 0.3 to 3 of instant claim 2.
With regard to claim 3, Humphreys further teaches that after flash separation, the distillate (fuel) stream can be separated in a column to produce a light ends stream (gaseous fraction), a naphtha stream, a kerosene stream, and a diesel stream (paragraph [0270]). One of ordinary skill in the art is aware that naphtha and gasoline have overlapping boiling ranges, and so the naphtha stream recovered by Humphreys includes the gasoline stream as claimed.
With regard to claim 4, Streiff teaches the diluent is added to the plastic for liquefaction (paragraph [0031]). Streiff does not explicitly teach adding the diluent (transporting agent) to the reactor to contact the plastic to obtain the first mixture. However, it is understood that the liquefaction takes place in a reactor. Thus, adding the diluent to the plastic as taught by Streiff is understood to mean adding the diluent (transporting agent) to the reactor, as claimed.
With regard to claims 7 and 8, Schaub teaches the auxiliary liquid (transporting agent) is a polyethylene wax (column 2, lines 39-40). Schaub does not specifically teach the properties of the polyethylene wax. The instant specification recites that typical data for commercially available PE wax that can be used as the transporting agent includes a melting point of 90-100°C, a drop melting point of 95-105°C, a needle penetration of 3 to 8 mm, and a viscosity of up to 1000 cPs (page 11, Table 1). These ranges are within the claimed ranges of 90-115°C, 95-120°C and 2-8 mm, respectively, and overlaps the range of 10 to 100 cPs.
Therefore, because Schaub teaches a polyethylene wax having overlapping molecular weight and carbon number to the claimed transporting agent wax, and the instant specification recites the properties of the PE wax having the claimed molecular weight and carbon number are within the claimed property ranges, one of ordinary skill in the art would reasonably conclude that the properties of the PE wax of Schaub also overlap the ranges of the melting point, drop melting point, needle penetration, and viscosity for PE wax, thus rendering the claimed ranges prima facie obvious.
With regard to claim 11, Streiff in view of Humphreys teaches the flash separation of claim 1 above. Humphreys further teaches adjusting the pressure of the flash separation from 0.2 to 20 bar to obtain the desired product (paragraph [0268]). This overlaps the range of 0.15 to 5 bar of instant claim 11, rendering the range prima facie obvious.
Humphrey does not specifically teach the temperature of the flash vessel. However, one of ordinary skill in the art is aware that the temperature also affects the boiling point of the separation in a flash vessel, and that the temperature and pressure work together to allow the desired products to be separated. Thus, the temperature of the flash vessel is a result-effective variable, and result-effective variables are known to be able to be optimized.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to optimize the temperature to be 350°C to 650°C and a pressure of 0 to 5 bar to separate the waxes from the fuels in the flash vessel, 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).
Claims 5 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Streiff et al. (US 2019/0002664) in view of Humphreys et al. (US 2020/0071619) as applied to claim 1 above, and further in view of Hemmings (US 2022/0064539).
With regard to claim 5, Streiff in view of Humphreys teaches the method above, where the plastic and wax are liquefied (paragraph [0029]).
Streiff is silent regarding the temperature and pressure of the liquefaction.
Hemmings teaches a method for cracking of plastic waste to produce products (paragraph [0001]) where the process comprises a melting step of mixing plastic waste and waxes (paragraph [0043]) and melting at a temperature from 180 to 250°C and at atmospheric pressure (about 1 bar) (paragraph [0055]). This overlaps the range of 250-400°C, rendering the range prima facie obvious, and is within the range of 0 to 5 bar gauge of instant claim 5. Hemmings further teaches that the wax and plastic at this temperature help maintain the molten plastic in a pumpable state (paragraph [0068]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the temperature and pressure of Hemmings in the process of Streiff, because Streiff and Hemmings each teach cracking of a mixture of melted plastics and waxes to produce desirable products, Streiff is silent as to the melting conditions, and Hemmings teaches that the temperature and pressure above keep the melted mixture in a pumpable state (paragraph [0068]).
With regard to claim 6, Streiff in view of Humphreys and Hemmings teaches the process above, including the melting conditions. Hemmings further teaches that the recycled wax is hot, so as to provide a portion of the heat to the melting step (paragraph [0069]) and that the cracking takes place at a temperature of 325-450°C (paragraph [0074]). Thus, one of ordinary skill in the art would reasonably conclude that the recycled wax (transporting agent) is at a temperature hotter than the melting zone, in order to provide heat to the melting zone, and no hotter than the cracking temperature, as cracking is endothermic and the wax results from the cracking. Thus, the temperature of the recycled wax (transporting agent) is expected to be 180 to 450°C, which overlaps the range of 300 to 400°C of instant claim 6, rendering the range prima facie obvious.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Streiff et al. (US 2019/0002664) in view of Humphreys et al. (US 2020/0071619) as applied to claim 1 above, and further in view of Dixit (WO 2020/230157).
With regard to claim 9, Streiff teaches that the plastic waste is a mixed waste including PVC (halogen containing waste) (paragraph [0016]).
Streiff does not specifically teach dehalogenation the mixture before effective filtration or the temperature of the liquefying step.
Dixit teaches a method for melting plastics for plastic pyrolysis (Abstract). Dixit teaches that the plastic waste is a mixture of plastics including PVC (page 1, lines 19-20) and further teaches melting the waste in combination with waxes recycled from the process to produce a melted plastic for pyrolysis (page 1, lines 7-14). Dixit additionally teaches that the melting (liquefying) provides in situ reduction of chlorine from PVC (page 1, lines 24-29) where the melting evolves gases including chlorinated gases which are removed from the process (dehalogenation) (page 11, lines 22-25). The melting takes place at 150 to 300°C (page 1, lines 7-9), which overlaps the range of 200 to 300°C, rendering the range prima facie obvious. Dixit further teaches that the dehalogenation protects the downstream pyrolysis equipment and other process equipment from chlorinated contaminants (page 11, lines 25-29).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the temperature of Dixit in the melting of Streiff in order to remove halogenated gases from the plastic before pyrolysis, because each of Streiff and Dixit teaches melting plastics with waxes followed by pyrolysis, Streiff is silent regarding the melting temperature or dehalogenation, and Dixit teaches that the melting at the claimed temperatures removes chlorinated containments, protecting the pyrolysis equipment (page 11, lines 25-29).
Conclusion
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.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, In Suk Bullock can be reached at 571-272-5954. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/Alyssa L Cepluch/Examiner, Art Unit 1772
/IN SUK C BULLOCK/Supervisory Patent Examiner, Art Unit 1772