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 .
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1, 2, 3, 6, 7, 9, 10, 12, 13, 15, 16, 18, 19, and 21, in the reply filed on 6/12/2026 is acknowledged.
Claim Interpretation
Claim 1 is directed to a process for producing carbon nanofilaments; the term “nanofilament” is a broad term in the art which may be used interchangeably with terms such as “nanofiber” and “nanotube,” and alternatively indicates structures including but not limited to “nanofiber and “nanotube.” The broadest reasonable interpretation of the limitation of “carbon nanofilaments” will be applied wherein such equivalent terms are included in the interpretation.
Claim Objections
Claim 13 is objected to because of the following informalities: claim 13 recites “comprises” in reference to “the catalyst particles;” this is interpreted as a typographic error that should read “comprise.” Appropriate correction is requested.
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 1-3, 6-7, 9-10, 12, 19, 21, 140, and 143 are rejected under 35 U.S.C. 103 as being unpatentable over Denton et al. 2015 (US 20150059571 A1, herein referred to as Denton) in view of Abatzoglou et al. 2002 (US 20020116908 A1, herein referred to as Abatzoglou, on IDS of 2/13/2024).
Regarding claim 1, Denton teaches a process for producing carbon nanofilaments (“FIG. 12 is a process flow diagram of a method for generating CNTs from a feed gas that includes methane and carbon dioxide;” 0026; wherein carbon nanotubes are interpreted to fall within the scope of carbon nanofilaments) comprising:
feeding a reaction chamber containing carbon-sequestration catalyst particles (catalyst particles 712, 0105) with a continuous gaseous flow containing hydrocarbon compounds and carbon oxide (hot gas feed stream, 0105, 0100, Fig. 6) through a gas inlet (pipeline 706, 0105);
withdrawing gas from the reaction chamber through a gas outlet located above a bed of the catalyst particles contained in the reaction chamber (line 716, 0106);
Denton does not teach the following limitations:
inside the reaction chamber, introducing at least partially the continuous gaseous flow into a first gas conduit mounted above the gas inlet and vertically spaced-apart therefrom, the first gas conduit being opened at a first end and top end, opposed to the first end; and
whereby, during operation, the catalyst particles are siphoned up and fluidized by the continuous gaseous flow and travel up to the first gas conduit through a space defined between the first gas conduit and the gas inlet and through the first end of the first gas conduit, exits at the top end of the first gas conduit, and fall outside the first gas conduit to be recirculated.
However, Abatzoglou teaches an apparatus for the removal of particulate material from hot gas (abstract), which is relevant to the field of endeavor of the instant invention since it pertains to the filtration of solid particles from hot gas, and is relevant to the field of endeavor of Denton since Abatzoglou teaches a fluidized technical implementation (fluidized bed, 0010) analogous to the fluidization of Denton (Figure 7). Abatzoglou teaches inside the reaction chamber, introducing at least partially the continuous gaseous flow (0034) into a first gas conduit mounted above the gas inlet and vertically spaced-apart therefrom (tube 32, Figure 5), the first gas conduit being opened at a first end and top end, opposed to the first end; and Abatzoglou further teaches that during operation, particles (granular material, 0034) are siphoned up and fluidized by the continuous gaseous flow and travel up to the first gas conduit through a space defined between the first gas conduit and the gas inlet and through the first end of the first gas conduit, exits at the top end of the first gas conduit, and fall outside the first gas conduit to be recirculated (0034).
It would be obvious to combine the teachings of Denton and Abatzoglou, whereby the granular material of Abatzoglou are substituted by the catalyst particles of Denton; one would be motivated to do so because Denton teaches that the catalyst particles may be separated from the reactor stream in order to be recirculated (0049, 0107) and Abatzoglou teaches that combining such a separation step with the fluidized bed of the reactor combines the benefits of both without needing recirculating pumps (0010-0011). Abatzoglou teaches that the tubular structure allows for fluidization to occur inside the tube (0030) which advantageously continuously renews the material and homogenizes the bulk of the material (0036). Therefore one skilled in the art would arrive at the claimed invention prior to the effective filing date.
Regarding claim 2, Denton and Abatzoglou teach the process as applied to claim 1. Denton further teaches preventing the catalyst particles from flowing into the gas inlet (via distributor plate 710, 0105) and teaches a distributor plate (710, 0105) covering the inlet 706 (Fig. 7). Denton does not teach that the distributor plate is a partition grid. However, it is interpreted to meet this limitation, since the function of the partition grid as claimed is to prevent the particles from flowing into the gas inlet, and the function of the distributor plate of Denton is to prevent particles from flowing downward into the gas inlet (Fig. 7). Therefore it is interpreted that Denton teaches the claimed invention. Similarly, Abatzoglou teaches a distribution plate provided to prevent granular material from entering or blocking the inlet (claim 10). One skilled in the art therefore would have arrived at the claimed invention prior to the effective filing date.
Regarding claim 3, Denton and Abatzoglou teach the process as applied to claim 1. Denton further teaches that the hydrocarbon compound comprises carbon (methane, which comprises carbon, 0061, 0078) and the carbon oxide comprises carbon dioxide (carbon dioxide, 0078).
Denton does not explicitly teach the molar ratio of C/CO2 in the continuous gas flow fed to the reaction chamber being between about 0.5 and 2. However, Denton teaches that the molar ratio is a parameter that determines whether solid carbon will form (Fig. 2; 0054-0059); therefore Denton teaches the molar ratio as being a result effective variable of the invention. Accordingly, one of ordinary skill in the art before the effective filing date of the invention would have optimized, by routine experimentation, the molar ratio in the teaching of Denton to obtain the desired balance between carbon and carbon dioxide as taught by Denton (Figure 2) (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223). “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Therefore one skilled in the art would arrive at the claimed invention prior to the effective filing date.
Regarding claim 6, Denton and Abatzoglou teach the process as applied to claim 1. Abatzoglou further teaches providing the continuous gaseous flow to the reaction chamber through a tapered portion thereof (12, Fig. 5) having a funnel shape and the catalyst particles fall outside the first gas conduit and towards the tapered portion of the reaction chamber to be recirculated (0034). It would be obvious to combine the tapered funnel shape of the reactor bottom taught by Abatzoglou with the teachings of the prior art; one would be motivated to do so in order to direct the particles towards recirculation, as Abatzoglou teaches (0012). One skilled in the art would therefore arrive at the claimed invention prior to the effective filing date.
Regarding claim 7, Denton and Abatzoglou teach the process as applied to claim 1. Denton further teaches that the continuous gaseous flow fed to the reaction chamber has a temperature above 400 C (0046).
Regarding claim 9, Denton and Abatzoglou teach the process as applied to claim 1. Denton further teaches that the gas withdrawn from the reaction chamber (reactor effluent) comprises carbon nanotubes (CNTs), excess reagents, and water vapor (0047), wherein the reagents to begin with are a mixture of carbon oxides and hydrocarbons (for example, CO2 and CH4, 0045). This meets the limitation of the gas comprising carbon nanofilaments, hydrocarbon compounds, and at least one of carbon monoxide, carbon dioxide, hydrogen, and water vapor.
Regarding claim 10, Denton and Abatzoglou teach the process as applied to claim 9. Denton further teaches filtering the gas withdrawn from the reaction chamber to recover the carbon nanofilaments from the gas (0051, Fig. 1) and dehumidifying the filtered gas (condensing out of water, 0052, Fig. 1).
Regarding claim 12, Denton and Abatzoglou teach the process as applied to claim 1. Denton further teaches that the gas is withdrawn continuously from the reaction chamber (“continuous reactor effluent,” 0048, abstract).
Regarding claim 19, Denton and Abatzoglou teach the process as applied to claim 1. Abatzoglou further teaches a mean contact time of 2 seconds within the reaction chamber (0034), falling within the claimed range of 1 to 10 seconds. Abatzoglou teaches a pressure drop of the continuous gaseous flow across the bed of catalyst particles ranging from 0.05 to 0.2 atm (0033). While this falls outside the claimed range of 0.5 to 4 atm, Abatzoglou teaches that the pressure loss across the bed is a parameter that determines the successful operation of the filter (0033); therefore it would be obvious to one skilled in the art that the pressure drop is a result effective variable of the invention. Accordingly, one of ordinary skill in the art before the effective filing date of the invention would have optimized, by routine experimentation, the pressure drop in the teaching of Abatzoglou to obtain the desired balance between the head pressure and pressure loss across the bed as taught by Abatzoglou (0034) (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223). “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Therefore one skilled in the art would arrive at the claimed invention prior to the effective filing date.
Regarding claim 21, Denton teaches carbon nanofibers/nanotubes (0030, Fig. 1, 6-10), which is interpreted to meet the limitation of carbon nanofilaments, and Denton and Abatzoglou teach the process as applied to claim 1.
Regarding claim 140, Denton and Abatzoglou teach the process as applied to claim 3. Denton teaches that the hydrocarbon compound comprises carbon (methane, which comprises carbon, 0061, 0078) and the carbon oxide comprises carbon dioxide (carbon dioxide, 0078).
Denton does not explicitly teach the molar ratio of C/CO2 in the continuous gas flow fed to the reaction chamber being between about 0.8 and 1.2. However, Denton teaches that the molar ratio is a parameter that determines whether solid carbon will form (Fig. 2; 0054-0059); therefore Denton teaches the molar ratio as being a result effective variable of the invention. Accordingly, one of ordinary skill in the art before the effective filing date of the invention would have optimized, by routine experimentation, the molar ratio in the teaching of Denton to obtain the desired balance between carbon and carbon dioxide as taught by Denton (Figure 2) (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223). “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Therefore one skilled in the art would arrive at the claimed invention prior to the effective filing date.
Regarding claim 143, Denton and Abatzoglou teach the process as applied to claim 1. Denton further teaches a range of temperatures overlapping with the claimed range of 550 to 700 C (0046). As set forth in MPEP 2144.05, in the case where the claimed range "overlap or lie inside ranges disclosed by the prior art," a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. 1990).
Claims 13, 15, 16, and 141 are rejected under 35 U.S.C. 103 as being unpatentable over Denton and Abatzoglou, as applied to claim 1, and in further view of Reshetenko et al. 2004, Coprecipitated iron-containing catalysts (Fe-Al2O3, Fe-Co-Al2O3, Fe-Ni-Al2O3) for methane decomposition at moderate temperatures Part II. Evolution of the catalysts in reaction, Applied Catalysis A: General 270 (2004) 87–99, herein referred to as Reshetenko.
Regarding claim 13, Denton and Abatzoglou teach the process as applied to claim 1. Denton further teaches that the catalysts have catalytic sites that are principally composed of iron (0104).
Denton and Abatzoglou do not teach that the catalyst particles are iron-based and comprise at least 50 mol% of iron. However, Reshetenko teaches an analogous method for the production of carbon nanotubes from a methane decomposition (multiwall carbon nanotubes, abstract) wherein Fe-Al2O3 catalysts are used (abstract). Reshetenko teaches wherein 90 wt.% iron is present in the catalyst (Table 1) which gives a mole percentage of about 94% using the following calculations.
90/(56 g/mol Fe) = 1.6; 10/(102 g/mol Al2O3) = 0.098
1.61/(1.6+0.098) = 0.942 ≈ 94%
It would be obvious to one skilled in the art to combine the teachings of Denton, Abatzoglou, and Reshetenko, and thus arrive at the claimed invention. One would be motivated to do so because Reshetenko teaches that Fe-Al2O3 catalysts are “shown to be very efficient in carbon deposition during methane decomposition” (abstract).
Regarding claim 15, Denton and Abatzoglou teach the process as applied to claim 1. Denton and Abatzoglou do not teach that the catalyst particles comprise Fe/A12O3 including at least 10 wt.% of iron within the catalyst particles. However, Reshetenko teaches an analogous method for the production of carbon nanotubes (abstract) wherein 90 wt.% iron is present in the catalyst (Table 1).
It would be obvious to one skilled in the art to combine the teachings of Denton, Abatzoglou, and Reshetenko, and thus arrive at the claimed invention. One would be motivated to do so because Reshetenko teaches that Fe-Al2O3 catalysts are “shown to be very efficient in carbon deposition during methane decomposition” (abstract).
Regarding claim 16, Denton and Abatzoglou teach the process as applied to claim 1. Denton and Abatzoglou do not teach that the catalyst particles are smaller than about 500 microns. However, Reshetenko teaches an analogous method for the production of carbon nanotubes (abstract) wherein Fe-Al2O3 particles having a size of 20-150 nm (p. 90 col. 2) are used. It would obvious to one skilled in the art to combine the teachings of Denton, Abatzoglou, and Reshetenko, and thus arrive at the claimed invention. One would be motivated to do so because Reshetenko teaches that Fe-Al2O3 catalysts are “shown to be very efficient in carbon deposition during methane decomposition” (abstract).
Regarding claim 141, Denton and Abatzoglou teach the process as applied to claim 1. Denton and Abatzoglou do not teach that the iron-based catalyst particles further comprise nickel. However, Reshetenko teaches an analogous method for the production of carbon nanotubes (abstract) wherein nickel-doped catalysts are used to decompose methane into CNT (Table 1). It would obvious to one skilled in the art to combine the teachings of Denton, Abatzoglou, and Reshetenko, and thus arrive at the claimed invention. One would be motivated to do so because Reshetenko teaches that the addition of nickel to the Fe-Al2O3 catalyst increases the carbon capacity 2-3-fold, and sees improved lifetime and higher starting methane conversion (Section 3.1, p. 88).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Denton and Abatzoglou, as applied to claim 1, and in further view of Jeong et al. 2014, KR 20140004310 A, herein referred to as Jeong. A machine translation, as cited herein, is provided with this Office action.
Regarding claim 18, Denton and Abatzoglou teach the process as applied to claim 1. Denton and Abatzoglou do not teach heating liquid hydrocarbon compounds to a gaseous state before feeding the reaction chamber with the continuous gaseous flow containing the hydrocarbon compounds.
However, Jeong teaches an analogous method for producing carbon nanotubes (title) wherein the carbon source is a hydrocarbon gas, or a liquid hydrocarbon source being vaporized (0004). It would be obvious to combine the teachings of Denton, Abatzoglou, and Jeong; one skilled in the art would recognize the suitability of a liquid hydrocarbon for the use of the formation of carbon nanotubes, as evidenced by Jeong; the courts have held that the selection of a known material based on its suitability for its intended use supports a prima facie obviousness determination; see MPEP 2144.07, Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945). Therefore one skilled in the art would arrive at the claimed invention prior to the effective filing date.
Claim 142 is rejected under 35 U.S.C. 103 as being unpatentable over Denton and Abatzoglou, as applied to claim 1, and in further view of Son et al. 2019, US 20190002285 A1, herein referred to as Son.
Regarding claim 142, Denton and Abatzoglou teach the process as applied to claim 1. Denton and Abatzoglou do not teach that the catalyst particles have a diameter between about 150 microns and about 500 microns. However, Son teaches an analogous method for producing carbon nanotubes (title) wherein the catalyst support particles have a diameter between about 100 μm to 2000 μm (0047). It would be obvious to combine the teachings of Denton and Abatzoglou and Son; one would be motivated to do so because Son teaches that when the support has a diameter of 100 μm or more, the support tends to be stably supported in the reaction tube and to flow efficiently, and the support and the carbon nanotubes tend to be easily separated from the same reaction tube, and, when the diameter of the support is 2000 μm or less, the support tends to flow easily (0047). Therefore one skilled in the art would arrive at the claimed invention prior to the effective filing date.
Conclusion
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/Eileen Moudou/Examiner, Art Unit 1738
/MICHAEL FORREST/Primary Examiner, Art Unit 1738
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