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 traverse of the restriction requirement has been considered but is not persuasive.
Applicant argues that Group II can be searched and examined without serious burden because art relevant to the method of Group II would naturally be encountered during examination of the reactor claims of Group I. However, the mere possibility that some prior art may be relevant to both inventions does not establish that examination of both inventions would impose no serious burden. The inventions require examination of different statutory subject matter and different scopes of prior-art inquiry. Group I, claims 1–10, is directed to a reactor, including particular reactor construction, FeCrAl surface/oxidation-film/carbon-layer features, heating arrangements, reaction zones, and catalyst features. Group II, claim 11, is directed to a method for producing ethylene, requiring examination of the process steps and operating conditions recited therein. The system of Group I, can be used in a different process. Accordingly, examination of Group II would require an additional search and examination directed to the claimed process beyond that required for the elected apparatus invention.
Applicant further argues that because claim 11 depends from claims identified in Group I, withdrawal of claim 11 would not reduce examination burden and claim 11 would be subject to rejoinder upon allowance of claim 1. This argument is not persuasive. The possibility of later rejoinder does not negate an otherwise proper restriction requirement. Rejoinder is considered when the conditions for rejoinder are satisfied; it does not require examination of a presently non-elected invention merely because that invention may later become eligible for rejoinder. The requirement is still deemed proper and is therefore made FINAL.
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 1-3 are rejected under 35 U.S.C. § 103 as being unpatentable over Yun et al. (US 2021/0309589 A1, hereinafter “Yun”) in view of Jönsson et al. (US 2019/0106774 A1, hereinafter “Jönsson”).
Regarding claim 1, Yun teaches a reactor for direct non-oxidative pyrolysis/conversion of methane comprising a reactor for receiving methane-containing feed and a reaction region wherein the methane-containing feed is reacted at high temperature to produce valuable hydrocarbons, including ethylene and acetylene (¶¶ [0013]–[0019], [0044]–[0048], [0068]–[0070]; Fig. 1). Yun teaches introducing methane-containing gas into the reactor, heating the reaction zone, and producing products including ethane, ethylene, and acetylene (¶¶ [0068]–[0070]). Yun further teaches that the reactor tubes, or the surfaces thereof, may comprise a coke-resistant iron-chromium-aluminum (FeCrAl) alloy (¶¶ [0049]–[0052]; claim 2), and that FeCrAl itself can serve as a catalytic surface for the direct non-oxidative methane coupling reaction. Yun operates the methane pyrolysis reaction at about 900–1300°C, preferably about 1050–1150°C. Yun further teaches that coke (carbon layer) is generated during the high-temperature non-oxidative methane reaction, including a reactor zone in which a large amount of coke is generated (¶¶ [0007], [0044]).
Yun does not expressly teach an oxidation film formed on the inner surface of the FeCrAl alloy.
Jönsson teaches FeCrAl alloys containing Fe, Cr, and Al and expressly teaches that FeCrAl alloys are well known for their ability to form protective α-alumina (Al₂O₃) oxidation scales when exposed to high temperatures of about 900-1300°C. ([0002], [0003], and [0050].
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 FeCrAl inner surface of Yun with the protective oxidation film taught by Jönsson in order to provide the known high-temperature protective and oxidation-resistant surface for the FeCrAl reactor. Upon carrying out Yun's non-oxidative methane-conversion reaction in the thus-oxidized FeCrAl reactor, the coke generated/deposited on the exposed inner reactor surface would necessarily form a carbon layer on the surface of the oxidation film, thereby yielding the claimed FeCrAl/oxidation-film/carbon-layer structure.
This interpretation of “carbon layer” is also consistent with Applicant's disclosure, which expressly states that the carbon layer “may be a coke layer formed by directly converting methane” in the reactor. Present specification ¶ [0065].
Regarding claim 2, Jönsson expressly teaches that the protective oxide scale formed on FeCrAl is α-alumina (Al₂O₃). Thus, the combination teaches the oxidation film being an alumina film formed by oxidation of the FeCrAl surface. No further modification is required beyond that discussed for claim 1.
Regarding claim 3, Yun expressly teaches coke formation in the reactor during direct non-oxidative methane pyrolysis (¶¶ [0007], [0044]). Thus, when Yun's methane conversion is performed using the oxidized FeCrAl surface of the combination, the carbon layer deposited on the oxidation film is a coke layer formed by the oxygen-free direct conversion of methane, as claimed.
Claim 4 is rejected under 35 U.S.C. § 103 as being unpatentable over Yun in view of Jönsson as applied to claim 1 above, and further in view of Lenglet (US 5,186,815).
Yun and Jönsson do not expressly teach the claimed carbon-layer thickness of 1 μm to 1 mm. Lenglet teaches forming a coke layer on the inside wall of a high-temperature hydrocarbon cracking reactor and maintaining the coke layer at a predetermined thickness of about 0.5-4 mm, preferably about 1-3 mm, which overlaps the claimed range over 0.5-1 mm. Lenglet further teaches maintaining the coke layer at a substantially controlled thickness during operation.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to control the thickness of the carbon/coke layer formed in the modified Yun reactor within the range taught by Lenglet, including the overlapping range of 0.5-1 mm, because Lenglet teaches such thicknesses for a coke layer formed on the inner wall of a high-temperature hydrocarbon-conversion reactor and teaches controlling the coke-layer thickness during operation.
Claim 5 is rejected under 35 U.S.C. § 103 as being unpatentable over Yun in view of Jönsson as applied to claim 1 above, and further in view of Nagaki et al. (US 9,902,665 B2, hereinafter “Nagaki”).
Yun teaches heating the reaction region to the temperatures required for direct non-oxidative methane conversion but does not expressly teach heating the reaction section by one of the particular methods recited in claim 5.
Nagaki teaches high-temperature non-oxidative methane conversion and expressly teaches that a reaction zone may be heated by various means including electric heating and, particularly, resistance heating wherein heat is supplied through the reactor wall. (col. 16, lines 49-64; col. 18, lines 42-61; col. 26, lines 58-67)
It would have been obvious to one of ordinary skill in the art to employ the resistance heating taught by Nagaki to heat the reaction section of Yun because Nagaki expressly identifies resistance heating through the reactor wall as a suitable means for supplying the thermal energy required for high-temperature non-oxidative methane conversion, thereby predictably providing the heat required to carry out Yun's methane-conversion reaction.
Claim 6 is rejected under 35 U.S.C. § 103 as being unpatentable over Yun in view of Jönsson as applied to claim 1 above, and further in view of Kim et al. (US 11,028,026 B2, hereinafter “Kim”).
Yun teaches direct non-oxidative conversion of methane producing products including acetylene and ethylene, but does not teach the claimed sequential first and second reaction zones.
Kim teaches a methane-conversion reactor having a first reaction region wherein methane-containing feed is reacted to produce acetylene, followed by a second reaction region wherein the acetylene is hydrogenated to produce ethylene, thereby teaching the claimed sequential methane-to-acetylene and acetylene-to-ethylene arrangement (see claim 1 and corresponding specification). Kim further demonstrates substantial ethylene selectivity using this two-region arrangement.
It would have been obvious to one of ordinary skill in the art to configure the reaction section of Yun with the first and second reaction zones taught by Kim including providing the second reaction zone with an acetylene-hydrogenation catalyst, because Kim teaches this sequential arrangement for converting methane first to acetylene and subsequently hydrogenating the acetylene to obtain ethylene with improved ethylene production/selectivity.
Claims 7-10 are rejected under 35 U.S.C. § 103 as being unpatentable over Yun in view of Jönsson and Kim as applied to claim 6 above, and further in view of Cha et al. (KR 10-2023-0013616 A, hereinafter “Cha”).
The combination above teaches an acetylene-hydrogenation catalyst in the second reaction zone but does not teach the particular sulfur-containing-polymer-coated catalyst structure of claim 7.
Cha teaches a hydrogenation catalyst comprising a porous catalyst support, a catalyst active component supported thereon, and a sulfur-containing polymer disposed on/coating at least a portion of the surface of the porous support and catalyst component (¶¶ [0032]–[0038]). Cha teaches that addition of the sulfur-containing polymer improves product selectivity and long-term catalyst stability (¶¶ [0024]–[0025]). Cha expressly teaches application of the catalyst to selective hydrogenation of alkynes, including acetylene, to corresponding alkenes (¶ [0069]).
It would have been obvious to one of ordinary skill in the art to employ Cha's sulfur-containing-polymer-coated supported hydrogenation catalyst as the acetylene-hydrogenation catalyst in the second reaction zone of Yun/Kim because Cha expressly teaches such catalysts for selective hydrogenation of acetylene to alkene while improving product selectivity and catalyst stability.
Regarding claim 8, Cha teaches that the porous catalyst support may comprise silica, alumina, magnesia, silica-alumina, silica-magnesia, or alumina-magnesia, with alumina being preferred (¶ [0059]), thereby expressly satisfying multiple alternatives recited in claim 8.
Regarding claim 9, Cha teaches that the catalyst active component may comprise one or more of Pd, Ru, Fe, Ni, Co, Mo, Au, Ag, Cu, Ti, Ga, Ce, Al, Zn, and La, among others (¶¶ [0060]), thereby expressly satisfying the claimed active-component limitation.
Regarding claim 10, Cha teaches a sulfur-containing polymer having a polyphenylene sulfide (PPS) structure comprising phenylene groups linked through sulfur atoms, including mixed meta- and para-phenylene PPS structures (¶ [0054]), thereby satisfying at least the Chemical Formula 2 alternative of claim 10. Cha further synthesizes m,p-PPS (¶¶ [0072]–[0076]) and prepares PPS/Pd/α-Al₂O₃ catalysts by applying the PPS polymer to Pd/α-Al₂O₃ (¶¶ [0100]–[0104]). Cha then employs these PPS/Pd/α-Al₂O₃ catalysts for selective acetylene hydrogenation and reports increased ethylene selectivity relative to unmodified Pd/α-Al₂O₃ (¶¶ [0116]–[0124]).
It would have been obvious to select the expressly disclosed support materials, active-metal components, and PPS sulfur-containing polymer of Cha for the acetylene-hydrogenation catalyst incorporated into the second reaction zone for the reasons discussed with respect to claim 7, namely, to provide selective acetylene hydrogenation with improved product selectivity and catalyst stability.
Conclusion
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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/TAM M NGUYEN/Primary Examiner, Art Unit 1771
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