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 .
Claim Status
The claims are not substantially amended.
Response to Arguments
Applicant's arguments filed 7/16/26 have been fully considered but they are not persuasive in-part and persuasive in-part.
The remarks argue the following on page 5:
The Office asserts McKeigue to disclose to a process for producing syngas by partial
oxidation of methane, carbon dioxide, and oxygen at high temperatures (700-1400°C), which can be performed in a non-catalytic apparatus. The process yields a product mixture includingmCO, H₂, and water, with CO2 byproduct being recycled, addressing the "additional importednCO2" limitation of the claims. Methane is used as the main hydrocarbon source. However,nMcKeigue does not specifically disclose the reactant ratios. Amin et al. is relied upon for thenoptimization of methane-to-syngas conversion through thermodynamic analysis of temperature,npressure, and specifically the feed ratios of CH4:CO2:O₂. Amin shows that adjusting these ratios and reaction temperature directly impacts the H2/CO ratio in the syngas. Given these teachings, the Office concludes it would have been obvious for a person skilled in the art to combine McKeigue's process with Amin's optimization strategy, adjusting the reactant ratios and temperature to achieve a desired H2/CO ratio in the syngas. Applicants disagree for at least the following reasons.
Initially, Applicants note (as also noted in the international preliminary examination) that equation (II) in paragraph [0038] of McKeigue implies a equimolar ratio of oxygen to hydrocarbons to produce a syngas having molar ratio hydrogen to carbon monoxide of 1:1. Equation (II) in paragraph [0038] of McKeigue furthermore implies a molar ratio methane : oxygen : carbon dioxide of 0.5 : 0.25 : 0.25 that is clearly outside the molar ratio as defined in the claims.
The remarks are respectfully not persuasive. It was recognized in the prior action that McKeigue does not disclose the claimed ratio. Amin however explains that basic variation between CH4:CO2:O2 ratio and temperature differ greatly, such that when the reaction temperature, pressure and feed ratios are adjusted, different results were obtained. For example, at a temperature range of 1,000K and below, the H2/CO ratio varies from 0.8 to 3.5 (page 1794, right col, para. 1), while at a temperature range above that, the H2/CO ratio narrows to about 1-1.7 (page 1794, right col, para. 1). Other factors effecting the H2/CO ratio include the initial ratio of reactants (page 1796, left col, para. 1-2). In tests, Amin shows that the ratio of H2/CO increases with increased temperature (see Table 3). As to the ratio of reactants, Amin explains that a ratio of CH4:CO2:O2 ranging from 1-0.8: 1-0.2: 1-0.2 of these reactants is effective at a minimum temperature range of 1,000K (abstract).
Next, the remarks argue the following:
With respect to Ashcroft, the Office asserts that Ashcroft teaches a feed composition comprising a ratio CH4 : CO2 : O2 of 64 : 3.5 : 32 to achieve a H2 : CO yield of 89% : 86%. However, the ratio is outside the molar ratio methane : oxygen : carbon dioxide of 0.39 to 0.57 : 0.30 to 0.40 (0.31 to 0.38) : 0.05 to 0.30 defined in claims 15 and 21.
Even if the Office maintains the view that the cited references set forth a prima facie case of obviousness, Applicants have evidence to rebut such showing. A prima facie case of obviousness is rebuttable by proof that the claimed invention possesses unexpectedly advantageous or superior properties. In re Papesch, 315 F.2d 381 (CCPA 1963). Applicants submit that the pending claims are non-obvious and patentable over the cited combinations of references because the presently claimed process yields unexpected results. The results achieve the direct production of synthesis gas with a tunable H2/CO ratio, particularly the industrially important 1:1 ratio, by noncatalytic partial oxidation of hydrocarbons (preferably methane) in the presence of both recycled and imported CO2 at high temperature (1200-1550°C). This process physically utilizes carbon-containing by-product streams and imported CO₂, acting as a CO2 sink and reducing overall emissions, in contrast to conventional methods that thermally dispose of these streams, releasing more CO2. The data in the specification and tables show that, by adjusting the hydrocarbon/CO2/O₂ feed ratios and operating conditions, the process consistently achieves nearly complete methane conversion (methane slip <1.5% by volume, often <0.2% or even <0.05%) and enables direct, high-yield production of syngas with the desired H2/CO ratio and significant imported CO2 uptake (up to 0.30 t CO2 per t syngas for methane feed). For at least these reasons, Applicants respectfully submit that the instant rejections cannot be maintained and must be withdrawn.
The remarks with respect to Claim 21 are persuasive and therefore this claim is allowed.
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.
Claim(s) 15, 16, 17, 18, 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over McKeigue (US Pub.: 2008/0305030) and in view of Amin et al. “Thermodynamic Equilibrium Analysis of Combined Carbon Dioxide reforming with Partial Oxidation of Methane to Syngas”.
McKeigue describes a process for partial oxidation (abstract) of methane, CO2 and oxygen (para. 38, equation II) for making a syngas product (para. 37, 38). The conversion can be performed in a non-catalytic partial oxidation apparatus (para. 47). The reaction is performed at a temperature range of 700-1400 degrees C (para. 39). The product made can include CO, H2 and water (see equation II at para. 38). Additionally, McKeigue teaches that there may be CO2 byproduct (para. 37 and 41), which is removed and recycled (para. 37). This recycled CO2 stream can be considered “additional imported CO2” of Claim 15. The starting composition is methane (see equations II, III, IV). This can be considered about 100% of the hydrocarbon source.
As to the ratios, McKeigue does not disclose these features.
Amin describes a methane to syngas conversion process (see page 1789, right col, last line). In the background, Amin states that current research studies on the conversion of methane to syngas have certain shortfalls, particularly, one of their focuses is on the catalyst efficiency (page 1790, left col, para. 2) and that the basic variables between CH4:CO2:O2 ratio and temperature differ greatly and the results are hardly comparable (page 1790, left col, para. 2). As a solution to this, Amin analyzes the thermodynamics of the temperature, pressure and feed ratio on the equilibrium composition and conversion of the reactants (page 1790, left col, para. 2). Particularly, the analysis is with respect to the feed ratio of between CH4:CO2:O2 (page 1790, left col, para. 3) and the total Gibbs energy minimization of the system (page 1790, left col. para. 3) and how it can be used to optimize the desired H2/CO ratio (page 1790, left col, para. 3).
The chemical species employed for the reaction includes CO2, O2, CH4 and H2O (page 1791, left col, last line to right col, line 1). The ratio of H2:CO (syngas) varies based on the temperature (page 1794, right col, para. 1). At a temperature range of 1,000K and below, the H2/CO ratio varies from 0.8 to 3.5 (page 1794, right col, para. 1), while at a temperature range above that, the H2/CO ratio narrows to about 1-1.7 (page 1794, right col, para. 1). Other factors effecting the H2/CO ratio include the initial ratio of reactants (page 1796, left col, para. 1-2). In tests, Amin shows that the ratio of H2/CO increases with increased temperature (see Table 3). As to the ratio of reactants, Amin explains that a ratio of CH4:CO2:O2 ranging from 1-0.8: 1-0.2: 1-0.2 of these reactants is effective at a minimum temperature range of 1,000K (abstract). Since the temperature is a minimum and Amin teaches that the H2/CO ratio can be adjusted so that a higher temperature results in a higher H2/CO ratio, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to increase the temperature of the reaction in order to increase the ratio of H2/CO in the produced synthesis gas.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the syngas produced by adjusting the H2/CO ratio by adjusting the ratio of the reactants, to include feeding a ratio of CH4:CO2:O2 ranging from 1-0.8: 1-0.2: 1-0.2, as taught by Amin for use in the production of syn gas, as taught by McKeigue because adjusting these reactants in this range is known to produce syngas product with an optimizable ratio of H2/CO.
Claim(s) 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over McKeigue and Amine as applied to claim 15 above, and further in view of Fong (US Pat.: 5496859).
The references do not teach that the methane stream includes oxygenates.
Fong describes a gasification process for producing syngas (title) using partial oxidizing reaction with methane (abstract). Fong explains that the process can be combined with a oxygenated reforming step to produce methanol (col. 2, lines 8-11). In the process of Fong, the reactor feed methane and an oxygenate into a gasifier (col. 4, lines 29-30), which includes a partially recycled stream 7 (see Fig. 1).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a mixed methane and methane stream for use in making syngas, as taught by Fong for use in the process of McKeigue and Amine because Fong explains that it is known to isolate methane from a mixed methane and methanol stream for use in making a syngas.
Claim(s) 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over McKeigue and Amine as applied to claim 15 above, and further in view of Steele (US Pub.: 2015/0060335).
The references do not teach inclusion of oxygenates.
Steele describes a gasification means of hydrocarbon (abstract). The system can obtain a a stream of hydrocarbon that can be a mixture of methane and methanol (para. 79). The methane can be separated from the methanol and then gasified (para. 79). The methane can also be converted into syngas by further processing (abstract).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to obtain a methane stream that is a mixture of methane and methanol, as taught by Steele for use with the process of McKeigue and Amine because Steele explains that it is known to isolate methane from an oxygenate and methane source for further processing of methane in the manufacture of synthesis gas.
Allowable Subject Matter
Claim 21 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is an examiner’s statement of reasons for allowance: Amin describes methane, oxygen and CO2 ratios that are outside the range of Claim 21. Also, Ashcroft also discloses a ratio of methane, oxygen and CO2 that are also outside the range of Claim 21.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Conclusion
THIS ACTION IS MADE FINAL. 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 SHENG HAN DAVIS whose telephone number is (571)270-5823. The examiner can normally be reached 9-5:30.
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/SHENG H DAVIS/Primary Examiner, Art Unit 1732 August 19, 2026
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