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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 21 April 2026 has been entered.
Response to Amendment
Applicant’s amendments filed 21 April 2026 have been considered. It is acknowledged that claims 1, 4, and 6 have been amended, and claim 3 has been cancelled by Applicant. Accordingly, claims 1 and 4-6 are under full consideration.
Response to Arguments
Applicant's arguments filed 21 April 2026 have been fully considered but they are not persuasive. The respective arguments are addressed below.
In response to applicant's arguments against the references individually, specifically regarding the second heat exchanger, preheating the source material, and preheating of the feed supplied to the desulfurizer, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
In response to Applicant’s argument that “Selstam does not disclose preheating of the source material supplied to the reactor using plasma”, it is noted that the features upon which applicant relies (i.e., preheating using plasma) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
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 and 4-6 are rejected under 35 U.S.C. 103 as being unpatentable over Selstam et al. (US-20140364517-A1), hereinafter “Selstam” in view of Kim et al. (US-20100254893-A1), hereinafter “Kim”.
Regarding Claim 1, Selstam discloses an apparatus for producing a hydrogen gas (reactor to convert a portion of the syngas to CO2 and H2; see [0012]), the apparatus comprising: a plasma reactor configured to generate a hydrogen containing gas from a hydrocarbon containing gas through plasma based pyrolysis (pyrolyzing a carbon source by plasma to form a syngas; see [0012]); a separator configured to separate a hydrogen gas from the hydrogen containing gas (H2- may be separated from CO and/or CO2 produced by gasifier 104; see [0057]); and a second heat exchanger (heat exchanger 106; see [0042]) configured to obtain heat from the hydrogen gas separated by the separator (if the temperature of the synthesis gas leaving the gasifier is high enough, a heat exchanger 106 may be used to generate electrical energy or supply heat for producing steam and to produce a cooled syngas feed; see [0042] and Fig. 1 Part 106). Selstam disclosed the option to separate H2 from the syngas exiting the gasifier (see [0057]), therefore it would have been understood by a person of ordinary skill in the art that the gas entering the heat exchanger could be H2 in the case that hydrogen is separated from CO and/or CO2.
Selstam does not explicitly teach a desulfurizer. However, Kim discloses a desulfurizer configured to desulfurize a hydrocarbon (desulfurizer for desulfurizing a hydrocarbon feed; see [0008]).
Selstam teaches the hot hydrogen gas (hydrogen gas of high temperature) that was separated from the syngas produced in the plasma pyrolysis gasifier to supply heat for producing steam, as explained above. Selstam further discloses mixing steam with the hydrocarbon source (see [0038]). It is therefore understood that the hydrogen gas is exchanging heat in a heat exchanger, the heat of which indirectly preheats the hydrocarbon containing gas. Selstam does not, however, explicitly teach the hydrocarbon containing gas exchanging heat in the same heat exchanger as the hydrogen gas. However, Kim discloses a heat exchanger configured to exchange heat between the desulfurized hydrocarbon containing gas at a rear end of the desulfurizer (a second heat exchanger for preheating the mixture of the desulfurized hydrocarbon feed and superheated water; see [0008]) and the reformed gas leaving the reformer (using the reformed gas discharged from the reformer; see [0008]). The reformer of Kim is analogous to the plasma pyrolysis reactor of Selstam and the instant application, and the reformed gas is therefore analogous to the hydrogen gas separated by the separator of Selstam. When modifying Selstam with Kim, it would have naturally/logically followed that the reformed gas of Kim would be analogous to the hydrogen gas of Selstam.
Selstam and Kim are both considered to be analogous to the claimed invention because they are in the same field of hydrogen production. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified Selstam by incorporating the teachings of Kim and providing a desulfurizer and preheating the hydrocarbon containing stream. Doing so, respectively, would remove sulfur compounds from the hydrocarbon feed (see Kim [0027]), and preheat the desulfurized hydrocarbons (see Kim [0024]).
Modified Selstam does not explicitly teach a first heat exchanger configured to exchange heat between the hydrocarbon containing gas at a front end of the desulfurizer and the hydrogen gas of a high temperature. However, placing a heat exchanger upstream of an impurity removal step and then placing another heat exchanger downstream of an impurity removal step is heat integration that is standard practice in the art. Chemical engineers routinely place heat exchangers before and after impurity removal steps, such as desulfurization or dehydration. This is shown by Selstam in Fig. 1, where a heat exchanger (106) is disposed both upstream and downstream of a separator (108) that removes condensed water (an impurity), similar to the removal of sulfur. Selstam uses the same heat exchanger both upstream and downstream of the condensed water removal, however it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to separate the heat exchanger (106) taught by Selstam, (see In reDulberg, 289 F.2d 522, 523, 129 USPQ 348, 349 (CCPA 1961)) into two separate heat exchangers if the heating requirements of each stream cannot be met with a single exchanger. Selstam discloses use of a heat exchanger upstream of the impurity removal step, which results in this first heat exchanger preheating the hydrocarbon containing gas prior to its impurity removal. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to exchange heat with the hydrocarbon containing gas both before and after desulfurization as a matter of routine experimentation/optimization.
Regarding Claim 4, Selstam and Kim together disclose the apparatus of claim 1. Kim further discloses an adsorber configured to purify the hydrogen gas (a pressure swing absorption (PSA) unit for separated hydrogen from the converted gas; see [0008]) discharged after exchanging heat in the first heat exchanger or second heat exchanger (see Fig. 1). Including an adsorber would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention because it is a method of producing high-purity hydrogen (see Kim [0038]).
Regarding Claim 5, Selstam and Kim together disclose the apparatus of claim 4. Kim further discloses the adsorber performing pressure swing adsorption (PSA) (a pressure swing absorption (PSA) unit for separated hydrogen from the converted gas; see [0008]). Including a pressure swing adsorption unit would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention because it is a method of producing high-purity hydrogen (see Kim [0038]).
Regarding Claim 6, Selstam and Kim together disclose the apparatus of claim 4. Kim further discloses a cooler configured to cool the gas discharged after exchanging heat in the first heat exchanger or second heat exchanger before being introduced into the adsorber (the gas discharged… is cooled… by the fourth heat exchanger… and is then introduced into the PSA unit; see [0037]). Cooling the gas before introducing it to the PSA unit would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention because it would have brough the gas down to the temperature of the PSA unit (see Kim [0037]). Selstam further discloses a compressor (see [0045]) configured to compress gas cooled by a cooler (heat exchanger located between the two compressors to remove heat and cool syngas; see [0045]). Selstam states “syngas” and not “hydrogen gas”, however in the embodiment in which hydrogen is separated from the syngas, as Selstam discloses (see [0057]), it is understood that hydrogen would be present in place of the syngas.
Conclusion
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/A.L.K./Examiner, Art Unit 1774
/CLAIRE X WANG/Supervisory Patent Examiner, Art Unit 1774
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