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 Objections
The claims are objected to because of the following informalities:
Regarding Claim 1 and 14, the phrase “first process stream originates a second feed stream”, while reasonably clear, could be reworded to better convey the invention as indicated in the specification. It is recommended that the term “originates” be replaced – the following recommended language is set forth: “…the first process stream is provided as a second feed stream…”
Regarding Claims 6 and 8, the claims recite “…stream also comprises CO, H2, N2, CH4…”. This phrase lacks a conjunction linking the list of components and is therefore grammatically incorrect. In light of this, the claim should be amended to include a conjunction, e.g., “CO, H2, N2, and/or CH4.”
Regarding Claim 11, the word “electrically” in “electrically heating” should be corrected to “electrical”.
Regarding Claim 14, for grammatical clarity, it is recommended the claim be re-worded as follows: “…is arranged upstream [[to]] of at least one reformer…to a hydrogen rich first process stream in thethe first process stream…to a carbon monoxide rich second process stream in the reformer…which enters back into the
Regarding Claim 15, the claim should be corrected as follows: “A plant according to Claim 14, [[.]] wherein…”
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 3-6, 8-9, 12 rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding Claims 3-5, it is unclear what is meant by “…further comprises a carbon dioxide rich stream…” It is unclear how one stream, i.e., the first or second feed stream, may “further comprise” another stream. While Claim 1 requires mixing at least one of the first feed stream or the first process stream with a CO2-rich stream, Claims 3-5 do not pertain to limitations relating to such mixing. Therefore, the limitation renders the claim indefinite, as it is unclear whether the claim means to limit the actual composition of the CO2 supplied to the mixing step, or whether the claim means to limit the actual composition of CO2 in these streams. For purposes of examination, the claims will be interpreted as limiting the actual composition of CO2 in the first and second feed streams. The terms “the first carbon dioxide rich stream” and “the second carbon dioxide rich stream” as recited in Claim 5 will be interpreted as referring to the mol% of CO2 in the first feed stream and the second feed stream respectively.
Regarding Claims 3-5, a broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, Claim 3 recites the broad recitation at up to 100 mol% (i.e., < 100 mol%), and the claim also recites at least 98 mol%, which is the narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims. For purposes of examination, the examiner will interpret the claim according to its broadest reasonable interpretation, i.e., < 100 mol% CO2, or in other words, simply comprising CO2.
Regarding Claims 8 and 9, the claims recite “…via splitting a carbon import stream between CO2 rich streams.” Notably, the claim refers to a plural number of CO2 rich streams, whereas Claim 1, on which Claims 8 and 9 depend, only require “a CO2 rich stream”, i.e., one or more CO2 rich streams. It is therefore not clear what CO2 rich streams are being referred to in the claims. For purposes of examination, the examiner will interpret the claim as referring to the configuration described in Claim 5, in which two CO2 rich streams are required.
Regarding Claim 12, the claim recites the limitation "the…air streams". There is insufficient antecedent basis for this limitation in the claim. For purposes of examination, since neither the instant claims nor the specification make any reference to such “air streams”, the claim will be interpreted as only referring to “…a residual enthalpy in the synthesis gas…”
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.
Claim(s) 1-4, 10-11, 13-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over US20200095124A1, hereinafter ‘Rueger’.
Regarding Claim 1, Rueger discloses a method for producing synthesis gas comprising CO (Figs. 6 and 7: synthesis gas is produced comprising CO), comprising the following steps:
a first feed stream comprising steam and hydrogen is partially converted to a hydrogen rich first process stream by electrolysis (Fig. 1, [0093]-[0096]: steam (1), H2/CO-containing cathode purge gas (32) and CO2 (2) are mixed in a gas mixer 4. This gas mixture after thermal treatment results in gas stream (8), which is supplied to an electrolysis stack (9), where electrolytic splitting of the gas to H2, CO and O2 is carried out by electric energy (10) – the hot gas accumulating at the cathode contains H2, CO, unreacted steam, and CO2 as well as formed methane. This resulting cathode stream is considered a hydrogen-rich stream as claimed);
first process stream originates a second feed stream which is converted to a CO rich second process stream in a reforming step ([0097]: after further preheating and treatment, the gas stream resulting from electrolysis is supplied to a catalytic reactor (20) and reforming is performed (reaction R4), producing a CO-rich stream as claimed); and
said second process stream comprising CO rich syngas and steam is cooled, providing another stream comprising steam ([0099]: after cooling of the reaction gas (25) in the recuperator (6), steam (28) which is unreacted or is formed by the chemical reaction R3 in the electrolysis stack (9) and condensed by the cooling (6) and (26) is discharged from condensation vessel (27) via the condensate removal (29)),
wherein the molar H2 to CO ratio in said second process stream is below 4.5 (Table 1: the composition of the produced synthesis gas is disclosed, with the ratio of H2:CO in all trials reported as below 4.5), and
wherein at least one of i) first feed stream or ii) first process stream is mixed with a CO2 rich stream (Fig. 1, [0093]-[0096]: steam (1), H2/CO-containing cathode purge gas (32) and CO2 (2), considered a CO2-rich stream, are mixed in a gas mixer 4).
Further regarding Claim 1, Rueger does not disclose that the another stream comprising steam enters said first feed stream.
However, it is evident that the recovered condensate in Rueger would be primarily water ([0099]: after cooling of the reaction gas (25) in the recuperator (6), steam (28) which is unreacted or is formed by the chemical reaction R3 in the electrolysis stack (9) and condensed by the cooling (6) and (26) is discharged from condensation vessel (27) via the condensate removal (29)). Further, the feed of Rueger requires steam, as discussed above.
Further, Rueger discloses that the inventive process may comprise the reuse of excess reagents generated within the process – for example, Rueger discloses that when excess hydrogen is utilized in the instant process, hydrogen or a hydrogen-enriched gas is separated from the synthesis gas after the final cooling and condensate separation, and is recirculated by means of the compressor, and together with the steam and the CO 2 is returned to the process ([0122]). Rueger further details prior art processes that apply similar recirculation principles ([0026]).
In light of this, given the feed to the process of Rueger requires steam, and given that the process of Rueger also produces excess unused water, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to integrate a recirculation mechanism to provide water condensed from the synthesis gas to the first feed stream, thereby reducing the water duty of the process. Such recirculation is routinely performed in the art to reduce process waste, and Rueger already incorporates recirculation of other reagents to achieve this goal.
Regarding Claim 2, Rueger discloses that the first feed stream further comprises CO (Fig. 1, [0093]-[0096]: steam (1), H2/CO-containing cathode purge gas (32) and CO2 (2) are mixed in a gas mixer 4).
Regarding Claim 3, Rueger discloses the first feed stream further comprises a carbon dioxide rich stream which comprises up to 100 mol% CO2 (Fig. 1, [0093]-[0096]: steam (1), H2/CO-containing cathode purge gas (32) and CO2 (2) are mixed in a gas mixer (4) – absent disclosure to the contrary, the CO2 stream (2) is considered pure CO2, or is otherwise a stream of CO2 having up to 100 mol% CO2).
Regarding Claim 4, Rueger discloses the second feed stream further comprises a carbon dioxide rich stream which comprises up to 100 mol% CO2 (Fig. 1, [0093]-[0096]: steam (1), H2/CO-containing cathode purge gas (32) and CO2 (2) are mixed in a gas mixer (4), and are subsequently electrolyzed. Given the presence of CO2 in the feed, there would necessarily exist an amount of CO2 in the second feed stream, such that it is considered a stream of CO2 having up to 100 mol% CO2).
Regarding Claim 10, Rueger discloses said first process stream, when exiting the electrolyzer, has a temperature from approximately 600 to 1000° C ([0032]: the produced gas from the electrolyzer is about 850 °C),
which is lower than the temperature of said second process stream when exiting the reformer, of approximately 850 to 1200° C ([0037]: the desired final reaction temperature of the reforming step is about 950 °C, which is also the approximate temperature at which the reactants would exit the reactor, and which is higher than the temperature of the first process stream exiting the electrolyzer).
Regarding Claim 11, Rueger discloses the first feed stream and the second feed stream are heated by means of electrically heating, condensing steam, gas heated heat exchangers, or a combination thereof (Fig. 1: the hot gas resulting from the reforming step (25) is passed through a recuperating heat exchanger (6) wherein the exchange of heat would heat the first feed stream, and further an electrical heater (7); the outlet of the electrolyzer (18) is passed through an electrical heater (19)).
Regarding Claim 13, Rueger discloses part of the generated syngas is recycled back into the first feed stream to a solid oxide electrolysis cell (Fig. 1: the figure shows a portion of synthesis gas (30) being recycled back into the first feed stream; [0045]: the electrolyzer stack is an SOEC, or a solid oxide electrolysis cell).
Regarding Claim 14, Rueger discloses a plant for producing synthesis gas comprising CO, wherein at least one electrolyzer is arranged upstream to at least one reformer (Figs. 6 and 7: synthesis gas is produced comprising CO; Fig. 1: an electrolyzer is arranged upstream from a reformer), such that:
a) a first feed stream comprising steam and hydrogen is partially converted to a hydrogen rich first process stream in the electrolyzer (Fig. 1, [0093]-[0096]: steam (1), H2/CO-containing cathode purge gas (32) and CO2 (2) are mixed in a gas mixer 4. This gas mixture after thermal treatment results in gas stream (8), which is supplied to an electrolysis stack (9), where electrolytic splitting of the gas to H2, CO and O2 is carried out by electric energy (10) – the hot gas accumulating at the cathode contains H2, CO, unreacted steam, and CO2 as well as formed methane. This resulting cathode stream is considered a hydrogen-rich stream as claimed);
b) a first process stream originates a second feed stream which is converted to a carbon monoxide rich second process stream in the reformer ([0097]: after further preheating and treatment, the gas stream resulting from electrolysis is supplied to a catalytic reactor (20) and reforming is performed (reaction R4), producing a CO-rich stream as claimed); and
c) said second process stream comprising carbon monoxide rich syngas and steam is cooled in a heat exchanger, providing another stream comprising steam ([0099]: after cooling of the reaction gas (25) in the recuperator (6), steam (28) which is unreacted or is formed by the chemical reaction R3 in the electrolysis stack (9) and condensed by the cooling (6) and (26) is discharged from condensation vessel (27) via the condensate removal (29)),
wherein at least one of i) first feed stream or ii) first process stream is mixed with a CO2 rich stream (Fig. 1, [0093]-[0096]: steam (1), H2/CO-containing cathode purge gas (32) and CO2 (2), considered a CO2-rich stream, are mixed in a gas mixer 4).
Further regarding Claim 14, Rueger does not disclose that the another stream comprising steam enters back into the electrolyzer.
However, it is evident that the recovered condensate in Rueger would be primarily water ([0099]: after cooling of the reaction gas (25) in the recuperator (6), steam (28) which is unreacted or is formed by the chemical reaction R3 in the electrolysis stack (9) and condensed by the cooling (6) and (26) is discharged from condensation vessel (27) via the condensate removal (29)). Further, the feed to the electrolyzer of Rueger requires steam, as discussed above.
Further, Rueger discloses that the inventive process may comprise the reuse of excess reagents generated within the process – for example, Rueger discloses that when excess hydrogen is utilized in the instant process, hydrogen or a hydrogen-enriched gas is separated from the synthesis gas after the final cooling and condensate separation, and is recirculated by means of the compressor, and together with the steam and the CO2 is returned to the process ([0122]). Rueger further details other prior art processes that apply similar recirculation principles ([0026]).
In light of this, given the feed to the process of Rueger requires steam, and given that the process of Rueger also produces excess unused water, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to integrate a recirculation mechanism to provide water condensed from the synthesis gas back to the electrolyzer, thereby reducing the water duty of the process. Such recirculation is routinely performed in the art to reduce process waste, and Rueger already incorporates recirculation of other reagents to achieve this goal.
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over US20200095124A1, hereinafter ‘Rueger’, in view of US20080241059A1, hereinafter ‘Peng’.
Regarding Claim 15, Rueger discloses the electrolyzer is solid oxide electrolysis cell, and that reformer is an eSMR ([0045]: the electrolyzer stack is an SOEC, or a solid oxide electrolysis cell; [0037]-[0038]: also useful and conceivable are other heater-reactor variants, such as a reactor bed continuously heated with electric energy in order to obtain the desired final reaction temperature – this is considered an eSMR reactor, or electric steam methane reforming reactor, as it utilizes electrical energy. In light of this passage of Rueger, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to utilize an eSMR reactor within the process of Rueger).
However, Rueger does not disclose that the heat exchanger is a boiler.
Peng discloses a method for generating hydrogen in a production facility having a catalytic steam reformer (Abstract). A person of ordinary skill in the art would have recognized Peng as analogous to Rueger, as both references are drawn to the same field of endeavor as the claimed invention, steam reforming to produce hydrogen - a reference is analogous art to the claimed invention if the reference is from the same field of endeavor as the claimed invention, In re Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212.
Further, Peng discloses passing the reformed gas mixture or a portion of the reformed gas mixture from the reformer into a boiler to form a boiler effluent from the reformed gas mixture and to generate steam from a liquid water-containing feed ([0013]). The steam that is generated in said boiler may be used to form the reformer feed gas mixture and/or used elsewhere in the production facility and/or exported ([0045]). Notably, the first process feed of Rueger requires steam, and the use of such a boiler as described in Peng would allow for waste heat in the reformed gas outlet to be reused in generating steam for the process, thereby reducing the heat duty of the process.
Accordingly, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to utilize a boiler such as that disclosed in Peng within the process of Rueger. The use of such a boiler would reduce the heat duty of the process, thereby making the process more energy efficient and more cost effective.
Claim(s) 6-9, 12, 16-18, 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over US20200095124A1, hereinafter ‘Rueger’, in view of WO2020208008A1, hereinafter ‘Sarkar’.
Regarding Claims 6-9, while Ruger discloses a plant for producing synthesis gas including a reverse water gas shift (rWGS) reaction and subsequently steam reforming ([0030]-0035]), and further discloses that syngas as produced by the disclosed process is utilized in downstream synthesis of hydrocarbons such as in a Fischer-Tropsch synthesis or methanol synthesis ([0008]-[0009]), Ruger does not disclose that the second feed stream comprises CO, H2, N2, and/or CH4 via the merging of a carbon import stream with the CO2 rich stream, or that the second feed stream also comprises O2, hydrocarbons, alcohols, and/or keytones.
Sakar discloses a plant for producing hydrocarbons, comprising a syngas stage, said syngas stage comprising a methanation section and/or a reverse water gas shift (rWGS) section, and an autothermal reforming (ATR) section, and b., a synthesis stage (Page 3). Sakar discloses the hydrogen feed to the plant may be one or more electrolyzer units (Page 4). A person of ordinary skill in the art would have recognized Sakar as analogous to Rueger, as both references are drawn to the same field of endeavor as the claimed invention, the - a reference is analogous art to the claimed invention if the reference is from the same field of endeavor as the claimed invention, In re Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212. Both the electrolyzing (i.e., rWGS) and reforming steps of Rueger are analogous to the “syngas stage” as disclosed in Sakar.
Further, Sakar discloses that a hydrocarbon-containing off-gas stream from the synthesis stage may be fed to the syngas stage as a fourth feed containing hydrocarbons. The source of the fourth feed can be part or all of a stream comprising hydrocarbons produced in the hydrocarbon synthesis stage. The fourth feed may additionally comprise other components such as CO2 and/or CO and/or H2 and/or steam and/or other components such as nitrogen and/or argon. See Page 5, lines 18-32. Some non-exhaustive examples of possible sources of fourth feeds and corresponding synthesis stages are provided in the table on Page 6, including hydrocarbon sources resulting from Fischer-Tropsch (FT) and methanol production processes. Sakar further discloses that a number of recycle streams may be added to various points of the synthesis gas stage, either mixed or added separately, and may comprise several separate or mixed streams.
Therefore, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to incorporate a synthesis stage to the process of Rueger, including converting the syngas produced by the reformer of Rueger into hydrocarbons, such as by Fischer-Tropsch (FT) or methanol synthesis, thereby producing valuable products for sale. Further, it would be obvious to utilize a fourth feed resulting from said synthesis as described by Sakar, that is, a hydrocarbon-containing off-gas stream from the synthesis stage which may be fed to the syngas stage as a fourth feed containing hydrocarbons, CO2, CO, H2, steam, nitrogen, and/or argon. The use of such a fourth stream would reduce process waste by reusing process off-gas, which would thereby increase the yield and economics of the process of Rueger.
Regarding Claim 12, Rueger discloses part of a residual enthalpy in the synthesis gas and air streams is recuperated (Fig. 1: the hot gas, i.e., the synthesis gas, resulting from the reforming step (25) is passed through a recuperating heat exchanger (6) wherein the recuperator would recuperate a portion of the residual enthalpy in the synthesis gas), and
the second process stream comprising syngas and steam is cooled down, the nonconverted water being condensed and reused (as discussed above, the process of Reuger suggests reusing water collected after cooling and condensing the product stream of the reformer).
Further regarding Claim 12, with regard to the language ‘…to be used in a downstream synthesis…’, it is noted that this phrase is drawn to intended use. Limitations based on the intended use do not confer patentability if the prior art is capable of performing the same function — see MPEP 2111.02(II). In the instant case, Reuger discloses that heat is recuperated, and provides a recuperator for doing so, and further discloses downstream synthesis as discussed above. Therefore, the process taught by Rueger as modified above is commensurately capable of providing for such intended uses in as much as recited and required herein, and therefore meets this intended use limitation as claimed.
Further regarding Claim 12, Rueger as modified above is silent regarding the second process stream comprising syngas and steam is cooled down approximately to room temperature.
However, the object of cooling in Rueger , as discussed above, is to condense and remove unused and unreacted water in the syngas stream. Such condensation is governed by vapor/liquid equilibrium phenomena, i.e., the dew point. Because the saturation vapor pressure of water is a function of temperature, temperature directly and predictably determines the equilibrium water partial pressure, and the degree to which water condenses from the syngas stream.
Therefore, as the degree of water condensation is a variable that can be modified, among others, by adjusting the cooling temperature, the precise amount would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed range cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the cooling temperature in Rueger to obtain the desired degree of water condensation, 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).
Regarding Claim 16, Rueger as modified above makes obvious the incorporation of a hydrocarbon synthesis stage downstream from the production of syngas, as discussed above.
Regarding Claim 17, Rueger as modified above makes obvious the incorporation of a hydrocarbon synthesis stage downstream from the production of syngas, wherein the hydrocarbon synthesis is a FT synthesis, as discussed above.
Further regarding Claim 17, with regard to the language ‘for producing fuels’, it is noted that this phrase is the intended use of the claimed product. Limitations based on the intended use of a structure do not confer patentability if the prior art is capable of performing the same function — see MPEP 2111.02(II). In the instant case, FT synthesis would necessarily be capable of producing fuels in the same way as claimed. Therefore, the disclosure of Rueger as modified above is commensurately capable of providing for such intended uses in as much as recited and required herein, and therefore Rueger as modified above meets this intended use l-imitation as claimed.
Regarding Claim 18, Rueger as modified above makes obvious the incorporation of a hydrocarbon synthesis stage downstream from the production of syngas, wherein the hydrocarbon synthesis is a methanol synthesis, as discussed above.
Regarding Claim 20, Rueger as modified above makes obvious the syngas has a ratio of H2/CO in the range from 1.8 to 2.2 (as discussed above, Rueger discloses a syngas having a H2:CO ratio of 2, which falls within the claimed range).
Claim(s) 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over US20200095124A1, hereinafter ‘Rueger’, in view of WO2020208008A1, hereinafter ‘Sarkar’, and further in view of Cañete et al. (Synthesis Gas Processes for Methanol Production via CH4 Reforming with CO2, H2O, and O2, I&EC Research, 2014), hereinafter ‘Cañete’.
Regarding Claim 19, while Ruger discloses a plant for producing synthesis gas including a reverse water gas shift (rWGS) reaction and subsequently steam reforming ([0030]-0035]), and further discloses that syngas as produced by the disclosed process is utilized in downstream synthesis of hydrocarbons such as in methanol synthesis ([0008]-[0009]), Ruger does not disclose that said syngas has a module of (H2−CO2)/(CO+CO2) in the range from 1.8 to 2.2, suitable for methanol synthesis in a downstream methanol reactor system for methanol production.
However, as discussed above in the rejection of Claims 6-9, the disclosure of Sakar makes obvious adding a synthesis stage, such as methanol synthesis, downstream from the electrolyzer and reformer respectively. A particular methanol synthesis available for providing in such a configuration is described by Cañete – Cañete discloses design for the production of synthesis gas, suitable for methanol production (Abstract). Notably, Cañete discloses, based on the reactions 1 and 2 that take place to form methanol from syngas, a module M is defined as (H2−CO2)/(CO+CO2), and the optimal value for these reactions is disclosed as M = 2 (1. Introduction).
Given this, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to incorporate the methanol synthesis as disclosed by Cañete downstream of the process of Rueger as a synthesis stage, including the use of the process conditions, processing temperatures, and catalysts, particularly a value for module M of 2. Such a synthesis stage would predictably provide a means for use of the synthesis gas produced by the process of Rueger to produce salable C5+ olefins. In doing so, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to adjust the process of Rueger to ensure the produced syngas entering this synthesis stage has a composition of H2, CO2, and CO such that it has a module M of 2, disclosed as optimal by Cañete. This makes obvious the range as claimed. Further, such a syngas stream as modified herein would be suitable for methanol synthesis in a downstream methanol reactor for methanol production.
Claim(s) 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over US20200095124A1, hereinafter ‘Rueger’, in view of WO2020208008A1, hereinafter ‘Sarkar’, and further in view of Valipour et al. (Mathematical Modeling of a Non-Catalytic Gas-Solid Reaction: Hematite Pellet Reduction with Syngas, Transactions C: Chemistry and Chemical Engineering, 2009), hereinafter ‘Valipour’.
Regarding Claim 21, while Ruger discloses a plant for producing synthesis gas including a reverse water gas shift (rWGS) reaction and subsequently steam reforming ([0030]-0035]), and further discloses that syngas as produced by the disclosed process is utilized in downstream synthesis of hydrocarbons such as in methanol synthesis ([0008]-[0009]), Ruger does not disclose that said syngas has a module of (CO+H2)/(CO2+H2O)>7.5 and is suitable as a reducing agent.
However, as discussed above in the rejection of Claims 6-9, the disclosure of Sakar makes obvious adding a synthesis stage utilizing the reducing properties of the produced syngas downstream from the electrolyzer and reformer respectively.
As disclosed by Valipour, in reactions where syngas is a reactant, the module (CO + H2)/(CO2 + H2O) is known as the gas utility, or just γ. Valipour discloses that “[i]n industrial reduction processes…the gas utility may change in the range of 5 < γ < 49, depending on the gas reforming system…the effect of reducing gas utility on the reduction rate is illustrated in Figure 14. The degree of reduction is diminished as the gas utility is lowered. However, there is no significance on the reduction rate (shown in Figure 14b) when the gas utility is increased above = 15.” Therefore, it is clear that the gas utility, defined as the claimed module, is a variable that may be manipulated in order to affect the degree of reduction in using syngas as a reductant.
Therefore, as the degree of reduction in using syngas as a reductant is a variable that can be modified, among others, by adjusting the gas utility module, the precise amount would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed range cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the gas utility of the gas in Reuger as modified above to obtain the desired degree in reduction in using syngas in the downstream synthesis stage, 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).
Claim(s) 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over US20200095124A1, hereinafter ‘Rueger’, in view of WO2020208008A1, hereinafter ‘Sarkar’, and further in view of Sonal et al. (Synthesis of C5+ hydrocarbons from low H2/CO ratio syngas over silica supported bimetallic Fe-Co catalyst, Catalysis Today, 2016), hereinafter ‘Sonal’
Regarding Claim 22, while Ruger discloses a plant for producing synthesis gas including a reverse water gas shift (rWGS) reaction and subsequently steam reforming ([0030]-0035]), and further discloses that syngas as produced by the disclosed process is utilized in downstream synthesis of hydrocarbons such as in a Fischer-Tropsch synthesis ([0008]-[0009]), Ruger does not disclose that said syngas has a ratio of H2/CO < 1.5 and is suitable as a source of CO.
However, as discussed above in the rejection of Claims 6-9, the disclosure of Sakar makes obvious adding a synthesis stage, such as FT synthesis, downstream from the electrolyzer and reformer respectively. A particular FT synthesis available for providing in such a configuration is described by Sonal – Sonal discloses a FT synthesis of C5+ hydrocarbons by the reaction of syngas having a low ratio of H2:CO using a bimetallic catalyst, said catalyst including metals such as Fe, Co, and Ru (1. Introduction). Sonal defines ‘low H2/CO’ as being between 0.5-1.5 (id.). Sonal particularly discloses trials utilizing an H2/CO ratio of 1.48, and varying the molar ratio between 0.5 and 1.5 (3.2. Catalytic activity testing). Advantageously, Sonal discloses that, at 240 °C and H2/CO of 1.48, Cat-2 showed maximum CO conversion (72%) with maximum C5+(60%) selectivity.
Given this, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to incorporate the FT synthesis as disclosed by Sonal downstream of the process of Rueger as a synthesis stage, including the use of the process conditions, processing temperatures, and catalysts, particularly 240 °C, H2/CO of 1.48, and Cat-2. Such a synthesis stage would predictably provide a means for use of the synthesis gas produced by the process of Rueger to produce salable C5+ olefins. In doing so, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to utilize a low H2/CO ratio syngas as a feed to such a synthesis, and therefore would have adjusted the process of Rueger to ensure the produced syngas entering this synthesis stage has a low H2/CO ratio, such as a ratio of 1.48, as utilized by Sonal. This makes obvious the range as claimed. Further, such a syngas stream as modified herein would have the same composition as claimed, and is therefore considered a “suitable source of CO” as claimed.
Allowable Subject Matter
The following is a statement of reasons for the indication of allowable subject matter:
The prior art does not disclose or reasonably suggest the limitations of Claim 5. While the prior art identified above makes obvious a first feed stream and a second feed stream comprising carbon dioxide, the prior art does not disclose or suggest that the second feed stream would comprise more CO2 than the first feed stream. Particularly, Rueger discloses adding CO2 in the first feed stream that enters the electrolyzer, where CO2 is consumed by the rWGS reaction, but does not add additional CO2 to the electrolyzer effluent prior to its introduction to the reformer. In this process, the amount of CO2 in the second feed stream would be expected to be less than the first feed stream, and there is no motivation provided in the prior art to adjust the amount of CO2 in the second feed stream relative to the first feed stream, such that the second feed stream comprises more CO2 than the first feed stream.
Conclusion
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LOGAN LACLAIR
Examiner
Art Unit 1738
/L.E.L./ Examiner, Art Unit 1738
/ANTHONY J ZIMMER/ Supervisory Patent Examiner, Art Unit 1736