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 Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-16 are rejected under 35 U.S.C. 112(a)/1st par. as failing to comply with the enablement requirement. The claims contain subject matter that was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
MPEP 2164.01(a) reads: In order to determine compliance with the enablement requirement of 35 U.S.C. 112(a), the Federal Circuit developed a framework of factors in In re Wands, 858 F.2d 731, 737, 8 USPQ2d 1400, 1404 (Fed. Cir. 1988), referred to as the Wands factors to assess whether any necessary experimentation required by the specification is "reasonable" or is "undue." Consistent with Amgen Inc. et al. v. Sanofi et al., 598 U.S. 594, 2023 USPQ2d 602 (2023), the Wands factors continue to provide a framework for assessing enablement in a utility application or patent, regardless of technology area. See Guidelines for Assessing Enablement in Utility Applications and Patents in View of the Supreme Court Decision in Amgen Inc. et al. v. Sanofi et al., 89 FR 1563 (January 10, 2024). These factors include, but are not limited to:
(A) The breadth of the claims;
(B) The nature of the invention;
(C) The state of the prior art;
(D) The level of one of ordinary skill;
(E) The level of predictability in the art;
(F) The amount of direction provided by the inventor;
(G) The existence of working examples; and
(H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure.
Regarding (A), Claims 1-8 are directed to a process for producing a synthesis gas steam reforming of a hydrocarbon and Claims 9-16 are directed to a plant (apparatus) for performing the same method. Said process requires 9 steps (a-i) to be performed however most of these steps are known to the art (see potentially allowable subject matter below). The exception is step a4 which requires a first and second catalyst zone, each with a catalyst for performing a particular reaction (first zone performs selective reduction of nitrogen oxides with ammonia to nitrogen, second zone performs oxidation of ammonia to nitrogen oxides).
Regarding (B), From the Specification, Page 1, Lines 11-22 “The present disclosure relates generally to synthesis gas production; more specifically, the present disclosure relates to a process and a plant for producing a synthesis gas comprising hydrogen and carbon oxides by steam reforming of a hydrocarbon containing feed stream in a steam reformer with an arrangement to minimize the emission of nitrogen oxides and ammonia. There is an ongoing desire to reduce atmospheric emissions from chemical plants, and particularly ammonia emissions from synthesis gas production plants. With the stricter regulations in place in Europe regarding ammonia emissions and atmospheric concentrations, reducing such ammonia emissions has become critical for both new plants and existing plants undergoing revamps.”. The invention is therefore understood as a modification to a conventional steam hydrocarbon (methane) reformer which further reduces ammonia emissions through the dual catalyst treatment of exhaust.
Regarding (C), the prior art recognizes multiple catalysts capable of performing the function of either selective catalytic reduction of nitrogen oxides with ammonia to nitrogen or catalytic oxidation of ammonia to nitrogen oxides.
Regarding catalysts for selective reduction of nitrogen oxides with ammonia to nitrogen, NPL “Low-temperature selective catalytic reduction of NOx with NH3 over metal oxide and zeolite catalysts—A review” Li et al. discloses the work of many other researchers together in one review article. It is understood that the work disclosed by Li et al. must inherently be prior to Li et al. (and therefore necessarily prior to the instant application). Further details may be found by following the links/references within Li et al. however for brevity each researcher’s findings are not presented as their own NPL document.
Li et al. discloses “According to literatures, many SCR catalysts containing transitional metal (Fe, V, Cr, Cu, Co and Mn) have good low-temperature SCR activity [11–14].” [Page 148, Section 2.1]. Because this appears in the single metal oxide catalyst section of Li et al. this is understood to disclose 6 separate and distinct catalysts for good low-temperature SCR activity.
Li et al. further discloses “Several kinds of manganese oxides are known, for example, MnO2, Mn5O8, Mn2O3, Mn3O4, and MnO, which are all stable in ambient conditions. Kapteijn et al.[18] reported that MnO2 exhibited the highest low temperature activity per unit surface area and Mn2O3 with the highest N2 selectivity” [Page 149, Section 2.1], which discloses 5 more suitable catalysts.
Li et al further discloses “Qi et al. [22,23] investigated the low temperature SCR behavior of MnOx–CeO2 and found that the Mn/(Mn + Ce) molar ratio, calcination temperature and O2 concentration would affect the performance significantly.” [Page 149, Section 2.2]. Regarding multimetal oxide catalysts Li et al. further discloses multiple binary metal oxide catalysts “It was found that Fe and Zr modification increased the low temperature activity and N2 selectivity, Pr could enhance the N2 selectivity and resistance to H2O and SO2 [22].” [Page 149, Section 2.2]. Regarding multimetal oxide catalysts Li et al. further discloses a trinary metal oxide catalyst “It was reported [25] with an increase in calcination temperature of iron titanate catalyst, particle size increased quickly along with the BET surface area decreasing rapidly. Liu et al. [26,27] investigated the manganese substituted iron titanate catalysts, which were prepared by co-precipitation method. The addition of Mn led to increasing of surface area and porosity, distortion and appropriate disorder of structure, enhancement of lattice oxygen mobility and NOx adsorption capacity.” [Page 149, Section 2.2].
Li et al. additionally discloses zeolite catalysts “Many ion exchanged zeolites were reported to be active in NH3-SCR reaction, such as Fe [8,52], Cu [53,54], Mn [55], and Ce [56,57]. Among such a wide family of catalysts, iron and copper zeolites seem to be particularly interesting and have been extensively studied.” [Page 151, Section 2.4].
In summary Li et al. discloses at least 21 different catalysts which can be used for catalytic selective reduction of NOx with ammonia, without identifying a clearly superior catalyst.
Regarding catalytic oxidation of ammonia to nitrogen oxides, NPL “Catalytic Oxidation of Ammonia” Chenko et al. discloses the work of many other researchers together in one review article. It is understood that the work disclosed by Chenko et al. must inherently be prior to Chenko et al. (and therefore necessarily prior to the instant application). Further details may be found by following the links/references within Chenko et al. however for brevity each researcher’s findings are not presented as their own NPL document.
Chenko et al. discloses “In the presence of platinum or cobalt oxide catalysts at 750-900°C, the main product is nitric oxide. The oxidation of ammonia in the presence of platinum catalysts (they usually consist of platinum-rhodium or platinum-rhodium-palladium alloy gauze) constitutes the basis of the modern industrial manufacture of nitric acid1. In the presence of manganese oxide catalysts at lower temperatures (300-400°C), nitrous oxide is formed in fairly high yields2; this product is a valuable anaesthetic used in medicine. In the presence of vanadium pentoxide at 500-600°C, ammonia is oxidized only to molecular nitrogen” [Page 1119, Section 1], which discloses 4 catalysts.
Chenko et al. further discloses 9 (8 additional) metal catalysts in Table 1 [Page 1119] for oxidation of ammonia and 17 (14 additional) metal oxide catalysts in Table 2 [Page 1127].
Therefore Chenko et al. discloses 26 catalysts for the oxidation of ammonia to nitrogen oxides without identifying a clearly superior catalyst.
Regarding (D), the person having ordinary skill in the art is capable of synthesizing these catalysts through conventional synthetic routes known in the art. A person having ordinary skill in the art would additionally be able to test known catalysts and measure their efficiency by measuring the gas output from the process by known means (such as a mass spectrum).
Regarding (E), the function of a single catalyst is not considered an unpredictable art. Although some variation in catalytic efficacy is expected between batches of catalyst generally speaking it is understood that the same catalyst will perform consistently within the same margin of error as long as care is taken to prevent fouling (by mechanisms such as coke deposition) and/or steps taken to regenerate a catalyst after a certain operating time.
However, the art does not recognize the dual function of both catalysts when used together. As an example when a particular ammonia oxidation catalyst is being tested the ammonia concentration is typically set to a constant value, however in the dual catalyst mode of operation the amount of ammonia received (as well as other operating conditions such as temperature) is determined by the efficiency of the upstream selective catalytic reduction catalyst. There exists no indication within the art that any particular ammonia oxidation catalyst will work the same when deployed downstream of another catalyst which effects process conditions (concentrations, temperatures, etc.).
Regarding (F), there is no direction provided by the inventor, other than to generally state the goal of the catalyst (which reaction it is capable of performing). The specification states “the catalyst to be used in the first catalyst zone is active for the selective catalytic reduction (SCR) of nitrogen oxides with ammonia to nitrogen, and the catalyst to be used in the second catalyst zone is active for catalytic oxidation of ammonia to nitrogen oxides”, which amounts to describing what the catalyst does but falls short of describing what the catalyst is. MPEP 2114.II clarifies that “"[A]pparatus claims cover what a device is, not what a device does." Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469 (Fed. Cir. 1990) (emphasis in original). A claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim.”. In other words the inventors disclose no structure, only an intended function of the catalysts.
The specification provides no guidance to the identity of the catalyst (single metal oxide, multimetal oxide, non-oxide metals) or to which particular outcomes are the most important (selectivity, reactivity, temperature windows for operation, etc.) to select a catalyst for.
Regarding (G), no working examples are disclosed.
Regarding (H), from just the two review articles currently being considered there are 21 different known catalysts that could go in the first zone and 26 catalysts that could go in the second zone. This leads to 546 different combinations of catalysts that would need to be synthesized and tested (ideally under multiple different conditions to simulate operational variations) at a minimum. This is almost certainly an undercount of the necessary experimentation to determine the optimal conditions because multimetal catalysts disclosed by Li et al. are only counted once when different ratios of metals almost certainly are disclosed. This alone is sufficient to change the possible combinations from finite and large to infinite (or at least highly unwieldly) as a disclosure of two different ratios of metals that are effective renders intervening ratios obvious to try. Additionally the above analysis of the prior art should not be considered an exhaustive search of every catalyst possible.
In summary, the claims are directed to a method of reducing emissions by using two catalysts together. The art recognizes many catalysts that are capable of performing the required reactions by themselves but is silent towards combinations of these catalysts (as claimed). The inventors provide no direction to a person having ordinary skill in the art to suggest which catalyst among the many known would function well in use with another catalyst and provide no working examples of catalysts used together to enhance the reduction of ammonia emissions. One of ordinary skill in the art would need to test at least 500 and potentially an infinite number of combinations of known catalysts together in order to discover for themselves the most efficient mode of operation. The claims are thus rejected under 35 U.S.C. 112(a)/1st par. for failing to satisfy the enablement requirement thereof.
Potentially Allowable Subject Matter
Claims 1-16 would be allowable if rewritten or amended to overcome the 35 U.S.C. 112(a)/1st par. rejections above. The closest prior art is given by US 2009152501 Furchtbar et al. Claim 9 requires “A plant for producing a synthesis gas comprising hydrogen and carbon oxides by steam reforming of a hydrocarbon containing feed stream with steam in a steam reformer”. Furchtbar et al. discloses “In steam-reforming processes, feedstocks that contain hydrocarbons, such as natural gas, light gasoline, or naphtha, are mixed with water vapor and reacted in steam reformers to form synthesis gas—a gas mixture that contains carbon monoxide (CO) and hydrogen (H2). … The object of the invention is therefore to indicate a process of the above-mentioned type as well as a device for implementing the process” [0002-0006].
Claim 9 further requires “the plant comprising the following means and apparatuses, arranged in fluid connection with one another: (a) a steam reformer, comprising: (a1) a plurality of catalyst filled reformer tubes with means for introducing the hydrocarbon containing feed stream and steam into the reformer tubes, and means for discharging a crude synthesis gas stream from the reformer tubes”. Furchtbar et al. discloses “The preheated natural gas/water vapor mixture is conveyed via line 2 to the distributor V and distributed in the reactor pipes R that are filled with a suitable catalyst material, in which it is reacted in an endothermic reaction in a synthesis gas that contains hydrogen and carbon monoxide. The synthesis gas is collected in the collector Z and sent via line 3 to the cooler E2.”.
Claim 9 further requires “(a2) a reformer furnace with a floor, a ceiling and side walls which form a furnace interior, with the reformer tubes being arranged inside of the furnace interior and being heated by a plurality of burners”. Furchtbar et al. discloses “a steam reformer that is heated from the outside with burners.” [0024], although Furchtbar et al. does explicitly disclose that the reformer has a floor, a ceiling and side walls which form a furnace interior this is understood to be implicitly disclosed as it is conventional for furnaces to retain their hot gasses for efficiency.
Claim 9 further requires “(a3) a flue gas duct being arranged in fluid connection to the furnace interior through one of the side walls”. Furchtbar et al. discloses “the steam reformer is connected to a flue gas system” [0016] and the side connection can be seen clearly in Figure 1.
Claim 9 further requires “(a4) a catalyst unit being arranged inside of the flue gas duct and outside of the furnace interior, the catalyst unit comprising a first catalytic zone active for the selective catalytic reduction of nitrogen oxides with ammonia to nitrogen, and a second catalytic zone active for catalytic oxidation of ammonia to nitrogen oxides”. Furchtbar et al. discloses neither a first nor a second catalyst within the flue gas duct. They disclose that the reaction proceeds without the use of a catalyst “If the hot flue gas also contains nitric oxides, ammonia can be degraded via another reaction. This reaction is known as a selective, non-catalytic reduction (abbreviated SNCR, for Selective Non Catalytic Reduction) and forms the basis for the industrial removal of nitrogen from flue gases.” [0011].
Claim 9 further requires “(b) means for providing the hydrocarbon containing feed stream and a reforming steam stream and means for introducing the hydrocarbon containing feed stream and the reforming steam stream into the reformer tubes, (c) means for providing a fuel gas stream and an oxygen containing oxidant stream and introducing the fuel gas stream and the oxygen containing oxidant stream into the burners; (d) means for discharging a crude synthesis gas comprising hydrogen, carbon oxides, unconverted steam, and ammonia from the reformer tubes; (e) means for discharging a flue gas stream from the furnace interior through the flue gas duct, and means for routing at least a portion of the flue gas stream through the catalyst unit”. Furchtbar et al. does not explicitly disclose each of these means, however they are considered implicitly disclosed because their invention would not function as described without them, with the exception of the means for routing at least a portion of the flue gas stream through the catalyst unit. As Furchtbar et al. does not disclose a catalyst unit they would not implicitly disclose routing flue gasses through said unit.
Claim 9 further requires “(f) at least one cooling apparatus for cooling the crude synthesis gas stream to a temperature below its dew point to form an aqueous condensate stream comprising ammonia, a phase separation apparatus for separating and discharging a synthesis gas stream depleted in water and ammonia from the aqueous condensate stream comprising ammonia; (g) a stripping apparatus for stripping the aqueous condensate stream comprising ammonia with a stripping gas stream, means for routing out a condensate stream depleted in ammonia from the stripping apparatus, means for routing out a stripping gas stream enriched in ammonia from the stripping apparatus; (h) means for introducing at least a portion of the stripping gas stream enriched in ammonia into the flue gas duct at a first injection point provided on the flue gas duct upstream of the catalyst unit”. Furchtbar et al. discloses “According to the prior art, such synthesis gas units comprise a device (degasser) for degassing process condensate, in which the ammonia-containing exhaust gas can be produced as well as a flue gas system for discharging the hot, oxygen containing flue gas that accumulates in the heating of the steam reformer into the atmosphere. An especially preferred variant of the device according to the invention therefore calls for the degasser being connected to the flue gas system via a line system in such synthesis gas units, via which line system the ammonia-containing exhaust gas from the degasser can be introduced into the flue gas system at a suitable location” [0022]. Because condensation is disclosed a cooling apparatus must inherently be present. Additionally since the condensate stream (liquid) and flue gas stream (gas) are separated a phase separation apparatus must inherently be present. Although Furchtbar et al explicitly discloses injecting ammonia gas at a first injection point it is noted that this point cannot be upstream of the catalyst unit because no catalyst unit is disclosed.
Claim 9 further requires “(i) wherein means are comprised that allow that both the at least a portion of the flue gas stream and the at least a portion of the stripping gas stream enriched in ammonia pass through the first catalyst zone and subsequently through the second catalyst zone of the catalyst unit.”. Furchtbar et al. does not disclose a first or second catalyst unit.
Claims 1-8 are directed to a similar method performed on an apparatus having the limitations of Claim 9. Therefore Furchtbar et al. fails to teach the corresponding method steps regarding the catalyst units (see above).
Conclusion
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/JOSHUA MAXWELL SPEER/
Examiner
Art Unit 1736
/DANIEL BERNS/Primary Examiner, Art Unit 1736
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