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
Claims 27-28 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 06/23/2026.
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) 15-26 is/are rejected under 35 U.S.C. 103 as being unpatentable over WO2021060985A1, hereinafter ‘Mulder’, in view of US20200172394A1, hereinafter ‘Han’.
Regarding Claim 15, Mulder discloses a process for a synthesis of ammonia (Page 1, lines 5-6), the process comprising:
a) reacting an ammonia make-up gas, containing hydrogen and nitrogen, in an ammonia converter at an ammonia synthesis pressure, thereby obtaining an ammonia-containing effluent (Page 3, lines 15-17, 20-21: The method may comprise reacting dihydrogen and dinitrogen to form the ammonia in a (system comprising a) reactor. The method may further comprise providing a reactor gas mixture from the reactor to a recycle loop. The method may further comprise providing at least part of the reactor gas mixture from the recycle loop to the reactor, i.e., reacting an ammonia make-up gas. This process is inherently performed at an ammonia synthesis pressure);
b) subjecting said ammonia-containing effluent to a cooling and separation step, thereby obtaining liquid ammonia and a side stream containing hydrogen and impurities (Page 3, lines 33-35: the reactor may generate NH3, and may separate NH3 from unreacted H2, N2 using a separator, such as a cooling trap, wherein NH3 may be removed from the system and the unreacted H2 and N2 may be recycled into the reactor);
c) subjecting at least a portion of said side stream to a hydrogen recovery process, thereby obtaining recovered hydrogen (Page 26, line 26 – Page 27, line 4: In embodiments there will be a purge gas stream to purge inerts from the separator gas mixture, i.e. the system may comprise a purge unit configured to purge inerts from the recycle gas flow…The hydrogen released via the purge stream may be recovered using a hydrogen recovery system and be added to the hydrogen inlet stream, i.e., the purge unit may comprise a hydrogen recovery system configured to recover dihydrogen from the purge gas flow and to provide the dihydrogen to the supply);
e) producing a second portion of the hydrogen contained in the ammonia make-up gas separately from said reforming process using a renewable energy source (Page 13, lines 6-8: In embodiments, the method may comprise generating dihydrogen using an electrolyser, especially an integrated battery and electrolyser also indicated as a battolyser, in dependence of availability of (renewable) energy sources);
f) sending at least a portion of said recovered hydrogen obtained at step c) to a hydrogen storage (Page 26, line 35 – Page 27, line 4: The hydrogen released via the purge stream may be recovered using a hydrogen recovery system and be added to the hydrogen inlet stream, i.e., the purge unit may comprise a hydrogen recovery system configured to recover dihydrogen from the purge gas flow and to provide the dihydrogen to the supply, especially to the intermediate dihydrogen storage); and
g) fully or partly replacing said second portion of hydrogen of step e) when said renewable energy source is fully or partly unavailable with hydrogen from said storage (Page 31, lines 4-8: the method comprises generating dihydrogen using an electrolyser in dependence of availability of renewable energy, especially from the renewable energy source. In the depicted embodiment, the electrolyser provides the generated dihydrogen to an intermediate dihydrogen storage 112 configured to (temporarily) store dihydrogen; Page 25, lines 21-24: If little H2 production is available (i.e., available from generation by renewable energy), the intermediate dihydrogen storage may first be filled and the reactor may then be filled (batchwise or continuously) from the intermediate storage).
Further regarding Claim 15, Mulder discloses the use of renewable energy for the production of hydrogen, and that such production is dependent on availability of such energy sources. Further, Mulder discloses that the system, especially the supply, may comprise an intermediate hydrogen storage. The intermediate hydrogen storage may further be functionally coupled to the supply, such that the supply can provide dihydrogen from the intermediate hydrogen storage to the reactor. The intermediate dihydrogen storage may especially be configured for the storage of an amount of dihydrogen sufficient to operate the reactor at full capacity for at least one hour (Page 22, line 34 – Page 23, line 5).
However, Mulder does not disclose producing a first portion of the hydrogen contained in the ammonia make-up gas by reforming a hydrocarbon source in a reforming process, or fully or partly replacing said second portion of hydrogen of step e) when said renewable energy source is fully or partly unavailable with hydrogen from said storage.
Han discloses the preparation of ammonia synthesis gas combining electrolysis of water and autothermal reforming of a gaseous hydrocarbon feed stock in the preparation of a hydrogen and nitrogen containing ammonia synthesis gas ([0001]). A person of ordinary skill in the art would have recognized Han as analogous the claimed invention, as both references are drawn to the same field of endeavor, the synthesis of ammonia - 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.
Han discloses a problem with the combination of electrolysis and air separation is that oxygen is produced as by-product in both electrolysis and air separation, which has no use in the ammonia synthesis, and can be considered as energy losses ([0008]). To solve this problem, Han teaches a combination of an autothermal reforming process using oxygen from the electrolysis of water in the partial oxidation of hydrocarbon feed stock in the ATR process. Hydrogen from the electrolysis can be used to adjust the hydrogen/nitrogen molar ratio in the ammonia synthesis gas approximately to the stoichiometric ratio required for the production of ammonia, as well as additional synthesis gas production ([0009]). Han discloses that one of the major advantages of the combination of reforming and electrolysis for producing hydrogen is a considerably increased efficiency of the electrolysis unit by nearly 30%, compared to the efficiency in the prior art processes employing solely electrolysis and air separation, without ATR or secondary reforming ([0030]).
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 combination of autothermal hydrocarbon reforming and electrolysis for the production of hydrogen as taught by Han in the process according to Mulder. Such a combination has been shown to increase the efficiency of hydrogen production by electrolysis, and would therefore be expected to improve the efficiency of the ammonia synthesis process of Mulder.
Regarding Claim 16, Mulder as modified above makes obvious the electrolysis of water, as discussed above.
Regarding Claim 17, Mulder as modified above makes obvious the electrolysis of water is powered by solar energy (Mulder, Page 29, lines 11-12: the renewable energy source 40 may also comprise, for example, a solar panel).
Regarding Claim 18, Mulder as modified above makes obvious hydrogen storage is performed at a pressure of at least 50 bar (Mulder, Page 17, lines 27-29: in the supply, the provided dinitrogen and dihydrogen may especially be pressurized, such as pressurized at at least 100 bar, such as at least 200 bar, especially at least 250 bar – given that the intermediate hydrogen storage is disclosed as functionally coupled to the supply, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to store hydrogen at at least 100 bar, 200 bar, or 250 bar, such that the stored hydrogen may be supplied to the reactor at the designated pressure).
Regarding Claim 19, Mulder as modified above makes obvious said recovered hydrogen obtained at step c) has a pressure of at least 50 bar (as discussed above, the hydrogen in the supply is pressurized to at least 100 bar, such as at least 200 bar, especially at least 250 bar. Further, Mulder discloses recovering dihydrogen from the purge gas flow and providing the dihydrogen to the supply, especially to a compressor feed in the supply (Page 31, lines 27-31) – given this, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to pressurize the recovered hydrogen to a pressure of at least 100 bar, 200 bar, or 250 bar such that the stored hydrogen may be supplied to the reactor at the designated pressure).
Regarding Claim 20, Mulder as modified above makes obvious said recovered hydrogen obtained at step c) is sent to hydrogen storage without compression when the pressure of recovery of said hydrogen is sufficient for storage, or is compressed when the storage pressure is higher than the recovery pressure (Mulder, Page 31, line 35 – Page 32, line 4: For ease of operation, it may be preferable to provide the recovered dihydrogen to the intermediate dihydrogen storage as the gas pressure of the recovered dihydrogen gas flow may differ from the gas pressure of the intermediate dihydrogen storage, which would have to be accounted for when providing the recovered dihydrogen directly to the compressor feed).
Regarding Claim 21, Mulder as modified above makes obvious said second portion of hydrogen, which is produced with renewable energy, accounts for up to 50% of the hydrogen in the ammonia make-up gas ([0031]: The efficiency of water electrolysis is defined as the Lower Heating Value (LHV) of hydrogen produced divided by the electrical power consumed; Table 1, [0034]: when utilizing 205.7 MW power for water electrolysis with an efficiency of 60%, the saving of natural gas is 129 MW (LHV=39771 KJ/Nm3). Assuming a hydrogen (LHV) of approximately 33.3 kWhr/kg (U.S. Department of Energy), 205.7 MW of power at 60% efficiency is 123.42 MW, or 123,420 kW, and the approximate yield of hydrogen is 123,420 kWhr/hr / 33.3 kWh/kg = 3,706 kg H2/hr of hydrogen generated by electrolysis, or 3.706 metric tons per hour. Further, for a 2200 MTPD (metric tons per day) ammonia plant ([0033]), the required amount of hydrogen, derived from the stoichiometry of the reaction, is 390.6 metric tons of hydrogen per day, or 16.27 metric tons per hour. Therefore, the percent of hydrogen derived from electrolysis is 3.706 / 16.27 = 22.8 %, which falls within the claimed range. Accordingly, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to utilize such an amount of hydrogen derived by electrolysis in the process of Mulder as modified above, as this amount has been disclosed as achieving an almost 30% increase in efficiency ([0034]).
Regarding Claim 22, Mulder as modified above makes obvious said second portion of hydrogen is produced at the same or substantially the same pressure as a purified make-up gas obtained from reforming and purification (Han, [0021]: When using the hydrogen stream from the water electrolysis for adjustment of the ammonia synthesis gas, the water electrolysis is preferably performed at increased pressure corresponding to the pressure of the process gas, which saves compression energy).
Regarding Claim 23, Mulder as modified above makes obvious said ammonia converter is part of an ammonia synthesis loop and the hydrogen separately produced from renewable energy or taken from the hydrogen storage is introduced into said loop (as discussed above, hydrogen generated from electrolysis and stored in intermediate hydrogen storage is introduced into the ammonia synthesis reactor).
Regarding Claims 24 and 25, Mulder as modified above makes obvious the reforming step d) includes: reforming a hydrocarbon source and purification of the so obtained reformed gas; obtaining a purified reformed gas; feeding the purified reformed gas, with the addition of nitrogen, to said ammonia converter via a main syngas compressor; and feeding the hydrogen separately produced from renewable energy to the ammonia converter via said main syngas compressor, and that the hydrogen separately produced from renewable energy is fed to the suction side of said main syngas compressor together with the purified reformed gas (Han, [0011]-[0019], [0022], [0037]-[0042]: the process of utilizing both electrolysis and reforming in Han comprises reforming a hydrocarbon and treating the process gas stream withdrawn from the autothermal reforming step (d) in one or more water gas shift reactions, removing the carbon dioxide from the water gas shift treated process gas stream, and purifying said process gas stream; the required mole ratio of hydrogen to nitrogen is adjusted by the addition of process air introduced in the reforming step; the hydrogen stream produced by electrolysis will then be introduced into the purified process gas preferably near the suction of a synthesis gas compressor for the ammonia loop).
Regarding Claim 26, Mulder as modified above makes obvious a first portion of said side stream separated from the converter effluent is sent to hydrogen recovery and second portion of said side stream is reintroduced into the ammonia converter (Mulder, Page 26, lines 33-35: during operation, 1-10% of the recycle gas flow may be directed to the purge unit, thereby continuously removing (approximately) 1-10% of the inerts from the recycle gas flow; Page 27, lines 33-34: The recycle loop may provide at least part of the reactor gas mixture from the recycle loop (back) to the reactor, especially via the compressor).
Conclusion
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LOGAN LACLAIR
Examiner
Art Unit 1736
/L.E.L./ Examiner, Art Unit 1736
/ANTHONY J ZIMMER/ Supervisory Patent Examiner, Art Unit 1736
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