Production of renewable nitrogenous products

Abstract

Provided herein are systems and methods for producing renewable nitrogenous products.

Description

[0001] PRODUCTION OF RENEWABLE NITROGENOUS PRODUCTS

[0002] BACKGROUND

[0003] Nitrogenous chemical products have many potential uses, but a primary use includes agricultural fertilizers (about 88% of all NH3 production in 2018). Nitrogen fertilizers are typically made from ammonia (NH3) produced by the Haber-Bosch process. In this energy- intensive process, natural gas (CH4) usually supplies the hydrogen (H2), and the nitrogen (N2) is derived from the air. The ammonia generated by the reaction of H2 and N2 is separated from the reaction effluent via mechanical refrigeration and condensation, which produces anhydrous liquid ammonia typically stored at ambient pressure and cold (e.g., -33C) temperature in suitably designed cryogenic tanks.

[0004] Anhydrous ammonia is used as a feedstock for all downstream conversion processes, including the production of other nitrogen fertilizers, such as ammonium nitrate (NH4NO3) and urea (CO(NH2)2).

[0005] The admixture of ammonium nitrate and urea is stable and known as UAN. In UAN, the combined solubility of ammonium nitrate and urea is much higher than that of either component alone, having a total nitrogen content (e.g., about 32%) approaching that of solid ammonium nitrate (33.5%). Given the ongoing safety and security concerns surrounding fertilizer-grade solid ammonium nitrate, UAN provides a considerably safer alternative without entirely sacrificing the agronomic properties that make ammonium nitrate an attractive fertilizer. It is also more convenient to store and handle than a solid product and easier to apply accurately to the land by mechanical means.

[0006] SUMMARY

[0007] By some measures, production of ammonia and its derivatives accounts for approximately 3-5% of global greenhouse gas (GHG) emissions. Therefore, there is a critical need for sustainable production of nitrogenous compounds (i.e., with reduced or negligible GHG emissions). Such systems and methods are provided herein, which use renewable inputs such as water, air, CO2, and renewable power. In some cases, systems and methods provided herein can be used for the production of nitrogenous products starting from H2 (regardless of how such H2 is generated), CO2, air and water.

[0008] In some instances, the H2 is provided from geologic sources (e.g., accessed via one or more wells drilled into the earth for the purposes of deriving hydrogen, or as a byproduct of other geologic extraction). In other instances, renewable power can be used to electrolyze water into H2 and O2, where the H2 is a reactant in NH3 production. H2 is reacted with N2 separated from air to generate NH3 via an equilibrium reaction. Such NH3 can be separated from the unreacted H2 and N2 via absorption with water to form an aqueous ammonia solution. This aqueous solution can be sold as a product (e.g., 20% aqua-ammonia) or fed to a downstream ammonia conversion process. Alternatively, water can be distilled from such solution to generate commercial anhydrous ammonia (>99.5%wt NH3) or an aqueous ammonia solution with a higher NH3 concentration, which can be sold as a high concentration nitrogenous product or fed to a downstream process for further conversion of NH3 into other nitrogenous products such nitric acid, ammonium nitrate, other nitrates, urea, UAN or any combination of such products. The heat necessary for the distillation of the aqueous ammonia solution can be derived from ammonia synthesis, from any of the downstream ammonia conversion processes (for example, from the exothermic oxidation of NH3 to nitrates), from any external source of energy (including renewable power), or any combination of all the previous sources.

[0009] The O2 from electrolysis can be used to oxidize the NH3 into other nitrogenous compounds such as nitric acid and ammonium nitrate.

[0010] Urea can be produced by the reaction of NH3 with CO2 in a series of two equilibrium reactions. The first equilibrium is a fast, exothermic, conversion of (liquid) ammonia with CO2 at high temperature and pressure to form carbamate (H2N-COONH4). The second equilibrium is the slower and endothermic decomposition of ammonium carbamate into urea and water. A large reaction vessel can be used to allow the slow urea formation reaction time to reach equilibrium and, because the urea conversion is incomplete, the product can be separated from unchanged ammonium carbamate, product water and unreacted NH3 and CO2.

[0011] UAN is typically produced by blending purity urea and ammonium nitrate with water. However, counter-intuitively, the inventors of the present disclosure recognized that it can be counter-productive to make purity urea and ammonium nitrate, if the desired end product is UAN because much of the water required for UAN can be derived from an urea intermediate (urea liquor, a -75-80% aqueous solution of urea) and a concentrated ammonium nitrate aqueous solution, which is the typical intermediate in solid ammonium nitrate production. Therefore, systems and methods are provided herein for efficiently and synergistically making UAN directly in a renewable process with air, water, CO2 and renewable power inputs. Overall, the systems and methods described herein can replace unsustainable, fossil-fuel- based ammonia, urea, nitric acid, ammonium nitrate, and / or UAN production plants with renewable counterparts.

[0012] Accordingly, in one embodiment is provided a method for making ammonia, the method comprising: a. mixing (H2) with nitrogen (N2) to create a mixed stream and optionally treating the mixed stream in a de-oxidation reactor to remove remaining oxygen (O2); b. de-hydrating a combination of the mixed stream and a recycle stream to create a dry stream; c. reacting the H2 and N2 contained in the dry stream in a synthesis reactor to form an effluent stream containing ammonia (NH3); d. absorbing NH3 from the effluent stream in water to generate an aqua-ammonia solution and a the recycle stream, which recycle stream contains unreacted H2 and N2 and is combined with the mixed stream; e. separating a fraction of the recycle stream to create a purge stream to control accumulation of inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product; and g. using the heat generated by the ammonia synthesis reactor to power the dehydration and / or the distillation.

[0013] In certain of the foregoing embodiments, the hydrogen (H2) is provided from a geologic source. In some other different embodiments, the hydrogen (H2) is provided from an electrolyzer that is powered using renewable power, for example by electrolyzing water to produce hydrogen and oxygen. In some further embodiments, the electrolyzer further produces oxygen (O2) and the method further comprises mixing H2 with N2 and treating such mixed stream in a deoxidation reactor to remove remaining O2.

[0014] In any of the foregoing embodiments, a production rate of ammonia is increased or decreased in response to a price or availability of renewable power.

[0015] In different exemplary embodiments, the N2 is produced by cryogenic air liquefaction and distillation, while in different embodiments the N2 is produced by Pressure Swing Adsorption (PSA), or in other embodiments the N2 is produced in a selectively permeable membrane.

[0016] In other of any of the foregoing embodiments, the de-hydration is performed with Temperature Swing Adsorption (TSA), or in different embodiments the de-hydration is performed by contacting the wet gas mixture with a molecular sieve material, and in other different embodiments the de-hydration is performed by contacting the wet gas mixture with an aqueous solution of ammonia or with liquid ammonia.

[0017] In yet other of any of the foregoing embodiments, the NH3 is synthesized in a reactor at a pressure below about 80 bar, below about 60 bar, about 40 bar or below about 40 bar. In different embodiments, the NH3 is synthesized in the presence of a catalyst, which catalyst is in direct contact with a pressure vessel or the NH3 is synthesized in the presence of a catalyst, which catalyst is contained in tubes inside a vessel.

[0018] In still more different embodiments of the foregoing, a portion of the NH3 contained in the effluent stream is condensed and separated and the remaining portion is absorbed in water and / or the NH3 in the effluent stream is absorbed in water using a column filled with packing and / or the NH3 in the effluent stream is absorbed in water using a column equipped with trays.

[0019] In other different embodiments, the aqua-ammonia solution is distilled using a column filled with packing and / or the aqua-ammonia solution is distilled using a column equipped with trays. In other related embodiments, the distillation of the aqua-ammonia solution is at least partially powered by an external source of heat.

[0020] In more different embodiments of the foregoing, formation of the NH3 produces heat, which heat is captured in a hot oil, hot water, or steam system.

[0021] In other embodiments, the H2 contained in the purge stream is separated and recycled to ammonia synthesis and / or the H2 contained in the purge stream is separated, further compressed, and recycled to ammonia synthesis.

[0022] In still different embodiments of any of the foregoing methods, the method further comprises: a. separating the purge stream into a concentrated H2 stream and a tail gas stream that contains non-reactive species (e.g., N2, CH4 if present in the system, and noble gases Ar and He); b. recycling the purge stream to the ammonia synthesis; c. concentrating Ar and / or He from the teal gas stream to create a product stream.

[0023] Another embodiment provides a method for making ammonia, the method comprising: a. mixing H2 with N2 to create a mixed stream; b. de-hydrating the mixed stream stream and a recycle stream to create a dry stream; c. reacting the H2 and N2 contained in the dry stream in a synthesis reactor to form an effluent stream containing ammonia (NH3); d. absorbing NH3 from the effluent stream in water to generate an aqua-ammonia solution and a recycle stream that contains the unreacted H2 and N2; e. separating a fraction of the recycle stream to create a purge stream to control the accumulation of any inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product; g. using heat generated by the ammonia synthesis reactor to power the de-hydration and / or the distillation; h. separating the purge stream into a concentrated H2 stream and a tail gas stream that contains all non-reactive species (N2, CH4 if present in the system, and noble gases Ar and He); i. recycling the purge stream to the ammonia synthesis; j . concentrating Ar and / or He from the tail gas stream to create a product stream.

[0024] In certain of the above embodiments, H2 is separated from the purge stream via cryogenic distillation or in other embodiments H2 is separated from the purge stream via Pressure Swing Adsorption (PSA) or in different embodiments H2 is separated from the purge stream in a selectively permeable membrane.

[0025] In some other different embodiments, Ar and / or He are separated from the tail gas stream via cryogenic distillation or Ar and / or He are separated from the tail gas stream via Pressure Swing Adsorption (PSA) or Ar and / or He are separated from the tail gas stream in a selectively permeable membrane, for example in some embodiments the tail gas stream is recycled to ammonia synthesis after removal of Ar and / or He.

[0026] In certain other embodiments, the method further comprises: a. feeding the purge stream to a power generation unit where the H2 in stream is reacted with O2 to create an exhaust stream; b. concentrating Ar and / or He from the exhaust stream to create a product stream and a tail gas stream.

[0027] Another different embodiment provides a method for making ammonia, the method comprising: a. mixing H2 with N2 to create a mixed stream; b. de-hydrating the combination of the mixed stream and recycle stream to create a dry stream; c. reacting the H2 and N2 contained in the dry stream in a synthesis reactor to form ammonia (NH3) contained in the effluent stream; d. absorbing NH3 from the effluent stream in water to generate an aqua-ammonia solution and a recycle stream that contains the unreacted H2 and N2; e. separating a fraction of the recycle stream to create a purge stream to control the accumulation of any inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product; g. using the heat generated by the ammonia synthesis reactor to power the dehydration and / or the distillation; h. feeding the purge stream to a power generation unit where the H2 is reacted with O2 to create an exhaust stream; i. concentrating Ar and / or He from the exhaust stream to create a product stream and a tail gas stream.

[0028] In certain of the above embodiments, the power is generated in a fuel cell, or power is generated in an internal combustion engine, or power is generated in a gas turbine, or power is generated in linear generator or the power is utilized within the process.

[0029] In other different embodiments of the foregoing, heatt is recovered from the exhaust stream, for example in some embodiments, the heat is captured in a hot oil, hot water, or steam system, and in other embodiments the recovered heat is utilized within the process.

[0030] In other different embodiments of the method, water is separated from the exhaust stream prior to concentrating Ar and / or He.

[0031] In still more embodiments, Ar and / or He are separated from the exhaust stream via cryogenic distillation, or Ar and / or He are separated from the exhaust stream via Pressure Swing Adsorption (PSA) or Ar and / or He are separated from the exhaust stream in a selectively permeable membrane.

[0032] In other more specific embodiments, the method further comprises: a. oxidizing any combination of the aqua-ammonia solution and the concentrated ammonia product to form a NOx stream rich in nitrogen oxides (NOx); b. absorbing NO2 from the NOx stream in water to generate an aqueous solution of nitric acid (HNO3) and a vapor stream. Still other embodiments are directed to a method for making ammonia, the method comprising: a. mixing H2 with N2 to create a mixed stream; b. de-hydrating the combination of the mixed stream and a recycle stream to create a dry stream; c. reacting the H2 and N2 contained in the dry stream in a synthesis reactor to form an effluent stream comprising ammonia (NH3); d. absorbing NH3 from the effluent stream water to generate an aqua-ammonia solution and a recycle stream that contains the unreacted H2 and N2; e. separating a fraction of the recycle stream to create a purge stream to control the accumulation of any inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product; g. using the heat generated by the ammonia synthesis reactor to power the dehydration and / or the distillation; h. oxidizing any combination of the aqua-ammonia solution and the concentrated ammonia product to form a NOx stream rich in nitrogen oxides (NOx); i. absorbing NO2 from the NOx stream in water to generate an aqueous solution of nitric acid (HNO3) and a vapor stream.

[0033] In certain of these embodiments, oxidation of the NH3 produces heat, which heat is captured in a hot oil, hot water, or steam system, for example in some embodiments the captured heat is utilized within the process.

[0034] In other different embodiments, the NH3 is oxidized with oxygen in the presence of a catalyst, for example in some embodiments the catalyst comprises a platinum group metal and optionally rhodium, and in other embodiments the catalyst comprises cobalt.

[0035] In other embodiments of the foregoing method, the method further comprises cooling the NOx stream while allowing the continuing oxidation of nitrogenous compounds to NO2, or the method further comprises using O2 derived from electrolysis to further oxidize nitrogen oxides such as nitrous oxide (N2O) and nitric oxide (NO) to nitrogen dioxide (NO2), or the method further comprises using O2 derived from electrolysis, ozonating a portion of said O2, and using the partially ozonated stream to further oxidize nitrogen oxides such as nitrous oxide (N2O) and nitric oxide (NO) to nitrogen dioxide (NO2), or the method further comprises using O2 derived from air separation to further oxidize nitrogen oxides such as nitrous oxide (N2O) and nitric oxide (NO) to nitrogen dioxide (NO2), or the method further comprises using O2 derived from air separation, ozonating a portion of said O2, and using the partially ozonated stream to further oxidize nitrogen oxides such as nitrous oxide (N2O) and nitric oxide (NO) to nitrogen dioxide (NO2).

[0036] In yet more embodiments, the aqueous solution of HNO3 is neutralized with any combinations of stream the aqua-ammonia solution and concentrated ammonia product to form an aqueous solution of ammonium nitrate (NH4NO3), for example in some embodiments neutralization of the HNO3 produces heat, which heat is captured in a hot oil, hot water, or steam system, for example the captured heat may be utilized within the process. Or, in different embodiments, neutralization of the HNO3 produces heat, which heat is utilized to evaporate water contained in the aqueous solution of HNO3.

[0037] In some more different embodiments, the vapor stream is treated to separate N2 from the other compounds, for example in some embodiments the separated N2 is recycled to ammonia synthesis.

[0038] In other embodiments, the aqueous solution of ammonium nitrate is further concentrated or diluted by removing or adding water, or the aqueous solution of ammonium nitrate is prilled or otherwise converted into solid ammonium nitrate, for example in some embodiments more concentrated or diluted aqueous solution of ammonium nitrate is prilled or otherwise converted into solid ammonium nitrate.

[0039] In other embodiments of any of the foregoing methods , the method further comprises: a. reacting any combination of the aqua-ammonia product and the concentrated ammonia product with CO2 to form an effluent stream rich in urea (CH4N2O); b. separating an aqueous solution of urea from said effluent stream.

[0040] Other different embodiments provide a method for making ammonia, the method comprising: a. mixing H2 with N2 to create a mixed stream; b. de-hydrating the combination of the mixed stream and a recycle stream to create a dry stream; c. reacting the H2 and N2 contained in the dry stream in a synthesis reactor to form an effluent stream containing ammonia (NH3); d. absorbing NH3 from the effluent stream in water to generate an aqua-ammonia solution and the recycle stream that contains the unreacted H2 and N2; e. separating a fraction of the recycle stream to create a purge stream to control the accumulation of any inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product; g. using the heat generated by the ammonia synthesis reaction to power the dehydration and / or the distillation; h. reacting any combination of the aqua-ammonia solution and the concentrated ammonia product with CO2 to form an effluent stream rich in urea (CH4N2O); i. separating an aqueous solution of urea from said effluent stream.

[0041] For example, in some embodiments the CO2 is derived from flue gas, or the CO2 is derived from fermentation of biomass or waste products, or the CO2 is derived from fermentation of biomass (for example, corn) for the production of ethanol, or the CO2 is derived from industrial facilities (for example, natural gas processing), or the CO2 is sourced from a pipeline, or the CO2 is sourced from Direct Air Capture (DAC).

[0042] In other different embodiments, the CO2 has a purity of less than 99% and more than 80%. In more embodiments, the urea synthesis is conducted at a pressure above 150 bar, while in different embodiments the molar ratio of NH3 and CO2 in the feed streams to the urea synthesis is more than about 2.

[0043] In further embodiments, the aqueous solution of urea is further concentrated in urea by removing water, for example in some embodiments the concentrated solution of urea is prilled or granulated or otherwise converted into solid urea.

[0044] In other different embodiments, the aqueous solution of urea is further diluted in urea by removing water to form Diesel Exhaust Fluid (DEF).

[0045] Other embodiments of any of the foregoing methods comprise: a. oxidizing a portion of the aqua-ammonia solution and the concentrated ammonia to form a NOx stream rich in nitrogen oxides (NOx); b. absorbing NO2 from the NOx stream in water to generate an aqueous solution of nitric acid (HNO3) and a vapor stream; c. reacting the remaining portion of the aqua-ammonia solution and the concentrated ammonia with CO2 to form a stream rich in urea (CH4N2O); d. separating an aqueous solution of urea from a stream rich in urea; e. combining the aqueous solution of urea with aqueous solution of nitric acid (HNO3) to form urea ammonium nitrate (UAN) solutions. A different embodiment is directed to a method for making ammonia, the method comprising: a. mixing H2 with N2 to create a mixed stream; b. de-hydrating the combination of the mixed stream and a recycle stream to create a dry stream; c. reacting the H2 and N2 contained in the dry stream in a synthesis reactor to form an effluent stream comprising ammonia (NH3); d. absorbing NH3 from the effluent stream in water to generate an aqua-ammonia solution and the recycle stream that contains the unreacted H2 and N2; e. separating a fraction of the recycle stream to create a purge stream to control the accumulation of any inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product; g. using the heat generated by the ammonia synthesis reactor to power the dehydration and / or the distillation; h. oxidizing a portion of the aqua-ammonia solution and the concentrated ammonia to form a NOx stream rich in nitrogen oxides (NOx); i. absorbing NO2 from the NOx stream in water to generate an aqueous solution of nitric acid (HNO3) and a vapor stream; j . reacting the remaining portion of streams the aqua-ammonia solution and the concentrated ammonia with CO2 to form an effluent stream rich in urea (CH4N2O); k. separating an aqueous solution of urea from a stream rich in urea; l. combining the aqueous solution of urea with aqueous solution of nitric acid (HNO3) to form urea ammonium nitrate (UAN) solutions

[0046] Also provided is a system configured to perform any of the foregoing methods It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of subject matter within this disclosure are contemplated as being part of the inventive subject matter disclosed herein.

[0047] Still other aspects, examples, and advantages of these exemplary aspects and examples, are discussed in detail below. Moreover, it is to be understood that both the foregoing information and the following detailed description are merely illustrative examples of various aspects and examples, and are intended to provide an overview or framework for understanding the nature and character of the claimed aspects and examples. Any example disclosed herein may be combined with any other example in any manner consistent with at least one of the objects, aims, and needs disclosed herein, and references to “an example,” “some examples,” “an alternate example,” “various examples,” “one example,” “at least one example,” “ this and other examples” or the like are not necessarily mutually exclusive and are intended to indicate that a particular feature, structure, or characteristic described in connection with the example may be included in at least one example. The appearances of such terms herein are not necessarily all referring to the same example.

[0048] FIGURES

[0049] FIG. 1 shows an example of the systems and methods described herein for production of renewable ammonia.

[0050] FIG. 2 shows another example of the systems and methods described herein for production of renewable ammonia with co-production of noble gases.

[0051] FIG. 3 shows another example of the systems and methods described herein for production of renewable ammonia with co-production of power and heat.

[0052] FIG. 4 shows an example of the systems and methods described herein for production of renewable nitric acid and / or ammonium nitrate solutions.

[0053] FIG. 5 shows an example of the systems and methods described herein for production of urea.

[0054] FIG. 6 shows an example of the systems and methods described herein for production of UAN.

[0055] FIG. 7 shows an example of the systems and methods described herein for production of UAN using exogenously-produced urea.

[0056] FIG. 8 shows an example of the systems and methods described herein for production of UAN using exogenously-produced ammonium nitrate.

[0057] FIG. 9 shows an example of the systems and methods described herein for production of UAN using exogenously-produced nitric acid.

[0058] FIG. 10 shows an example of the systems and methods described herein for production of UAN using exogenously-produced nitric acid and urea. DESCRIPTION

[0059] The production of synthetic ammonia and its derivatives has been one of the key enablers of the global development of intensive agriculture. It is estimated that, without synthetic nitrogen fertilizers, the world would require three to four times more arable land to sustain current food production requirements.

[0060] The commercial production of synthetic ammonia was enabled by the discovery of ironbased catalysts capable of reacting hydrogen with nitrogen at industrially viable conditions, usually at pressures of few hundred atmospheres and temperatures above 400 °C. In this traditional process, the hydrogen feed is generated via steam reforming of hydrocarbons, natural gas being the most common hydrocarbon utilized. The nitrogen is introduced into the process in the form of air and the oxygen is combusted with a fraction of the hydrocarbons to generate part of the heat required by steam reforming.

[0061] The basic process described above has not changed in any significant way since the first commercial production of synthetic ammonia many decades ago. Over the years, the technology development has proceeded in two main directions: (a) a continuous optimization to achieve an incrementally improved utilization of the energy contained in the hydrocarbon feed via more and more sophisticated heat and mass integration; and (b) a continuous scale-up effort to increase the maximum single train size to the current world scale capacities above 3,500 metric tons per day (MTD).

[0062] The commercial manufacturing processes that have resulted from these two development strategies cannot be easily adapted and deployed for the production of renewable ammonia, especially if the hydrogen feed is generated via water electrolysis powered with renewable energy. In fact, ammonia production from renewable power does not include a hydrocarbon feed and is typically very distributed in nature.

[0063] In contrast, the process described herein produces hydrogen (H2) (e.g., from geologic sources or using electrolysis), enriches nitrogen (N2) to a concentration of at least about 95%; deoxygenates and combines the H2 and the N2 to produce a feedstock stream; and synthesizes NH3 from the feedstock stream in a synthesis reactor at a pressure below about 80 bar.

[0064] In an aspect, provided herein is a method for making nitrogenous products. The method can include providing hydrogen (H2). The hydrogen can come from geologic sources or by electrolyzing water (H2O) to produce hydrogen (H2) and oxygen (O2). The process can include reacting the H2 with nitrogen (N2) to form ammonia (NH3), and using the O2 from electrolysis (in addition to O2 from air), oxidizing the NH3 to form nitrate (NO3 ). The nitrate can be in the form of ammonium nitrate (NH4NO3) and / or nitric acid (HNO3). In some embodiments, the method further comprises reacting carbon dioxide (CO2) with the ammonia (NH3) to form urea and blending such urea with the nitrate (NOf) to form UAN solutions.

[0065] In another aspect, provided herein is a system for making nitrogenous products. The system can comprise an electrolyzer configured to electrolyze water (H2O) to produce hydrogen (H2) and oxygen (O2), a reactor configured to react the H2 with nitrogen (N2) to form ammonia (NH3), and an oxidizer configured to use O2 from air and, possibly, the O2 from electrolysis to oxidize the NH3 to form nitrate (NO3 ).

[0066] With reference to FIG. 1, the system described herein for nitrogenous products can include an air separation unit 101, an electrolyzer 106, an ammonia synthesis module 113, an ammonia absorption module 114, and an ammonia distillation module 117.

[0067] An air separation module 101 can be configured to separate air 100 into a first stream comprising oxygen (O2) 102 and a second stream comprising nitrogen (N2) 103. The air separation module can be based on membranes, pressure swing adsorption, cryogenic liquefaction and distillation, or any other technology to separate nitrogen and / or oxygen from air. The system can include an electrolysis module 106 that is configured to use electrical power 105 to split water (H2O) 104 into a third stream comprising O2 108 and a fourth stream comprising hydrogen (H2) 107. The system can further include a de-oxygenation module 109 that is configured to remove oxygen from the second stream and / or the fourth stream. The mixture of H2 and N2 (wet syngas) from the deoxygenation module still contains water, which can be removed in a dehydration module 111. De-hydration can be performed either by adsorbing water on a sorbent or by contacting the wet gaseous stream with a pure ammonia stream (ammonia wash). In the first case, module 111 would typically consist of a number of vessels containing a water sorbent, for example a molecular sieve, which are alternatively operated to dry the wet syngas or being regenerated. The regeneration of the dehydration module is performed by heating the sorbent either by flowing a hot fluid (for example, the purge gas stream 120) or by directly heating the sorbent bed with an immersed heating element. If an ammonia wash design is adopted, module 111 would typically consist of a gas-liquid contactor (for example, a packed column or a simple inline mixer) where a fraction of the liquid ammonia 119 is contacted with the wet gaseous stream to generate a dry vapor - which will contain ammonia - and a concentrated ammonia solution, which would be combined with the rich aqua-ammonia solution 116 Ammonia can be synthesized by reacting the dried mixture of N2 and H2 in the ammonia synthesis module 113, which comprises a synthesis reactor configured to operate at a pressure below about 80 bar.

[0068] The system can further comprise an absorption module 114 configured to absorb the NH3 contained in the synthesis module effluent into a lean aqueous stream of ammonia 118. The absorption module can use any typical gas-liquid contactor, such a packed column or a trayed tower, and adequate cooling needs to be provided to remove the heat of reaction generated by the dissolution of NH3 in H2O. Such cooling can be provided via coils immersed in the absorption module 114 or via external heat exchangers where fractions of the liquid flowing in the absorption module are cooled (pump-arounds). The absorption module produces a rich aqueous solution of ammonia 116 with a typical concentration of 15% to 30% ammonia by weight, and a gaseous stream 115 (wet recycle) that contains the unconverted H2 and N2, water and traces of ammonia. Such stream is recycled to the de-hydration module 111 via a simple compressor, typically a single-stage centrifugal or reciprocating unit.

[0069] The system can further comprise an ammonia distillation module 117 configured to remove water from the rich aqueous solution 116 and generate a product stream 119, which can have an ammonia concentration as high as 99.95% by weight. The distillation module also generate the lean aqueous solution 118 used in the absorption module. The distillation module can use any typical gas-liquid contactor, such as a packed column or a trayed tower, equipped with an appropriate reboiler - to partially evaporate the bottom liquid stream - and an overhead condenser to condense the vapors at the top.

[0070] The energy required by the distillation module 117 is supplied by any combination of reaction heat from the synthesis module 113 (the reaction of H2 and N2 is exothermic) and externally supplied heat, for example from an electric heater or a gas fired heater. Also, energy can be supplied to the distillation module from waste heat generated by another process, such as a power generation unit.

[0071] A Hydrogen Recovery Unit (HRU module 121) can be added to the system to recover the H2 contained in the purge stream 120. Typically, such module would consist of a membrane unit that permeates a H2 stream (low pressure product) and rejects all other molecules in the purge stream - usually N2, CH4 (if present) and inert gases such as helium (He) and argon (Ar). The H2 product stream would be compressed and recycled to the ammonia synthesis module 113; such compression can be powered by the expansion of the reject stream 123. Alternatively, module 121 can consist of a different type of unit operation - for example, a Pressure Swing Adsorption (PSA) - where the H2 product stream is at the same pressure of the purge stream 120 (minus the pressure drop of the unit itself). In this case, the H2 product stream can be directly fed to the ammonia synthesis module 113 if the purge stream is extracted downstream of the circulator while the H2 stream is recycled upstream of such circulator. In yet another design, HRU module 121 can be a cryogenic unit where H2 and, possibly, N2 are separated via distillation from the other molecules, such as Ar, He and CH4, and recycled to the ammonia synthesis module.

[0072] The systems and methods described herein can be used to produce an aqueous solution of ammonia with any desired ammonia concentration: the distillation module 117 can be designed to enrich the ammonia to any desired concentration, optionally anhydrous ammonia with commercial specification (>99.5% NH3, >0.1% H2O). Distillation requires energy input, however that energy can be provided from exothermic reactions within the process, and such heat can be captured in a hot oil, hot water, or steam system, or directly supplied to the distillation reboiler by feeding the reboiler itself with the hot stream from which the heat can be recovered (e.g., the reactor effluent from module 113).

[0073] In some cases, the pressure at the electrolyzer outlet is less than the pressure of the ammonia synthesis reactor. In such cases, a boost compressor can be used to increase the pressure prior to the ammonia synthesis reactor. The pressure at the electrolyzer outlet can be any suitable pressure, such as about 5 bar, about 15 bar, about 20 bar, about 25 bar, about 30 bar, about 35 bar, about 40 bar, about 50 bar, about 60 bar, or about 80 bar. In some instances, the outlet pressure of the electrolyzer is between about 20 and about 30 bar. The electrolyzer can be a polymer electrolyte membrane (PEM) or alkaline electrolyzer.

[0074] The hydrogen required for the ammonia synthesis can be provided by an electrolyzer, which utilizes electric power to convert water into hydrogen and oxygen. The ammonia product can be considered renewable if a portion of the power fed to the electrolyzer originated entirely or partly from a renewable source or carbon free source such as nuclear power, or if such power is sourced from the grid or any other source in combination with the acquisition of renewable power credits or similar financial instruments. For the systems and methods described herein, the electrolyzer does not require a hydrogen purification unit to remove oxygen impurities, as the final oxygen removal is performed in the de-oxygenation (aka, hydrogenation) reactor. However, in some embodiments a hydrogen purification unit may be beneficial.

[0075] The nitrogen required for the ammonia synthesis can be generated from the separation of nitrogen from air or from the enrichment of nitrogen in air. For example, such enrichment can be obtained via the use of the membranes, which can produce a stream with nitrogen in excess of 80 %mol. Alternatively, a pressure swing adsorber (PSA) or vacuum PSA (VPSA) can also be utilized to produce a nitrogen rich stream with a nitrogen concentration in excess of 80 %mol. Alternatively, an Air Separation Unit (ASU) can also be utilized to separate nitrogen from air via air liquefaction and / or distillation. Any other means of separating nitrogen from air or enriching nitrogen in air can be utilized for this process having the nitrogen concentration in the resulting stream is above 80%mol.

[0076] In some cases, the nitrogen concentration is about 80%, about 85%, about 90%, about 95%, about 97%, about 99%, about 99.5%, about 99.9%, about 99.95%, or about 99.99%. In some instances, the nitrogen concentration is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 97%, at least about 99%, at least about 99.5%, at least about 99.9%, at least about 99.95%, or at least about 99.99%.

[0077] The hydrogen and nitrogen streams can be mixed together to produce the raw synthesis gas ("syngas") stream, which contains oxygen in addition to hydrogen, nitrogen and other minor impurities. As used herein, the term "syngas" describes a gas stream that is used to make ammonia. The syngas used herein does not typically contain appreciable amounts of carbon monoxide (CO). The raw syngas is pre-heated to the inlet temperature required by the deoxygenation reactor, usually a temperature between ambient and 300 °C depending on the exact type and composition of the hydrogenation catalyst utilized. The pre-heating can be performed either with an external source of energy (for example, an electric heater) or by recovering heat from an appropriate stream within the process via heat exchange.

[0078] The de-oxygenation reactor can be a fixed bed reactor that employs a standard hydrogenation catalyst, such as the ones utilized for hydrogen purification from electrolytic cells. For example, a catalyst containing platinum or palladium is conventionally utilized for these applications. The design of the reactor can be single-stage adiabatic, for example, a vessel containing one type of catalyst. Alternatively, it can be a multi-stage adiabatic reactor, for example with multiple sections of catalyst (either the same catalyst or optionally different catalysts optimized for each section of the reactor), in series with heat exchangers in between each catalyst bed. It can also bean isothermal or pseudo-isothermal reactor, including any means of providing heat exchange inside the catalytic bed. In some embodiments the reactor can also be a combination of such designs.

[0079] The effluent from the de-oxygenation reactor can be the wet syngas stream, which contains hydrogen, nitrogen, minor impurities and the water generated by the combination of hydrogen and oxygen in the reactor. The wet syngas stream can be cooled to ambient temperature via heat exchange with other process streams, water cooling, air cooling, direct quench with water or even below ambient temperature by heat exchange with another cold fluid (such as ammonia or any ammonia containing stream), or any combination thereof. The wet syngas stream can be dried.

[0080] Water can be removed from the wet syngas. In some cases, the syngas is dried in a dehydration unit, which is operated in a Temperature Swing Adsorption (TSA) cycle. Two or more vessels can be filled with sorbent material (such as molecular sieve) that has a high affinity to water. One or more vessels can be operated in adsorption mode where the water in the wet syngas is adsorbed by the sorbent while the gas stream flows through the bed. Once the sorbent is saturated with water, the vessels can be switched to the regeneration mode. While some vessels are operated in adsorption mode, the remaining are operated in regeneration mode where the purge gas stream is heated to a suitable temperature (usually between 150 and 350 °C) and passed over the saturated sorbent material to evaporate the water contained in the sorbent. The location of the purge extraction in the synthesis loop can vary depending on the specific design and operating conditions. For example, the purge can be extracted from the effluent downstream of the absorber or from the dry syngas produced by the dehydration unit itself.

[0081] The dry syngas stream can be fed to the ammonia synthesis reactor without the risk of damaging or poisoning the ammonia synthesis and / or catalyst, which can be sensitive to oxygenated compounds. Several designs can be adopted for the ammonia synthesis reactor. In some cases, a multistage adiabatic reactor with multiple layers of catalyst can be separated by heat exchangers. The catalyst beds can be contained in separate vessels or in a single vessel and the heat exchangers can be external to the vessels or contained inside them. The catalytic beds can have an axial, axial-radial or radial design. In some cases, the reactor is an axial reactor.

[0082] In some cases, the reactor is a pseudo-isothermal reactor with one or more layers of catalyst that feature heat exchange elements inserted in the catalytic bed, such as tubes or plates. The catalyst beds can be contained in separate vessels or in a single vessel and can have an axial, axial-radial or radial design. In some cases, the reactor is an axial reactor.

[0083] The synthesis reactor used in the methods described herein can have a hot shell. In a hot shell reactor, the catalyst is in direct contact with a pressure vessel. This can be achieved here because of operation of the synthesis at a lower pressure (and lower temperature). This is in contrast to the more costly cold shell reactors that separate the catalyst from the pressure vessel. The pressure vessel can safely contain hydrogen at the equilibrium temperature of the ammonia synthesis reaction. The synthesis reactor can be an axial reactor. An axial reactor can flow gas downward relative to the catalyst bed.

[0084] The ammonia synthesis catalyst can comprise iron oxide. In some cases, the iron oxide comprises wustite. The catalyst can contain any suitable promoter, diluent, binder, excipient, and can be formed into any suitable form. In some cases, the catalyst has a pellet diameter of about 10 millimeters (mm), about 7 mm, about 5 mm, about 3 mm, about 2 mm, or about 1 mm. In some cases, the catalyst has a pellet diameter of less than about 10 millimeters (mm), less than about 7 mm, less than about 5 mm, less than about 3 mm, less than about 2 mm, or less than about 1 mm. In contrast, world-scale designs typically use radial reactors in order to achieve a high cross section. The reactor designs described herein are uniquely available to use these small catalyst forms.

[0085] The synthesis of NH3 can be done at any suitable pressure. In some cases, the synthesis reactor is operated at a pressure of about 100 bar, about 80 bar, about 70 bar, about 60 bar, about 50 bar, about 40 bar, or about 30 bar. In some cases, the synthesis reactor is operated at a pressure of less than about 100 bar, less than about 80 bar, less than about 70 bar, less than about 60 bar, less than about 50 bar, less than about 40 bar, or less than about 30 bar.

[0086] The ammonia synthesis reactor effluent can be cooled via heat exchange with another process stream or with an external stream, such as water or air, or any combination thereof. Additional cooling can be provided with direct injection of cold ammonia into the reactor effluent (i.e., direct quenching) or via an ammonia chiller (e.g., indirect cooling generated by ammonia evaporation with the vapors).

[0087] Depending on the operating pressure and temperature of the ammonia reactor effluent, a portion - ranging between 0% and 80% - of the ammonia contained in the reactor effluent can condense and form the liquid stream of anhydrous ammonia, which is separated from the syngas stream in a gas-liquid separator. The remaining ammonia contained in the reactor effluent is absorbed in the water absorption system, which produces a rich aqua-ammonia stream with an ammonia concentration of at least 5% by weight. This aqua-ammonia stream can be distilled to generate a more concentrated aqua-ammonia stream with a concentration ranging from 20% to 99.5% by weight. The operating pressure of the distillation section would be chosen such that the boiling point of the overhead vapor stream is higher than typical ambient temperature or the temperature of the most readily available cooling stream, such as cooling water. In this way the concentrated aqua-ammonia stream leaving the distillation overhead can be simply condensed either with an air or a water cooler. The lean aqua-ammonia stream leaving the bottom of the column would be partially vaporized in a reboiler to generate the required vapor reflux, while the separated boiling liquid would be cooled and recycled to the absorption system or otherwise disposed of.

[0088] The process can be operated with a recycle loop, for example, by recirculating nonreacted H2 and N2 leaving the absorption system to the synthesis reactor. The recirculated H2 and N2 can be pressurized to a pressure of the synthesis reactor using a single-stage compressor called circulator and then heated to the temperature required by the ammonia synthesis reactor. By adopting an absorption method to separate NH3 from the synthesis reactor effluent, it can be recognized that the recirculated stream will contain less than 1% - and typically less than 0.1% - NH3, which enables the reactor to achieve a high conversion even at pressures below 80 bar.

[0089] The method shown in FIG. 2 can produce aqua-ammonia or ammonia as a product in combination with the production of noble gases - such as Ar and / or He originally contained either in the H2 or N2 feed streams - and the recovery of N2 from the purge stream. In FIG. 2, like numbers denote like elements to FIG. 1. However, here, the purge stream 120 can be fed to a Hydrogen Recovery Unit (HRU) 121 where H2 contained in the purge is separated from the other molecules and recycled to the ammonia synthesis reactor. Depending on the HRU design, no less than 40% and, usually, more than 80% of the H2 in the purge is recovered and recycled to the ammonia synthesis reactor. In the case that the HRU module 121 is a membrane or a PSA or similar separation device, the offgas stream 123 can be further processed in a new separation unit 124 designed to separate N2 from all other molecules. For example, unit 124 can be a PSA designed to separate Ar and / or He from N2, in which case the N2 effluent stream is recycled to the ammonia synthesis module while the other effluent stream would be recovered as a product gas concentrated in Ar and / or He. For example, a conventional PSA can generate a product gas stream with a concentration of at least 30% and typically more than 90% of Ar and / or He.

[0090] In some cases, a combustion unit (e.g., a burner or a catalytic oxidizer) can be added downstream of the HRU 121 and upstream of the separation module 124 to convert all remaining H2 into water, which can be separated via phase condensation and de-hydration prior to processing the reject stream 123 in the separation unit 124.

[0091] In FIG. 3, like numbers denote like elements to FIG. 1 and FIG. 2. However, here, the purge stream 120 can be fed to a Power Generation Unit 121 where H2 contained in the purge is reacted with the Ch-containing stream 127, which could be air, enriched air - for example, the tail gas of an Air Separation Unit or a N2 Generation Unit (N2 PSA) - to generate power. The H2 combustion can take place in a fuel cell, an internal combustion engine, a gas turbine or a linear generator (such as a Mainspring unit). Depending on the Power Generation module design, it may be possible to recover heat from the exhaust of the module and such heat can be used to fuel modules 111 or 117. Once cooled to about ambient temperature, the exhaust stream 123 can be fed to a suitably designed separation module 124 to, first, dehydrate the stream (if needed by the downstream unit) and then separate N2 from all remaining molecules, mostly noble gases such as Ar and / or He that are recovered as the product stream 126. For example, a conventional PSA can generate a product gas stream with a concentration of at least 30% and typically more than 90% of Ar and / or He. The N2 stream 125 is recycled to the ammonia synthesis module. It can also be appreciated that, in certain cases, the Power Generation Unit 121 can be sized in such a way that all the N2 required for ammonia synthesis is provided from stream 127 via module 124, thus eliminating the need for stream 102 and any upstream equipment required to produce it.

[0092] FIG. 4 shows methods to produce nitric acid (HNO3) or ammonium nitrate (NH4NO3). In FIG. 4, like numbers denote like elements to FIG. 1, FIG. 2 and FIG. 3. The O2 from the electrolyzer (and / or from the air separation unit) can be used to oxidize the NH3 to nitrogen oxides (NOx) in addition to or as a replacement of air, especially in the case where a different inert than N2 is used to dilute the reactants in the NH3 oxidation module 130 (for example, in the case where the NH3 feed to the module 130 combined with CO2, which can act as an inert in the NH3 oxidation process). The NH3 can be oxidized by reacting it with oxygen in the presence of a catalyst. The catalyst can comprise a platinum group metal and optionally rhodium. In some cases, the catalyst comprises cobalt. The reaction of NH3 with O2 is highly exothermic and is usually conducted at temperatures above 600 C. Such reaction heat can be recovered in a suitably designed heat exchanger to heat an intermediate heat storage medium (such as hot oil or water) or to generate steam. Such recovered heat can be fed to units 111 or 117, or anywhere else in the process where heat is required.

[0093] In some embodiments, as shown in FIG. 4, the method further comprises cooling the effluent from module 130 and absorbing it in water in a suitable absorption tower 132. In some embodiments, the O2 derived from electrolysis can be used to oxidize and / or ozonate nitrogen oxides such as nitrous oxide (N2O) and nitric oxide (NO) to nitrogen dioxide (NO2). In these embodiments the O2 may be partially converted to ozone in a separate ozonator prior to being injected downstream of module 130.

[0094] The HNO3 solution generated by the dissolution of NO2 in water can be reacted with NH3 in the neutralization reactor 134 to produce the NH4NO3 solution 135. Such neutralization reaction is also highly exothermic and the reaction heat can be recuperated to feed other sections of the process. Alternatively, it can be recognized that the neutralization heat can be utilized to enable the feeding of the oxidation module 130 with the rich aqua-ammonia stream 116 because such reaction heat causes a large amount of the water contained in stream 116 to evaporate, thus generating the concentrated aqueous solution of NH4NO3 135. In some embodiments the stream 135 is further fed to a downstream module - such as a prilling tower - to evaporate all water and produce a solid ammonium nitrate product.

[0095] The vapor stream 136 leaving module 132 contains N2, N2O and the non-dissolved NOx. A purification module 137 can be added to the system to convert all nitrogenous compounds in stream 136 to N2 - for example, via a catalytic converter and / or a Selective Catalytic Reduction (SCR) system - and / or separate N2 from all remaining molecules. This pure N2 stream can then be recycled to the ammonia synthesis sytem.

[0096] FIG. 5 shows methods to urea (CH4N2O). In FIG. 5, like numbers denote like elements to FIG. 1, FIG. 2, FIG. 3 and FIG. 4. Any combination of the rich aqua-ammonia stream 116 and NH3 stream 119 can be fed to a urea synthesis module 140. In this module NH3 readily reacts with CO2 to form carbamate, which then spontaneously converts to urea until the thermodynamic equilibrium is achieved. The CO2 stream 141 can be derived from several sources, including, but not limited to, pipelines, natural gas processing plants, hydrocarbonbased ammonia plants, flue gas, fermentation of biomass (for example, com for ethanol production), incineration or gasification of waste, directly from the atmosphere via Direct Air Capture (DAC), or any other industrial or natural source.

[0097] The urea synthesis module 140 typically consists of a reactor operating at pressures above 150 bar, as high as 300 bar, with a stochiometric mixture of NH3 and CO2. In some embodiments an excess CO2 can be utilized to maximize the conversion of NH3 to carbamate and urea. In some embodiments the module 140 also includes high pressure strippers and / or condensers to separate and directly recycle unconverted NH3 and CO2 to the urea synthesis reactor.

[0098] The product of module 140 is a mixture of urea, carbamate, NH3, CO2 and water. Modules 142 and 144 utilize sequences of several different unit operations at decreasing pressures - such as carbamate decomposers, strippers, and other separation units - to recover the concentrated urea solution 143 (typically with a concentration 70-80% of urea in water) and recycle the unconverted CO2 and NH3 to the reactor with any remaining carbamate. In some embodiments the urea solution 143 is further concentrated - usually in a vacuum condenser - and successively prilled or granulated to generate a solid urea product. In FIG. 6, like numbers denote like elements to FIG. 1, FIG. 2, FIG.3, FIG. 4 and FIG. 5. Here, the methods described in FIG. 4 and FIG. 5 are combined to produce the urea ammonium nitrate (UAN) product 151 by blending the ammonium nitrate solution 135 and the urea solution 143 in a suitably designed mixing module 150. Module 150 usually consists of a mixing tank, sometimes cooled with immersed cooling elements (such as coils) or external exchangers. Corrosion inhibitors and other additives can be added to the UAN product 151 to improve its stability and reduce its corrosivity.

[0099] The method described herein provides a more efficient route to nitrogenous products such as UAN than admixing solid urea and solid ammonium nitrate in water. In another aspect, provided herein is a method for producing nitrogenous products comprising forming a solution comprising a composition substantially similar to 20% water (H2O), 40% ammonium nitrate (NH4NO3), and 40% urea (CH4N2O) by mass, where the solution is formed without mixing solid urea with solid ammonium nitrate. In some cases, none of the concentrations of H2O, NH4NO3 and CH4N2O vary by more than 30% in the solution. In some embodiments, none of the concentrations of H2O, NH4NO3 and CH4N2O vary by more than 10% in the solution.

[0100] The ammonium nitrate required for the process described in FIG. 6 can be provided from external sources. Similarly, the urea required for the process described in FIG. 6 can be provided from external sources. For example, in FIG. 7, FIG. 8, FIG. 9, and FIG. 10, like numbers denote like elements to FIG. 1, FIG. 2, FIG.3, FIG. 4, FIG. 5 and FIG. 6.

[0101] Turning to FIG. 7, shown here is an example of the systems and methods described herein for production of UAN using exogenously-produced urea. Here, urea 152 (e.g., that is sourced and / or produced exogenously from the systems and methods described herein) can be used, e.g., in the production of UAN according to the systems and methods described herein. The urea 152 can be mixed 154 with water 156 to produce a urea solution 143. The process then proceeds as described herein.

[0102] Turning to FIG. 8, shown here is an example of the systems and methods described herein for production of UAN using exogenously-produced ammonium nitrate. Here, ammonium nitrate 158 (e.g., that is sourced and / or produced exogenously from the systems and methods described herein) can be used, e.g., in the production of UAN according to the systems and methods described herein. The ammonium nitrate (AN) 158 can be mixed with water 160 to produce an ammonium nitrate (NH4NO3) solution 135. The process then proceeds as described herein. Turning to FIG. 9, shown here is an example of the systems and methods described herein for production of UAN using exogenously-produced nitric acid. Here, nitric acid 162 (e.g., that is sourced and / or produced exogenously from the systems and methods described herein) can be used, e.g., in the production of UAN according to the systems and methods described herein. The nitric acid (HNO3) 162 can be mixed with water 164 to produce a nitric acid (NNO3) solution 133. The process then proceeds as described herein.

[0103] Turning to FIG. 10, shown here is an example of the systems and methods described herein for production of UAN using exogenously-produced nitric acid and urea. Here, nitric acid 162 (e.g., that is sourced and / or produced exogenously from the systems and methods described herein) can be used, e.g., in the production of UAN according to the systems and methods described herein. The nitric acid (HNO3) 162 can be mixed with water 164 to produce a nitric acid (NNO3) solution 133. Furthermore, urea 152 (e.g., that is sourced and / or produced exogenously from the systems and methods described herein) can be used, e.g., in the production of UAN according to the systems and methods described herein. The urea 152 can be mixed with water 156 to produce a urea solution 143. The process then proceeds as described herein.

[0104] In some cases, the only inputs in this process are air, water, CO2 and electric power and the end products are aqueous and anhydrous ammonia, which can be generated in any combination depending on the design and operating parameters selected for the process.

[0105] The system can consume about 300 megawatts (MW), about 200 MW, about 100 MW, about 80 MW, about 80 MW, about 60 MW, about 40 MW, about 20 MW, or about 10 MW of electrical power per year. In some instances, the system consumes less than about 300 megawatts (MW), less than about 200 MW, less than about 100 MW, less than about 80 MW, less than about 80 MW, less than about 60 MW, less than about 40 MW, less than about 20 MW, or less than about 10 MW of electrical power per year.

[0106] The systems described herein can have any suitable capacity for producing nitrogenous products. In some cases, the system has a capacity for producing NH3 of about 1,000, about 5,000, about 10,000, about 50,000, about 100,000 or about 1,000,000 metric tons per year. In some embodiments, the system has a capacity for producing nitrogenous products of at least about 1,000, at least about 5,000, at least about 10,000, at least about 50,000, or at least about 100,000 metric tons per year. In some cases, the system has a capacity for producing nitrogenous products of at most about 1,000, at most about 5,000, at most about 10,000, at most about 50,000, or at most about 100,000 metric tons per year. The above-described embodiments can be implemented in any of numerous ways. For example, the embodiments may be implemented using hardware, software or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers. It should be appreciated that any component or collection of components that perform the functions described above can be generically considered as one or more controllers that control the above-discussed functions. The one or more controllers can be implemented in numerous ways, such as with dedicated hardware or with one or more processors programmed using microcode or software to perform the functions recited above.

[0107] In this respect, it should be appreciated that one implementation of the embodiments of the present invention comprises at least one non-transitory computer-readable storage medium (e.g., a computer memory, a portable memory, a compact disk, etc.) encoded with a computer program (i.e., a plurality of instructions), which, when executed on a processor, performs the above-discussed functions of the embodiments of the present invention. The computer-readable storage medium can be transportable such that the program stored thereon can be loaded onto any computer resource to implement the aspects of the present invention discussed herein. In addition, it should be appreciated that the reference to a computer program which, when executed, performs the above-discussed functions, is not limited to an application program running on a host computer. Rather, the term computer program is used herein in a generic sense to reference any type of computer code (e.g., software or microcode) that can be employed to program a processor to implement the above-discussed aspects of the present invention.

[0108] Various aspects of the present invention may be used alone, in combination, or in a variety of arrangements not specifically discussed in the embodiments described in the foregoing and are therefore not limited in their application to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments.

[0109] Also, embodiments of the invention may be implemented as one or more methods, of which an example has been provided. The acts performed as part of the method(s) may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments. Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed. Such terms are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term).

[0110] The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," "having," “containing”, “involving”, and variations thereof, is meant to encompass the items listed thereafter and additional items.

[0111] The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and / or listed in the Application Data Sheet, including U.S. Provisional Patent Application No. 63 / 508,226, filed on June 14, 2023, to which this application claims priority, are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.

[0112] Having described several embodiments of the invention in detail, various modifications and improvements will readily occur to those skilled in the art. Such modifications and improvements are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only, and is not intended as limiting. The invention is limited only as defined by the following claims and the equivalents thereto.

Claims

CLAIMSWhat is claimed is:

1. A method for making ammonia, the method comprising: a. mixing (H2) with nitrogen (N2) to create a mixed stream and optionally treating the mixed stream in a de-oxidation reactor to remove remaining oxygen (O2); b. de-hydrating a combination of the mixed stream and a recycle stream to create a dry stream; c. reacting the H2 and N2 contained in the dry stream in a synthesis reactor to form an effluent stream containing ammonia (NH3); d. absorbing NH3 from the effluent stream in water to generate an aqua-ammonia solution and a the recycle stream, which recycle stream contains unreacted H2 and N2 and is combined with the mixed stream; e. separating a fraction of the recycle stream to create a purge stream to control accumulation of inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product; and g. using the heat generated by the ammonia synthesis reactor to power the dehydration and / or the distillation.

2. The method of Claim 1, wherein the hydrogen (H2) is provided from a geologic source.

3. The method of Claim 1, wherein the hydrogen (H2) is provided from an electrolyzer that is powered using renewable power.

4. The method of Claim 3, wherein the electrolyzer further produces oxygen (O2) and the method further comprises mixing H2 with N2 and treating such mixed stream in a deoxidation reactor to remove remaining O2.

5. The method of Claim 1, wherein a production rate of ammonia is increased or decreased in response to a price or availability of renewable power.

6. The method of Claim 1, wherein the N2 is produced by cryogenic air liquefaction and distillation.

7. The method of Claim 1, wherein the N2 is produced by Pressure Swing Adsorption (PSA).

8. The method of Claim 1, wherein the N2 is produced in a selectively permeable membrane.

9. The method of Claim 1, wherein the de-hydration is performed with Temperature Swing Adsorption (TSA).

10. The method of Claim 1, wherein the de-hydration is performed by contacting the wet gas mixture with a molecular sieve material.

11. The method of Claim 1, wherein the de-hydration is performed by contacting the wet gas mixture with an aqueous solution of ammonia or with liquid ammonia.

12. The method of Claim 1, wherein the NH3 is synthesized in a reactor at a pressure below about 80 bar.

13. The method of Claim 1, wherein the NH3 is synthesized in a reactor at a pressure below about 60 bar.

14. The method of Claim 1, wherein the NH3 is synthesized in a reactor at a pressure of about 40 bar.

15. The method of Claim 1, wherein the NH3 is synthesized in a reactor at a pressure below about 40 bar.

16. The method of Claim 1, wherein the NH3 is synthesized in the presence of a catalyst, which catalyst is in direct contact with a pressure vessel.

17. The method of Claim 1, wherein the NH3 is synthesized in the presence of a catalyst, which catalyst is contained in tubes inside a vessel.

18. The method of Claim 1, wherein a portion of the NH3 contained in the effluent stream is condensed and separated and the remaining portion is absorbed in water.

19. The method of Claim 1, wherein the NH3 in the effluent stream is absorbed in water using a column filled with packing.

20. The method of Claim 1, wherein the NH3 in the effluent stream is absorbed in water using a column equipped with trays.

21. The method of Claim 1, wherein the aqua-ammonia solution is distilled using a column filled with packing.

22. The method of Claim 1, wherein the aqua-ammonia solution is distilled using a column equipped with trays.

23. The method of Claim 1, wherein the distillation of the aqua-ammonia solution is at least partially powered by an external source of heat.

24. The method of Claim 1, wherein formation of the NH3 produces heat, which heat is captured in a hot oil, hot water, or steam system.

25. The method of Claim 1, wherein the H2 contained in the purge stream is separated and recycled to ammonia synthesis.

26. The method of Claim 1, wherein the H2 contained in the purge stream is separated, further compressed, and recycled to ammonia synthesis.

27. The method of Claim 1, further comprising: a. separating the purge stream into a concentrated H2 stream and a tail gas stream that contains non-reactive species (e.g., N2, CH4 if present in the system, and noble gases Ar and He); b. recycling the purge stream to the ammonia synthesis; c. concentrating Ar and / or He from the teal gas stream to create a product stream.

28. A method for making ammonia, the method comprising: a. mixing H2 with N2 to create a mixed stream; b. de-hydrating the mixed stream stream and a recycle stream to create a dry stream; c. reacting the H2 and N2 contained in the dry stream in a synthesis reactor to form an effluent stream containing ammonia (NH3); d. absorbing NH3 from the effluent stream in water to generate an aqua-ammonia solution and a recycle stream that contains the unreacted H2 and N2; e. separating a fraction of the recycle stream to create a purge stream to control the accumulation of any inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product; g. using heat generated by the ammonia synthesis reactor to power the de-hydration and / or the distillation; h. separating the purge stream into a concentrated H2 stream and a tail gas stream that contains all non-reactive species (N2, CH4 if present in the system, and noble gases Ar and He); i. recycling the purge stream to the ammonia synthesis; j . concentrating Ar and / or He from the tail gas stream to create a product stream.

29. The method of Claim 28, wherein H2 is separated from the purge stream via cryogenic distillation.

30. The method of Claim 28, wherein H2 is separated from the purge stream via Pressure Swing Adsorption (PSA).

31. The method of Claim 28, wherein H2 is separated from the purge stream in a selectively permeable membrane.

32. The method of Claim 28, wherein Ar and / or He are separated from the tail gas stream via cryogenic distillation.

33. The method of Claim 28, wherein Ar and / or He are separated from the tail gas stream via Pressure Swing Adsorption (PSA).

34. The method of Claim 28, wherein Ar and / or He are separated from the tail gas stream in a selectively permeable membrane.

35. The method of Claim 34, wherein the tail gas stream is recycled to ammonia synthesis after removal of Ar and / or He.

36. The method of Claim 28, further comprising: a. feeding the purge stream to a power generation unit where the H2 in stream is reacted with O2 to create an exhaust stream; b. concentrating Ar and / or He from the exhaust stream to create a product stream and a tail gas stream.

37. A method for making ammonia, the method comprising: a. mixing H2 with N2 to create a mixed stream; b. de-hydrating the combination of the mixed stream and recycle stream to create a dry stream; c. reacting the H2 and N2 contained in the dry stream in a synthesis reactor to form ammonia (NH3) contained in the effluent stream; d. absorbing NH3 from the effluent stream in water to generate an aqua-ammonia solution and a recycle stream that contains the unreacted H2 and N2; e. separating a fraction of the recycle stream to create a purge stream to control the accumulation of any inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product;g. using the heat generated by the ammonia synthesis reactor to power the dehydration and / or the distillation; h. feeding the purge stream to a power generation unit where the H2 is reacted with O2 to create an exhaust stream; i. concentrating Ar and / or He from the exhaust stream to create a product stream and a tail gas stream.

38. The method of Claim 37, wherein power is generated in fuel cell.

39. The method of Claim 37, wherein power is generated in an internal combustion engine.

40. The method of Claim 37, wherein power is generated in a gas turbine.

41. The method of Claim 37, wherein power is generated in linear generator.

42. The method of Claim 37, wherein power is utilized within the process.

43. The method of Claim 37, wherein heat is recovered from the exhaust stream.

44. The method of Claim 43, wherein the heat is captured in a hot oil, hot water, or steam system.

45. The method of Claim 43, wherein the recovered heat is utilized within the process.

46. The method of Claim 37, wherein water is separated from the exhaust stream prior to concentrating Ar and / or He.

47. The method of Claim 37, wherein Ar and / or He are separated from the exhaust stream via cryogenic distillation.

48. The method of Claim 37, wherein Ar and / or He are separated from the exhaust stream via Pressure Swing Adsorption (PSA).

49. The method of Claim 37, wherein Ar and / or He are separated from the exhaust stream in a selectively permeable membrane.

50. The method of Claim 1, further comprising: a. oxidizing any combination of the aqua-ammonia solution and the concentrated ammonia product to form a NOx stream rich in nitrogen oxides (NOx); b. absorbing NO2 from the NOx stream in water to generate an aqueous solution of nitric acid (HNO3) and a vapor stream.

51. A method for making ammonia, the method comprising: a. mixing H2 with N2 to create a mixed stream; b. de-hydrating the combination of the mixed stream and a recycle stream to create a dry stream; c. reacting the H2 and N2 contained in the dry stream in a synthesis reactor to form an effluent stream comprising ammonia (NH3); d. absorbing NH3 from the effluent stream water to generate an aqua-ammonia solution and a recycle stream that contains the unreacted H2 and N2; e. separating a fraction of the recycle stream to create a purge stream to control the accumulation of any inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product; g. using the heat generated by the ammonia synthesis reactor to power the dehydration and / or the distillation; h. oxidizing any combination of the aqua-ammonia solution and the concentrated ammonia product to form a NOx stream rich in nitrogen oxides (NOx); i. absorbing NO2 from the NOx stream in water to generate an aqueous solution of nitric acid (HNO3) and a vapor stream.

52. The method of Claim 51, wherein oxidation of the NH3 produces heat, which heat is captured in a hot oil, hot water, or steam system.

53. The method of Claim 52, wherein the captured heat is utilized within the process.

54. The method of Claim 51, wherein the NH3 is oxidized with oxygen in the presence of a catalyst.

55. The method of Claim 54, wherein the catalyst comprises a platinum group metal and optionally rhodium.

56. The method of Claim 54, wherein the catalyst comprises cobalt.

57. The method of Claim 51, further comprising cooling the NOx stream while allowing the continuing oxidation of nitrogenous compounds to NO2.

58. The method of Claim 51, further comprising using O2 derived from electrolysis to further oxidize nitrogen oxides such as nitrous oxide (N2O) and nitric oxide (NO) to nitrogen dioxide (NO2).

59. The method of Claim 51, further comprising using O2 derived from electrolysis, ozonating a portion of said O2, and using the partially ozonated stream to further oxidize nitrogen oxides such as nitrous oxide (N2O) and nitric oxide (NO) to nitrogen dioxide (NO2).

60. The method of Claim 51, further comprising using O2 derived from air separation to further oxidize nitrogen oxides such as nitrous oxide (N2O) and nitric oxide (NO) to nitrogen dioxide (NO2).

61. The method of Claim 51, further comprising using O2 derived from air separation, ozonating a portion of said O2, and using the partially ozonated stream to further oxidize nitrogen oxides such as nitrous oxide (N2O) and nitric oxide (NO) to nitrogen dioxide (NO2).

62. The method of Claim 51, wherein the aqueous solution of HNO3 is neutralized with any combinations of stream the aqua-ammonia solution and concentrated ammonia product to form an aqueous solution of ammonium nitrate (NH4NO3).

63. The method of Claim 62, wherein neutralization of the HNO3 produces heat, which heat is captured in a hot oil, hot water, or steam system.

64. The method of Claim 63, wherein the captured heat is utilized within the process.

65. The method of Claim 62, wherein neutralization of the HNO3 produces heat, which heat is utilized to evaporate water contained in the aqueous solution of HNO3.

66. The method of Claim 51, wherein the vapor stream is treated to separate N2 from the other compounds.

67. The method of Claim 66, wherein the separated N2 is recycled to ammonia synthesis.

68. The method of Claim 62, wherein the aqueous solution of ammonium nitrate is further concentrated or diluted by removing or adding water.

69. The method of Claim 62, wherein the aqueous solution of ammonium nitrate is prilled or otherwise converted into solid ammonium nitrate.

70. The method of Claim 68, wherein more concentrated or diluted aqueous solution of ammonium nitrate is prilled or otherwise converted into solid ammonium nitrate.

71. The method of Claim 1, further comprising: a. reacting any combination of the aqua-ammonia product and the concentrated ammonia product with CO2 to form an effluent stream rich in urea (CH4N2O); b. separating an aqueous solution of urea from said effluent stream.

72. A method for making ammonia, the method comprising: a. mixing H2 with N2 to create a mixed stream; b. de-hydrating the combination of the mixed stream and a recycle stream to create a dry stream;c. reacting the H2 and N2 contained in the dry stream in a synthesis reactor to form an effluent stream containing ammonia (NH3); d. absorbing NH3 from the effluent stream in water to generate an aqua-ammonia solution and the recycle stream that contains the unreacted H2 and N2; e. separating a fraction of the recycle stream to create a purge stream to control the accumulation of any inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product; g. using the heat generated by the ammonia synthesis reaction to power the dehydration and / or the distillation; h. reacting any combination of the aqua-ammonia solution and the concentrated ammonia product with CO2 to form an effluent stream rich in urea (CH4N2O); i. separating an aqueous solution of urea from said effluent stream.

73. The method of Claim 72, wherein the CO2 is derived from flue gas.

74. The method of Claim 72, wherein the CO2 is derived from fermentation of biomass or waste products.

75. The method of Claim 72, wherein the CO2 is derived from fermentation of biomass (for example, corn) for the production of ethanol.

76. The method of Claim 72, wherein the CO2 is derived from industrial facilities (for example, natural gas processing).

77. The method of Claim 72, wherein the CO2 is sourced from a pipeline.

78. The method of Claim 72, wherein the CO2 is sourced from Direct Air Capture (DAC).

79. The method of Claim 72, wherein the CO2 has a purity of less than 99% and more than 80%.

80. The method of Claim 72, wherein the urea synthesis is conducted at a pressure above 150 bar.

81. The method of Claim 72, wherein the molar ratio of NH3 and CO2 in the feed streams to the urea synthesis is more than about 2.

82. The method of Claim 72, wherein the aqueous solution of urea is further concentrated in urea by removing water.

83. The method of Claim 82, wherein the concentrated solution of urea is prilled or granulated or otherwise converted into solid urea.

84. The method of Claim 72, wherein the aqueous solution of urea is further diluted in urea by removing water to form Diesel Exhaust Fluid (DEF).

85. The method of Claim 1, further comprising: a. oxidizing a portion of the aqua-ammonia solution and the concentrated ammonia to form a NOx stream rich in nitrogen oxides (NOx); b. absorbing NO2 from the NOx stream in water to generate an aqueous solution of nitric acid (HNO3) and a vapor stream; c. reacting the remaining portion of the aqua-ammonia solution and the concentrated ammonia with CO2 to form a stream rich in urea (CH4N2O); d. separating an aqueous solution of urea from a stream rich in urea; e. combining the aqueous solution of urea with aqueous solution of nitric acid (HNO3) to form urea ammonium nitrate (UAN) solutions.

86. A method for making ammonia, the method comprising: a. mixing H2 with N2 to create a mixed stream; b. de-hydrating the combination of the mixed stream and a recycle stream to create a dry stream; c. reacting the EE and N2 contained in the dry stream in a synthesis reactor to form an effluent stream comprising ammonia (NH3);d. absorbing NH3 from the effluent stream in water to generate an aqua-ammonia solution and the recycle stream that contains the unreacted H2 and N2; e. separating a fraction of the recycle stream to create a purge stream to control the accumulation of any inert species in the system; f. distilling the aqua-ammonia solution to generate a more concentrated ammonia product; g. using the heat generated by the ammonia synthesis reactor to power the dehydration and / or the distillation; h. oxidizing a portion of the aqua-ammonia solution and the concentrated ammonia to form a NOx stream rich in nitrogen oxides (NOx); i. absorbing NO2 from the NOx stream in water to generate an aqueous solution of nitric acid (HNO3) and a vapor stream; j . reacting the remaining portion of streams the aqua-ammonia solution and the concentrated ammonia with CO2 to form an effluent stream rich in urea (CH4N2O); k. separating an aqueous solution of urea from a stream rich in urea; l. combining the aqueous solution of urea with aqueous solution of nitric acid (HNO3) to form urea ammonium nitrate (UAN) solutions87. A system configured to perform any of the methods of any of the preceding claims.

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