Ammonia synthesis method and apparatus

Abstract

A system and method for the synthesis of ammonia are provided. Ammonia is synthesized in two steps using a bifunctional material in a chemical looping reactor. The first step involves fixing nitrogen on the surface of the bifunctional material. In the second step, hydrogen is introduced to the surface of the bifunctional material to react with the lattice nitrogen to produce ammonia. The order of these steps may be reversed. The system may include a control system in communication with the reactor that controls operational parameters associated with the operation of the reactor for ammonia production. The operational parameters may include temperature, pressure, residence time, concentration, and / or humidity. The ammonia may be supplied to various downstream applications or processes, such as, for example, fuel cell systems, refrigeration systems, selective catalytic reduction (SCR) systems, systems for producing chemical feedstocks, systems for producing synthetic fibers, waste treatment systems, water treatment systems, and agricultural applications.

Description

[Technical Field]

[0001] 1. CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application entitled "Methods and Apparatus for Ammonia Synthesis," filed February 7, 2023, and assigned Application No. 63 / 443,876, the entire contents of which are incorporated herein by reference.

[0002] 2. Field of the Invention The invention disclosed herein relates to the production of ammonia, and in particular to a low-cost, two-step process for the efficient synthesis of ammonia. [Background technology]

[0003] 2. Description of Related Art Ammonia (NH3) is a versatile chemical with diverse uses in various industries. Some of its most common uses include agriculture, refrigeration, cleaning, chemical synthesis, pharmaceuticals, and food processing, among others. For example, ammonia is used as a fertilizer in agriculture to provide crops with nitrogen, an essential nutrient for plant growth. Ammonia is used as a refrigerant in large-scale refrigeration systems due to its high thermal efficiency and low global warming potential. Ammonia is used as a cleaning agent due to its ability to dissolve grease and dirt. Ammonia is found in many household and industrial cleaning products. Ammonia is used as a starting material in the production of various chemicals, such as nitric acid, urea, and ammonium nitrate. Ammonia is used as a raw material in the synthesis of various pharmaceuticals, including antihistamines and tranquilizers. Ammonia is used as a sterilant in the food industry to kill bacteria and preserve food. These are just a few of ammonia's many uses, highlighting its importance as a versatile chemical in various industries. The global value of the ammonia industry is estimated to exceed $70 billion.

[0004] Ammonia is synthesized through the Haber-Bosch process, which involves the reaction of nitrogen gas (N2) with hydrogen gas (H2) to form ammonia (NH3). This reaction is typically carried out under conditions of high temperature and pressure, such as approximately 450°C and 200 atmospheres. A catalyst, typically iron or ruthenium, is added to the reaction mixture to increase the reaction rate and ensure completion.

[0005] Ammonia is (R1): N2+ 3H2<=> 2NH3(R1) It has been produced industrially for over a century through the direct combination of N2 and H2 over an iron catalyst using the Haber-Bosch process shown in

[0006] The high temperatures and pressures (T = 450–600 °C, P = 10–25 MPa) associated with the Haber-Bosch process are necessary to activate the stable triple bond of diatomic nitrogen and drive the R equilibrium at an industrially desirable rate. However, these harsh conditions result in a low equilibrium concentration of ammonia due to the thermodynamically favored reverse reaction at temperatures above 300 °C. In fact, unreacted reactants are recycled to the reactor feed at a high rate, achieving H conversion rates of up to 27% in the Haber-Bosch process. Modern ammonia production plants synthesize ammonia via R using N from the atmosphere and H derived from steam reforming (SMR) of methane in natural gas. Due to the high demand for ammonia, the Haber-Bosch process consumes 2% of the world's annual natural gas supply to produce H for the process. To meet demand, ammonia production plants are often located near large natural gas reserves, resulting in large-scale industrial centralization. The process itself consumes significant amounts of energy, an estimated 1-2% of global annual demand, primarily to produce hydrogen via steam methane reforming (SMR). In addition to its high energy requirements, the Haber-Bosch process also has significant environmental impacts, producing CO2 as a by-product of SMR. The Haber-Bosch process is responsible for 1.6% of global annual anthropogenic CO2 emissions, making it the most carbon-intensive chemical production process. Summary of the Invention [Problem to be solved by the invention]

[0007] What is needed are more efficient methods and apparatus for producing ammonia than those currently available. The technology would preferably result in significant reductions in energy consumption and capital costs for producers, and enable applications that were previously unfeasible due to expense. For example, the technology should provide for the availability of ammonia for small-scale energy storage applications for renewable energy projects, on-site fertilizer production for farmers, and on-site chemical production in the pharmaceutical industry. [Means for solving the problem]

[0008] A system and method for the synthesis of ammonia is disclosed. In one embodiment, ammonia is synthesized in two steps using a bifunctional material in a chemical loop reactor at atmospheric pressure. The first step involves fixing nitrogen to the surface of the bifunctional material. In the second step, hydrogen is introduced to the surface of the bifunctional material to react with the lattice nitrogen to produce ammonia. The order of these steps may be reversed.

[0009] In one embodiment, the two-step reaction can be controlled by switching gas flows in a fixed bed reactor to allow independent control of the temperature in each step, thereby enabling cyclic synthesis of ammonia at low pressure.

[0010] In one embodiment, the bifunctional material that functions as the N2 / H2 carrier is an alloy of lanthanum-nickel (LaNi5), which has been shown to synthesize ammonia at atmospheric pressure with reasonable yields. The formation of the nitride intermediate using the LaNi5 alloy can be carried out in a nitrogen atmosphere. The subsequent Ni x N y Hydrogenation of the N- or N-polymer is thermodynamically favorable.

[0011] In one embodiment, a system for producing ammonia is provided, comprising: (i) a reactor having an inlet, an outlet, and a reactor region; and (ii) a bifunctional material within the reactor region, the bifunctional material configured to fix nitrogen on its surface when exposed to a nitrogen-containing gas and to result in the production of ammonia when exposed to a hydrogen-containing gas. The ammonia synthesis can occur at temperatures up to 300 degrees Celsius. The ammonia synthesis can occur at atmospheric pressure.

[0012] In one embodiment, the bifunctional material is LaNi5, LaNi 4.8 Sn 0.2, NiBaH2, Ni4W, TiMox[x=1-3], ZrMnx[x=1-3], Ni3Ga, MnNi3, Ni3Ge, Ce2MnN3, ZrCr, ZrCr2, Ni2Mo3N, LaCoSi, LaRuSi, Cs-Ru / MgO, Co2Mo3N, or a combination thereof.

[0013] In one embodiment, an ammonia synthesis promoter may be provided in the reactor region, and the ammonia synthesis promoter may be sodium (Na), calcium (Ca), potassium (K), barium (Ba), ruthenium (Ru), or a combination thereof.

[0014] In one embodiment, a support material may be provided within the reactor region, and the support material may be aluminum, lanthanum, magnesium, cerium oxide, or a combination thereof.

[0015] The system may include a control system. The control system may be in communication with the reactor. In one embodiment, the control system may include machine-readable instructions for controlling operational parameters associated with operation of the reactor for producing ammonia. The operational parameters may include temperature, pressure, residence time, concentration, humidity, and combinations thereof.

[0016] In one embodiment, a computer program product may be stored on a non-transitory machine-readable medium and may include machine-readable instructions for (i) controlling the production of ammonia by operating a reactor comprising an inlet, an outlet, and a reactor region, and (ii) a bifunctional material within the reactor region, the bifunctional material configured to fix nitrogen on its surface when exposed to a nitrogen-containing gas and to result in the production of ammonia when exposed to a hydrogen-containing gas.

[0017] In one embodiment, the computer program product can control the production of ammonia by communication over a network including a controller having computing power, one or more sensors, a power source, one or more electrically operated valves, one or more switches, an interface, and combinations thereof.

[0018] In one embodiment, the control by the computer program product includes instructions for switching between gas supplies. In one embodiment, the control by the computer program product includes instructions for monitoring the production of ammonia. In one embodiment, the control by the computer program product includes instructions for operating a separator to recycle at least a portion of the unreacted nitrogen-containing gas and the unreacted hydrogen-containing gas. In one embodiment, the control by the computer program product includes instructions for maintaining a temperature of the reactor below a temperature of at least one of nitridation and ammonia decomposition.

[0019] In one embodiment, a system for producing ammonia includes: (i) a reactor having an inlet, an outlet, and a reactor region; (ii) a bifunctional material within the reactor region, the bifunctional material configured to fix nitrogen on its surface when exposed to a nitrogen-containing gas and to result in the production of ammonia when exposed to a hydrogen-containing gas; and (iii) a computer program product stored on a non-transitory machine-readable medium, the computer program product including machine-readable instructions for managing the operation of the reactor and thereby controlling production.

[0020] In one embodiment, the ammonia produced by ammonia synthesis may be used in downstream applications such as, for example, fuel cell systems, refrigeration systems, selective catalytic reduction (SCR) systems, systems for the production of chemical feedstocks, systems for the production of synthetic fibers, waste treatment systems, water treatment systems, or agricultural applications.

[0021] In one embodiment, the system for ammonia synthesis may be configured as one of a fixed, mobile, temporary or permanent installation.

[0022] In one embodiment, a method for producing ammonia includes (i) introducing into a reactor a bifunctional material configured to fix nitrogen on its surface when exposed to a nitrogen-containing gas and to result in the production of ammonia when exposed to a hydrogen-containing gas; (ii) introducing nitrogen into the reactor, thereby fixing nitrogen to the bifunctional material; (iii) terminating the introduction of nitrogen into the reactor; and (iv) introducing hydrogen into the reactor, thereby producing ammonia through the reaction of hydrogen and nitrogen.

[0023] In one embodiment, the order of hydrogen and nitrogen introduction is reversed.

[0024] In one embodiment, the reactor operates at a first temperature when nitrogen is introduced into the reactor, and the reactor operates at a second temperature when hydrogen is introduced into the reactor. In one embodiment, the first temperature is the same as the second temperature. In one embodiment, the first temperature is higher than the second temperature.

[0025] In one embodiment, the first temperature may be between 200° C. and 900° C. In one embodiment, the second temperature is between 100° C. and 400° C. In one embodiment, the nitrogen production is carried out under isobaric conditions.

[0026] In one embodiment, a control system is in communication with the reactor and controls one or more operational parameters associated with the operation of the reactor for ammonia production. The one or more operational parameters may include temperature, pressure, residence time, concentration, and humidity. The ammonia produced by ammonia synthesis may be used in fuel cell systems, refrigeration systems, selective catalytic reduction (SCR) systems, systems for producing chemical feedstocks, systems for producing synthetic fibers, waste treatment systems, water treatment systems, agricultural applications, or other downstream applications.

[0027] Additional features, functions, and advantages of the systems and methods of the present disclosure will become apparent from the following description, particularly when read in conjunction with the accompanying figures.

[0028] The features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0029] [Figure 1] Figure 1A is a schematic diagram of a reactor system. Figure 1B is a schematic diagram of the reactor system of Figure 1A operating for nitrogen fixation (Figure 1B) and ammonia production (Figure 1C) as part of chemical looping synthesis. Figure 1C is a schematic diagram of the reactor system of Figure 1A operating for nitrogen fixation (Figure 1B) and ammonia production (Figure 1C) as part of chemical looping synthesis. [Figure 2] 1 is a graph of an X-ray diffraction (XRD) profile. [Figure 3A] 3A and 3B are images of LaNi5 alloy particles and pores, respectively, captured by scanning electron microscope (SEM). [Figure 3B] 3A and 3B are images of LaNi5 alloy particles and pores, respectively, captured by scanning electron microscope (SEM). [Figure 4A] 4A is a graph showing the scanned area of ​​a LaNi5 alloy (FIG. 4A) and the energy dispersive X-ray (EDX) profile and elemental analysis of the LaNi5 alloy (FIG. 4B). [Figure 4B] 4A is a graph showing the scanned area of ​​a LaNi5 alloy (FIG. 4A) and the energy dispersive X-ray (EDX) profile and elemental analysis of the LaNi5 alloy (FIG. 4B). [Figure 5] FIG. 1 depicts a schematic system for ammonia production and associated thermogravimetric analysis. [Figure 6] 1 is a graph showing the temperature and weight changes of a LaNi5 sample during synthesis in a nitrogen atmosphere. [Figure 7A] 7A and 7B are graphs showing XRD profiles of LaNi5 alloy before (FIG. 7A) and after (FIG. 7B) synthesis. [Figure 7B] 7A and 7B are graphs showing XRD profiles of LaNi5 alloy before (FIG. 7A) and after (FIG. 7B) synthesis. [Figure 8A] 8A and 8B are SEM images of the LaNi5 alloy surface before (FIG. 8A) and after (FIG. 8B) synthesis. [Figure 8B]8A and 8B are SEM images of the LaNi5 alloy surface before (FIG. 8A) and after (FIG. 8B) synthesis. [Figure 9A] Scanned area of ​​LaNi5 alloy (FIG. 9A), and EDX profile and elemental analysis of LaNi5 alloy after synthesis in nitrogen atmosphere (FIG. 9B). [Figure 9B] Scanned area of ​​LaNi5 alloy (FIG. 9A), and EDX profile and elemental analysis of LaNi5 alloy after synthesis in nitrogen atmosphere (FIG. 9B). [Figure 10A] FIG. 1 depicts a schematic system for ammonia production and associated thermogravimetric analysis. [Figure 10B] FIG. 10B is a diagram showing an experimental system configured according to the schematic system shown in FIG. 10A. [Figure 11A] 11A and 11B are graphs depicting the reactor operating conditions during a reduction step with hydrogen gas introduction (FIG. 11A) and in a chemical loop where nitrogen, hydrogen, and argon are circulating at a constant temperature of 270° C. (FIG. 11B). [Figure 11B] 11A and 11B are graphs depicting the reactor operating conditions during a reduction step with hydrogen gas introduction (FIG. 11A) and in a chemical loop where nitrogen, hydrogen, and argon are circulating at a constant temperature of 270° C. (FIG. 11B). [Figure 12] 1 is a graph depicting the composition at the reactor outlet during isothermal operation of chemical looping ammonia synthesis. [Figure 13] 1 is a graph showing reactor operating conditions during high temperature operation of chemical looping ammonia synthesis. [Figure 14] 1 is a graph showing the composition at the reactor outlet during high temperature operation of chemical looping ammonia synthesis. [Figure 15] 1 is a flow chart illustrating a control system associated with ammonia synthesis. [Figure 16] FIG. 1 is a block diagram of a system for controlling ammonia synthesis. [Figure 17] FIG. 1 is a block diagram of a computing device implementing a control system for ammonia synthesis. [Figure 18]FIG. 1 is a block diagram of a system for an ammonia synthesis detection environment. DETAILED DESCRIPTION OF THE INVENTION

[0030] Disclosed herein are methods and apparatus for producing ammonia. Generally, the disclosed methods and apparatus provide for ammonia production at atmospheric pressure using a bifunctional substrate material in a chemical looping reactor. Using the techniques disclosed herein, ammonia can be synthesized in two steps. The first step involves fixing nitrogen to the surface of the material. In the second step, hydrogen is introduced to the surface of the material to react with the lattice nitrogen to produce ammonia. The order of these steps may be reversed, and additional embodiments may be implemented. Indeed, the reaction can be controlled by switching gas flows to the reactor and independently controlling the temperature in the reactor, allowing for the synthesis of ammonia at low pressures.

[0031] Although the embodiments disclosed herein relate to lanthanum-nickel alloys (particularly LaNi5), other materials may be suitable for use in the disclosed ammonia synthesis process. Additional examples of bifunctional materials that can be utilized to synthesize ammonia via a chemical looping process include NiBaH2, Ni4W, TiMo x [x=1~3], ZrMn x [x=1-3], Ni3Ga, MnNi3, Ni3Ge, Ce2MnN3, ZrCr, ZrCr2, Ni2Mo3N, LaCoSi, LaRuSi, Cs-Ru / MgO, Co2Mo3N, as well as various combinations of the aforementioned. These materials are thermodynamically favorable for NH3 synthesis through chemical looping processes.

[0032] The bifunctional material can be configured to effectively promote ammonia synthesis. For example, the bifunctional material can be pre-treated and / or introduced into the reactor, e.g., through effective dispersion of the bifunctional material within the reactor, such that the surface area of ​​the bifunctional material available for nitridation and hydrogenation is maintained and / or maximized.

[0033] In an exemplary embodiment, a chemical looping reactor using a gas switching approach and a nitrogen carrier for producing ammonia is disclosed. In the embodiment disclosed herein, a lanthanum-nickel alloy, LaNi5, is included in the two-step reaction and serves as the nitrogen carrier for ammonia production. Alternative bifunctional materials may be utilized in the two-step process. The use of a gas switching approach in combination with the alloy carrier allows for the production of ammonia at moderate temperatures and low pressures (e.g., atmospheric pressure). Additionally, the use of the alloy as a nitrogen carrier allows for the incorporation of elemental materials that promote ammonia production, hydrogen fixation, and / or nitrogen fixation, further enhancing reactor performance.

[0034] Referring to FIG. 1A, aspects of one embodiment of a suitable reactor are shown schematically. Generally, this reactor configuration provides a two-step process for producing ammonia using an alloy of LaNi5. The LaNi5 alloy is used to exploit the synergistic effects of combining two ammonia-promoting elements (La and Ni) into one bifunctional material. The reactor configuration shown in FIG. 1A is a fixed-bed reactor containing the LaNi5 alloy. Inlet gas flow to the reactor is controlled by a three-way valve, allowing for rapid gas switching to operate through Step 1 (FIG. 1B; nitrogen fixation) and Step 2 (FIG. 1C; ammonia production).

[0035] In the first step of the process (FIG. 1B), nitrogen is introduced into the reactor and fixed to the surface of the bifunctional material, LaNi5 alloy, through the proposed R2 and R3 mechanisms: 6Ni + N2<-> 2Ni3N (R2) 2La + N2<-> 2LaN (R3) As is apparent, both the lanthanum and nickel associated with the LaNi5 alloy provide the nitrogen fixation functionality.

[0036] In the second step of the process, the nitrogen supply to the reactor is stopped and hydrogen is introduced into the reactor by operating the three-way valve. The hydrogen then reacts with the nitrogen on the surface of the bifunctional material to produce ammonia through mechanisms R4 and R5 presented below. 2Ni3N + 3H2<-> 6Ni + 2NH3(R4) 2LaN + 3H2<-> 2La + 2NH3(R5)

[0037] As can be seen, in step 2 of the two-step process, hydrogen reacts with nitrogen fixed to both the lanthanum and nickel bound to the bifunctional LaNi5 alloy to form ammonia.

[0038] The disclosed chemical looping ammonia synthesis enables efficient ammonia production at atmospheric pressure and mild temperatures (<300°C). By avoiding the equilibrium constraints of the conventional Haber-Bosch process, chemical looping ammonia synthesis enables ammonia production at reduced pressures and temperatures, and by allowing the use of less expensive equipment than the compressors and reactors required in the Haber-Bosch process, it can significantly reduce both capital and operating costs. Furthermore, chemical looping ammonia synthesis is particularly suited to green ammonia production due to the production of nitrogen and hydrogen in separate streams, a feature of chemical looping ammonia synthesis reactors.

[0039] The disclosed chemical looping ammonia synthesis systems can vary in the number of steps, support material, operating temperature, and hydrogen source, and can utilize established technology / equipment, such as compressors, heaters, heat exchangers, and fixed-bed reactors.

[0040] Each step associated with the two-step process (i.e., nitrogen fixation and ammonia production) is operated for a suitable duration. In one embodiment, the nitrogen fixation step is operated until further nitrogen fixation by the bifunctional material is reduced (e.g., as determined by monitoring gas flow from the reactor), and the ammonia production step is operated until further ammonia production is reduced (e.g., as determined by monitoring gas flow from the reactor). In one embodiment, the durations of steps 1 and 2 can be determined based on experimental results and / or empirical calculations. After step 2 is completed, step 1 can be started again.

[0041] The two-step ammonia synthesis technology was experimentally tested using LaNi5 alloy. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed on the alloy to confirm its composition and purity. The ability of the alloy to fix nitrogen in chemical looping step 1 was determined via thermogravimetric analysis (TGA) in a nitrogen atmosphere. A laboratory-scale reactor was used to determine the ability of LaNi5 alloy to synthesize ammonia in chemical looping. The reactor outlet gas was analyzed using gas chromatography (GC) to detect the presence of ammonia.

[0042] Qualitative testing of the alloy was performed. The LaNi5 alloy sample used in the experiments was purchased from ThermoFisher Scientific Chemical Inc., with a nominal purity of 99.9% LaNi5 based on rare earth oxides (REOs). To confirm the alloy composition, the sample was analyzed using X-ray diffraction (XRD). The XRD device used was a Bruker D8 Advance high-temperature X-ray diffractometer. The device was operated at 25°C with a 1 mm slit at angles of 8 to 140°. The XRD profile of the sample was compared with the International Center for Diffraction Data (ICDD) database and is shown in Figure 2. Figure 2 shows that the XRD profile of the LaNi5 sample was compared with the LaNi 4.8 Sn 0.2 It is shown that it is in good agreement with

[0043] At the time of analysis, the database did not contain the LaNi5 alloy, so LaNi 4.8 Sn 0.2 showed the closest elemental match in the database. The La XRD peak was most prominent as a prominent peak at 42°C, with three peak clusters seen near 57-64°C. Ni XRD peaks were seen at peaks 30, 45, and 75°C. Additionally, the sample's XRD pattern was compared to the XRD pattern for LaNi5 in the literature and showed reasonable agreement. Comparison of the sample's XRD profile with third-party data confirmed the test material was LaNi5 with minimal impurities.

[0044] The surface topology of the alloy was determined by scanning electron microscopy (SEM) using a fresh sample of LaNi5. The SEM used was an FEI Quanta 250 FEG field emission scanning electron microscope (ESEM) operated at 25°C in partial vacuum. The SEM image shown in Figure 3A shows irregularities in the shape and size of the alloy particles. Figure 3B also shows that some particles of the alloy may have pores of significant size. In this case, the pores were observed to be approximately 3.654 μm × 4.707 μm. As a result of the porosity and irregular shape of the particles, there is a greater opportunity for reactant gases to come into contact with the alloy, thus improving reaction efficiency. In some embodiments, synthetic bifunctional materials with higher levels of surface area and mass transport properties can be synthesized to better support the two-step ammonia synthesis reaction and related processes. The alloy composition is also not limiting. As noted above, other bifunctional materials can be utilized to facilitate the two-step ammonia synthesis reaction and process function.

[0045] The LaNi5 alloy was investigated using energy dispersive X-ray (EDX) to determine the elements present on its surface and their distribution. A scan area was defined and analyzed on the surface of the alloy, as shown in FIG. 4A. The EDX profile, shown in FIG. 4B, identified the presence of La and Ni in the alloy at 16.4% and 71% atomic composition, respectively. The distribution of La and Ni was consistent with the expected distribution for a LaNi5 alloy with minimal impurities. A series of analyses performed on the as-received LaNi5 sample indicate that the alloy was provided with minimal impurities and possesses characteristics particularly suitable for gas-solid reactions.

[0046] The nitrogen fixation functionality of the LaNi5 alloy was evaluated by placing 200 mg of the LaNi5 alloy in a Shimadzu TGA using a nitrogen atmosphere. The TGA experimental setup is shown in Figure 5. The temperature was programmed to increase from 25 °C to 400 °C at a heating rate of 25 °C / min. Nitrogen was passed over the sample at a rate of 20 ml / min for the duration of the test. The weight change of the sample was measured using a suspended balance in the TGA. As shown in Figure 5, cylinders 1 and 2 contain nitrogen and hydrogen, respectively. Component 3 is the gas flow controller, component 4 is the Shimadzu TGA, component 5 is the TGA furnace, and region 6 is the purge gas outlet. Component 7 is a computer used for data acquisition and experimental control / programming.

[0047] The test samples were analyzed to determine whether any compositional changes occurred at the alloy surface. The test samples were analyzed using XRD, SEM, and EDX following the same procedures used for fresh samples. The temperature and weight changes of the samples during the TGA experiment in a nitrogen atmosphere are shown in Figure 6. The XRD profiles of the alloy before and after the TGA experiment are shown in Figures 7A and 7B.

[0048] Figure 7A shows a notable change in the number of peaks after the TGA experiment. Nickel was identified as the only element detected in the sample by the ICDD database, while other peaks were not identified. The peaks at 30, 45, and 75 °C attributed to nickel remained unchanged after the experiment, while the peaks attributed to lanthanum disappeared or shifted. This suggests that lanthanum may play an important role in nitrogen fixation, forming lanthanum nitride (LaN). Notably, the peaks at 35, 42, 43, 57, and 68 °C were no longer present in the sample after the experiment. In addition, the presence of a newly observed peak at 53 °C provides further evidence that a compositional change occurred on the surface of the LaNi5 alloy.

[0049] The post-experiment sample was then analyzed using SEM and compared to a fresh sample in Figures 8A and 8B. After the TGA experiment, the SEM image shows more precipitates on the surface of the material than before the experiment. Analysis of these precipitates using EDX is shown in Figures 9A and 9B and confirms that they are precipitates of elemental nitrogen, carbon, and oxygen. Approximately 0.04 wt.% (0.08 mg) of the post-experiment sample was identified as elemental nitrogen. This represents a 0.002% conversion rate in nitrogen, demonstrating the alloy's nitrogen fixation capability at low pressures and mild temperatures. Figure 9A shows the scanned area, and Figure 9B shows the EDX profile and elemental analysis of the alloy after the TGA experiment in a nitrogen atmosphere.

[0050] An example of a chemical looping ammonia synthesis system for use in the two-step synthesis of ammonia is shown schematically in Figure 10A. As shown in Figure 10A, reference numerals 1, 2, and 3 are gas cylinders of H, N, and Ar, component 4 is a gas manifold and flow meter, component 5 is an Altimara BenchCat shown on the right, component 6 is an Agilent MicroGC 3000, component 7 is a purge line, and component 8 is a computer for data acquisition and analysis.

[0051] The experimental setup, according to the schematic diagram in Figure 10A, is shown in Figure 10B. This experimental setup was used to determine the performance of the LaNi5 alloy in a chemical loop for ammonia synthesis. Hydrogen, nitrogen, and argon gas cylinders were supplied by Airgas at the following concentrations: hydrogen (3%) in argon (97%), nitrogen 99.99%, and argon 99.99%. An Altimara Bench-Cat system was used to control the flow rate of the feed gases to the reactor and the reactor temperature. The experiment was carried out in a U-tube connected to the Altimara Bench-Cat system, and the outlet was directed into an Agilent MicroGC 3000 unit for analysis, as shown. The data was logged on the computer using Agilent Gas Analyzer software.

[0052] A LaNi5 chemical loop for ammonia synthesis was demonstrated in two experiments. In the first experiment, the chemical loop was run under isothermal and isobaric conditions at 270°C and 0.207 MPa, respectively. In the second experiment, the first step of the chemical loop was operated at 500°C and the second step at 400°C. The second experiment was also operated under isobaric conditions at 0.207 MPa.

[0053] Experiment 1: Isothermal operation of a chemical loop The experiment began by reducing 2 grams of LaNi5 in a hydrogen atmosphere at 600°C for 1 hour in a bench-top reactor. The bench-top reactor used was an Altimara BenchCAT system available from Altimara Instruments, Cummings, Georgia. Reduction of the alloy was necessary to remove surface contaminants from the sample and activate the material for testing. Results of the reduction process from the Altimara Bench-Cat system are shown in Figure 11A, which shows that the H2 flow rate to the U-tube reactor was maintained and the reduction temperature of 600°C was maintained.

[0054] Immediately after the reduction step, the chemical loop procedure shown in Figure 11B was initiated. This procedure began with nitrogen fixation for 1 hour at a flow rate of 30 ml / min. After the nitrogen fixation step, argon was introduced into the reactor at 25 ml / min for 5 minutes to purge residual nitrogen from the reactor. Hydrogen was then introduced into the reactor at a flow rate of 30 ml / min for 1 hour. At the end of the hydrogen step, argon was used to purge the reactor at a flow rate of 25 ml / min for 5 minutes. This process was repeated once more for the entire cycle. The operating conditions of the reactor for the reduction step (Figure 11A) and the reactor in the chemical loop in which nitrogen, hydrogen, and argon were circulated at a constant temperature of 270 °C (Figure 11B) are as shown.

[0055] The gas composition exiting the reactor was analyzed, and its changes were observed over time. As shown in Figure 12, during the nitrogen fixation step, only nitrogen was present in the reactor. In the ammonia production step, 3% hydrogen was fed to the reactor, resulting in a peak in the ammonia composition, which declined over the course of the reaction step. It is noteworthy that the hydrogen peak did not appear until approximately 10 minutes into the reaction cycle. This suggests that hydrogen was consumed by reaction with nitrogen on the alloy surface during this period. In addition, as the hydrogen concentration at the reactor outlet increased, the ammonia concentration decreased. This further suggests that hydrogen in the reactor reacted with nitrogen on the material surface until the surface nitrogen was depleted. Next, the reactor vessel was purged with argon, and nitrogen fixation was performed again. Next, in the second ammonia production step in Figure 12, hydrogen was reintroduced into the reactor, causing the ammonia peak to reappear. During the reaction step, the hydrogen peak did not appear until approximately 10 minutes into the reaction. FIG. 12 represents the composition at the reactor outlet during isothermal operation of the chemical loop.

[0056] Experiment 2: High temperature operation of the chemical loop reactor In this experiment, a fresh sample of LaNi5 alloy was reduced at 600°C, followed by nitrogen fixation at 500°C and ammonia production at 400°C. The operating conditions for this experiment are shown in Figure 13, and the gas composition exiting the reactor is shown in Figure 14. Figure 14 shows ammonia production immediately after hydrogen was introduced into the reactor. The ammonia composition peaked approximately 30 minutes after the start of the ammonia production process and then gradually decreased until the end of the process. After approximately 15 minutes of operation, hydrogen appeared at the reactor outlet, consistent with observations during isothermal operation of the chemical loop (Experiment 1). This result further demonstrates that hydrogen was consumed during this process and ammonia was produced. After 40 minutes of operation, no ammonia was present at the reactor outlet.

[0057] As demonstrated in the previous experiments, LaNi5 alloy was shown to be effective for nitrogen fixation at atmospheric pressure, with a conversion rate of 0.002 wt.%, as indicated by TGA testing. LaNi5 alloy was used to synthesize ammonia in a chemical loop in both low-temperature isothermal experiments and high-temperature experiments. In both experiments, the presence of ammonia was confirmed using gas chromatography on the reactor outlet gas. Thus, this experiment demonstrates the synthesis of ammonia under atmospheric conditions using a LaNi5 alloy chemical loop at moderate temperatures.

[0058] Aspects of the exemplary embodiment are disclosed, and several additional features and advantages are set forth herein.

[0059] In some embodiments, a system for the synthesis of ammonia includes a chemical loop reactor using a gas switching technique and a nitrogen carrier that produces ammonia when introduced, and further includes a control system. Figure 15 provides a flowchart of functionalities that may be included in a control system for the synthesis of ammonia. The control system may include components such as a controller with computing capabilities, sensors (e.g., for sensing temperature, pressure, flow, humidity, and other parameters), at least one power supply, electrically operated valves, switches, a network (e.g., for communication between the controller and sensors, switches, valves, or other components of the control system), and an interface (e.g., visual and / or audio components, keyboard, pointing device, etc.) for communication with a user and / or external systems. The computer processing system may include a data storage device. The data storage device may be configured with non-transitory machine-readable media useful for maintaining machine-readable instructions suitable for operating the system for the synthesis of ammonia. The machine-readable instructions, which may be generally referred to as "software," may be configured for a variety of operating conditions, system designs, inputs, outputs, etc. Non-limiting examples include control of temperature, pressure, residence time, concentration, humidity, and other parameters. Control may include real-time or near real-time monitoring and adjustment. The software may further be configured to provide the operator with production-related data, such as conversion rates, consumption rates, output, energy demand, and other similar parameters of interest.

[0060] The disclosed technology provides for the synthesis of ammonia over a wide range of temperatures. Generally, the temperature range suitable for synthesis is limited by the decomposition temperature, thermodynamics, and kinetics of ammonia. Exemplary temperature ranges include lower temperatures, e.g., as low as 270°C, and higher temperatures, e.g., as high as 400°C.

[0061] In one embodiment, the synthesis loop can be fed at a preset flow rate, e.g., 2600 kmol / h, and the ratio of nitrogen to hydrogen in the two steps can be operated at a preset ratio, e.g., 3:1 nitrogen to hydrogen.

[0062] In one embodiment, the chemical loop reactor operates in a cyclic steady state using an adiabatic reactor. The feed gas is heated to the setpoint temperature of the chemical loop before reacting. Ammonia is separated from the reactor outlet using a separator, and unreacted gas is recycled back to the reactor using a compressor.

[0063] In one embodiment, a multi-reactor assembly is formed of chemical loop reactors connected in series. The feed gas can be preheated in a heat exchanger before being fed to a heater, which is set to a predetermined temperature (set point) before being introduced into the chemical loop reactors in the multi-reactor assembly. Ammonia is separated from the reactor outlet, and unreacted N2 and H2 are recycled to form the synthesis loop.

[0064] Materials other than or in addition to LaNi5 may be suitable for use as substrate materials. In general, preferred embodiments of substrate materials include bifunctional materials. Materials other than or in addition to LaNi5 may be suitable for use as substrate materials, such as, for example, NiBaH2.

[0065] In one embodiment, the LaNi5 sample was exposed to nitrogen at 400° C. for 1 hour. In an alternative embodiment, the LaNi5 sample was operated in an N2-H2 chemical loop at 400° C. In a further embodiment, the LaNi5 sample was operated in an N2-H2 chemical loop where nitridation occurred at 400° C. and hydrogenation occurred at 250° C.

[0066] It has been found that hydrogenation at lower temperatures compared to the nitriding temperature, for example, hydrogenation at 250°C compared to nitridation at 400°C, reduces more nitride and avoids the ammonia decomposition that can occur at higher temperatures.

[0067] In one embodiment, a ball-milled LaNi5 alloy sample was reacted in a fixed-bed reactor at 250°C for four chemical looping cycles. The NH3 partial pressure steadily increased with each step of the chemical loop. The H2 partial pressure decreased with each cycle, suggesting that H2 was consumed to produce NH3 and / or was immobilized on the surface of the LaNi5 material. In the second N2 cycle, the N2 partial pressure decreased significantly, and an increase in the NH3 partial pressure was observed. This result suggests that there was enough H2 on the LaNi5 material to form NH3.

[0068] In one embodiment, one or more ammonia synthesis promoters, including sodium (Na), calcium (Ca), potassium (K), barium (Ba), ruthenium (Ru), and combinations thereof, may be included in the chemical looping reactor. The promoters may help enhance the activity of the bifunctional material in ammonia synthesis. Potential promoters can be classified into structural and electronic promoters. The use of alkali metal, alkaline earth metal, and rare earth metal materials as promoters for catalysts used in ammonia synthesis is known. Alkali metals are also recognized for their ability to improve the activity, selectivity, and stability of heterogeneous catalysts in chemical processes. Electron donation by alkali metals may facilitate N2 adsorption by promoting the donation of electron density to the antibonding orbital of N2.

[0069] In one embodiment, one or more support materials may be included in the chemical looping reactor. The support materials may function to improve potential gas-solid interactions by reducing or preventing the bifunctional particles from clumping together (agglomeration) and increasing the surface area available for nitridation and / or hydrogenation. Exemplary supports include aluminum, lanthanum, magnesium, cerium oxide, and combinations thereof. These materials may provide ancillary benefits to ammonia synthesis in that they are commonly used in ammonia synthesis catalysts.

[0070] The disclosed technology offers several advantages over prior art processes. First, by operating at lower pressures and temperatures, a reduction in the energy consumption required to produce ammonia is realized. The reduced pressure leads to a significant reduction in capital costs for the reactor and associated auxiliary equipment. The milder operating conditions of the reactor provide improved safety over prior art processes, reducing the likelihood of production instability. Prior art processes are known to be unstable due to the requirements of the operating conditions and reaction mechanism. The technology disclosed herein offers lower energy usage, improved stability, increased safety, and cost savings.

[0071] The ammonia synthesis loop was modeled using process simulation software designed for use in the chemical industry (ASPEN PLUS, available from Aspen Tech, Bedford, Massachusetts). The modeling found that chemical looping synthesis of ammonia using bifunctional materials reduces synthesis costs by 90% compared to the Haber-Bosch process at a comparable scale when the chemical looping synthesis is operated at low temperatures (e.g., below 300°C).

[0072] Chemical looping technology for ammonia synthesis represents an opportunity for production in previously unavailable environments and at previously unachieved reduced costs. As a result, this technology provides a way to utilize ammonia for many industrial, commercial, and residential purposes where such methods have not previously been practical.

[0073] For example, the technology disclosed herein enables a new generation of ammonia production systems that can be scaled according to the specific application. Examples of applications that could benefit from a production system that produces low-cost ammonia include fuel cells; refrigeration systems; selective catalytic reduction (SCR) systems, e.g., NO XUses include those for emission reduction; as a chemical feedstock for building many other chemicals, including nitric acid, amines, and urea; and in the textile industry for the production of synthetic fibers such as nylon, as well as for dyeing and processing. Cheaper ammonia can reduce costs in textile manufacturing, waste disposal and water treatment, and agricultural applications such as pest control and soil and water pH adjustment. In some of these embodiments, the manufacturing system can be configured to be built into the intended application and thus integrated into the manufacturing system.

[0074] As can be imagined, facilities for the production of ammonia may be fixed, mobile, temporary, permanent, or configured in any other manner, on a scale that may be deemed appropriate by the user or operator.

[0075] 16-18 , control system 100 includes a central computer processing system 126 that communicates with each of user devices 106 and / or imaging devices 104 and one or more databases 108 associated with system 100 through a communication interface 128. Communication interface 128 is configured to provide a communication network between components of system 100, allowing data to be electronically transmitted and / or received by the components of system 100. System 100 may include at least one processing device 130 having a processor 132 for receiving and processing data stored in system 100. System 100 may include at least one user interface 134. In some embodiments, user interface 134 may include a display in the form of a graphical user interface (GUI) 136. GUI 136 may be a display integrated into user device 106 and / or imaging device 104, allowing users to communicate with each other and / or with system 100 via communication interface 128. System 100 includes a detection module 138 for processing sensed operational parameters / data in connection with the two-step process for ammonia synthesis in a reactor. Detection module 138 is executed by processing device 130 and can implement model 112 and analyze any images 110 received by system 100. Detection module 138 can execute operational parameter detection model 112 and output results (and possibly predictions) associated with sensed operational parameters (e.g., temperature, pressure, residence time, concentration, and / or humidity). In some embodiments, detection module 138 can include multiple units or modules executable to perform each of the sensing and control steps of system 100 (e.g., control of temperature, pressure, residence time, concentration, and / or humidity, and combinations thereof, associated with the reactor).

[0076] The system 100 for control of ammonia synthesis may include data collection associated with input and output samples 102 associated with ammonia synthesis, an imaging device 104 for acquiring data related to ammonia synthesis, a user / user device 106, a central computer processing system 126, a communication interface 128, a detection module 138 for operating parameters, a processing device 130 having a processor 132, a user interface 134 having a graphical user interface 136, and a database 108. The database 108 may include an operating parameter detection module 112, process guidelines 116, historical process data 118, input images 110, feedstock data 120, reports 124, downstream usage data 122, and a neural network 114.

[0077] 17 is a block diagram of a computing device 200 according to an embodiment. The computing device 200 includes one or more non-transitory computer-readable media for storing one or more computer-executable instructions or software for implementing exemplary embodiments. The non-transitory computer-readable media may include, but are not limited to, one or more types of hardware memory, non-transitory tangible media (e.g., one or more magnetic storage disks, one or more optical disks, one or more flash drives), etc. For example, the memory 206 included in the computing device 200 may store computer-readable and computer-executable instructions or software for implementing exemplary embodiments of the present disclosure (e.g., instructions for operating a two-stage ammonia synthesis reactor, instructions for operating an ammonia synthesis detection model, instructions for operating a processing device, instructions for operating a communication interface, instructions for operating a user interface, instructions for operating a central computing system, and combinations thereof). Computing device 200 also includes a configurable and / or programmable processor 202 and associated core 204, and possibly one or more additional configurable and / or programmable processors 202′ and associated cores 204′ (e.g., in the case of a computer system having multiple processors / cores), for executing computer-readable and computer-executable instructions or software stored in memory 206 and other programs for controlling the system hardware. Processor 202 and processor 202′ may each be a single-core processor or a multi-core (204 and 204′) processor.

[0078] Virtualization may be utilized in computing device 200 so that infrastructure and resources in computing device 200 can be dynamically shared. Virtual machines 214 may be provided to handle processes running on multiple processors, so that the processes appear to be using only one computing resource rather than multiple computing resources. Multiple virtual machines may also be used on a single processor. Memory 206 may include computer system memory or random access memory, such as DRAM, SRAM, EDO RAM, etc. Memory 206 may include other types of memory, or combinations thereof, as well.

[0079] A user may interact with computing device 200 through a visual display device 218 (e.g., a personal computer, a mobile smart device, etc.) that may display at least one user interface 220 (e.g., a graphical user interface), such as a computer monitor, that may be provided by an exemplary embodiment. Computing device 200 may include other input / output devices, such as a camera, keyboard, microphone, microscope, or any suitable multi-point touch interface 208, pointing device 210 (e.g., a mouse), for receiving input from a user. Keyboard 208 and pointing device 210 may be connected to visual display device 218. Computing device 200 may also include other suitable conventional input / output peripherals.

[0080] The computing device 200 may also include at least one storage device 224, such as a hard drive, CD-ROM, eMMC (Multimedia Card), SD (Secure Digital) card, flash drive, non-volatile storage medium, or other computer-readable medium, for storing data and computer-readable instructions and / or software for implementing exemplary embodiments of the systems described herein. The exemplary storage device 224 may also store at least one database 226 for storing any suitable information necessary to implement the exemplary embodiments. For example, the exemplary storage device 224 may store at least one database 226 for storing information. The database 226 may be updated manually or automatically at any suitable time to add, delete, and / or update one or more items in the database.

[0081] The computing device 200 may include a network interface 212 configured to connect to one or more networks, such as a local area network (LAN), a wide area network (WAN), or the Internet, via at least one network device 222 through a variety of connections, including, but not limited to, a standard telephone line, a LAN or WAN link (e.g., 802.11, T1, T3, 56kb, X.25), a broadband connection (e.g., ISDN, Frame Relay, ATM), a wireless connection, a Controller Area Network (CAN), or some combination of any or all of the above. The network interface 212 may include a built-in network adapter, a network interface card, a PCMCIA network card, a Pa CI / PCIe network adapter, an SD adapter, a Bluetooth adapter, a Card Bus network adapter, a wireless network adapter, a USB network adapter, a modem, or any other device suitable for connecting the computing device 200 to any type of network capable of communicating and performing the operations described herein. Moreover, computing device 200 may be any computing system, such as a workstation, a desktop computer, a server, a laptop, a handheld computer, a tablet computer (e.g., a tablet computer), a mobile computing or communication device (e.g., a smartphone communication device), an embedded computing platform, or any other form of computing or telecommunication device capable of communicating and having sufficient processor power and memory capacity to perform the operations described herein.

[0082] Computing device 200 may run any operating system 216, such as, for example, any version of the Microsoft® Windows® operating system, various releases of Unix and Linux® operating systems, any version of MacOS® for Macintosh computers, any embedded operating system, any real-time operating system, any open source operating system, any proprietary operating system, or any other operating system capable of running on a computing device and performing the operations described herein. In an exemplary embodiment, operating system 216 may run in native mode or in an emulated mode. In an exemplary embodiment, operating system 216 may run on one or more cloud machine instances.

[0083] 18 is a block diagram of an exemplary system environment 300 for controlling ammonia synthesis, according to an embodiment. The environment 300 may include servers 302, 304 configured to communicate with at least one of user devices 306, 308 (e.g., imaging devices, smart mobile devices, microscopes, etc.), a model 310, at least one processing device 312, at least one user interface 314, and a central computer processing system 318 via a communications platform 324, which may be any network through which information may be transmitted between devices communicatively connected to the network. For example, the communications platform 324 may be the Internet, an intranet, a virtual private network (VPN), a wide area network (WAN), a local area network (LAN), etc. In some embodiments, the communications platform 324 may be part of a cloud environment.

[0084] The environment 300 may include repositories or databases 320, 322 that may communicate with the servers 302, 304, as well as at least one user device 306, 308, the model 310, at least one processing device 312, at least one user interface 314, and a central computer processing system 318 via a communication platform 324. In an exemplary embodiment, the servers 302, 304, the at least one user device 306, 308, the model 310, the at least one processing device 312, at least one user interface 314, and the central computer processing system 318 may be implemented as computer processing devices (e.g., computer processing device 00). Those skilled in the art will recognize that the databases 320, 322 may be incorporated into at least one of the servers 302, 304. In some embodiments, the databases 320, 322 may store data related to ammonia synthesis models, ammonia synthesis guidelines, historical data, input images, reports, environmental data, neural networks, and combinations thereof, and such data may be distributed across multiple databases 320, 322.

[0085] All statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. In addition, such equivalents are intended to include both currently known equivalents and equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.

[0086] Various other components can be included or utilized to provide aspects of the teachings herein. For example, additional materials, combinations of materials, and / or omissions of materials can be used to provide additional embodiments that are within the scope of the teachings herein. The appropriateness of any particular component for carrying out the teachings herein should be determined from the perspective of the designer, manufacturer, seller, user, system operator, or other similar party, and such limitations should be recognized by the standards of that party.

[0087] In this disclosure, any element expressed as a means for performing a particular function is intended to encompass any way of performing that function, including, for example, a) a combination of circuit elements and associated hardware that perform that function, or b) software, including firmware, microcode, etc., as expressly set forth herein, in any form combined with appropriate circuitry for executing the software that performs the function. Applicant therefore considers any means that can provide those functions to be equivalent as set forth herein. Functional language used in the claims appended hereto should not be construed as "means-plus-function" language within the meaning of 35 U.S.C. 112(f) unless otherwise expressly expressed by the use of the words "means for" or "steps for" in each claim.

[0088] When introducing elements of the invention or embodiments thereof, the articles "a," "an," and "the" are intended to mean that there are one or more of the element. Similarly, the adjective "another," when used to introduce an element, is intended to mean one or more of the element. The terms "including" and "having" are intended to be inclusive so that there may be additional elements other than the listed elements. The term "exemplary" is not intended to be construed as the best example, but merely one of many possible examples.

Claims

1. 1. A system for producing ammonia, comprising: a reactor having an inlet, an outlet and a reactor region; and a bifunctional material within the reactor region, the bifunctional material configured to fix nitrogen on its surface when exposed to a nitrogen-containing gas and to result in the production of ammonia when exposed to a hydrogen-containing gas. A system including:

2. The system of claim 1 , wherein manufacturing occurs at a temperature of 300 degrees Celsius or less.

3. The system of claim 1 , wherein production occurs at atmospheric pressure.

4. The bifunctional material is LaNi 5、 LaNi 4.8 Sn 0.2 , NiBaH 2 , Ni 4 W, TiMo x [x=1-3], ZrMn x [x=1 to 3], Ni 3 Ga, MnNi 3 , Ni 3 Ge, Ce 2 MnN 3 , ZrCr, ZrCr 2 , Ni 2 Mo 3 N, LaCoSi, LaRuSi, Cs-Ru / MgO, and Co 2 Mo 3 N.

5. 10. The system of claim 1, further comprising an ammonia synthesis promoter within the reactor region, wherein the ammonia synthesis promoter is selected from the group consisting of sodium (Na), calcium (Ca), potassium (K), barium (Ba), ruthenium (Ru), and combinations thereof.

6. 10. The system of claim 1, further comprising a support material within the reactor region, the support material being selected from the group consisting of aluminum, lanthanum, magnesium, cerium oxide, and combinations thereof.

7. 10. The system of claim 1, further comprising a control system in communication with the reactor, the control system comprising machine-readable instructions for controlling one or more operating parameters associated with operation of the reactor for the production of ammonia.

8. 8. The system of claim 7, wherein the one or more operating parameters are selected from the group consisting of temperature, pressure, residence time, concentration, and humidity.

9. 1. A computer program product stored on a non-transitory machine-readable medium, comprising: Controlling the production of ammonia by operating a reactor having an inlet, an outlet, and a reactor region; and a bifunctional material within the reactor region configured to fix nitrogen on its surface when exposed to a nitrogen-containing gas and to cause the production of ammonia when exposed to a hydrogen-containing gas.

2. A computer program product comprising machine-readable instructions for:

10. 10. The computer program product of claim 9, wherein the control includes communication over a network including at least one of a controller having computing capability, one or more sensors, a power source, one or more electrically operated valves, one or more switches, and an interface.

11. 10. The computer program product of claim 9, wherein the control includes commanding a switch between gas supplies.

12. 10. The computer program product of claim 9, wherein the controlling includes instructions for monitoring the production of ammonia.

13. 13. The computer program product of claim 12, wherein the control includes instructions to operate the separator to recycle at least a portion of the unreacted nitrogen-containing gas and the unreacted hydrogen-containing gas.

14. 10. The computer program product of claim 9, wherein the controlling comprises instructions for maintaining the temperature of the reactor below a temperature of at least one of nitridation and ammonia decomposition.

15. 1. A system for producing ammonia, comprising: a reactor having an inlet, an outlet and a reactor region; a bifunctional material within the reactor region, the bifunctional material configured to fix nitrogen on its surface when exposed to a nitrogen-containing gas and to result in the production of ammonia when exposed to a hydrogen-containing gas; and A computer program product stored on a non-transitory machine-readable medium, the computer program product comprising machine-readable instructions for controlling production by managing the operation of a reactor. A system including:

16. 16. The system of claim 15 configured to provide ammonia to one of a fuel cell system, a refrigeration system, a selective catalytic reduction (SCR) system, a system for producing chemical feedstocks, a system for producing synthetic fibers, a waste treatment system, a water treatment system, and an agricultural application.

17. 16. The system of claim 15 configured in one of a fixed, mobile, temporary or permanent installation.

18. 1. A method for producing ammonia, comprising: a. introducing into a reactor a bifunctional material configured to fix nitrogen on its surface when exposed to a nitrogen-containing gas and to result in the production of ammonia when exposed to a hydrogen-containing gas; b. Fixing nitrogen to the bifunctional material by introducing nitrogen into the reactor; c. stopping the introduction of nitrogen into the reactor; and d. producing ammonia through the reaction of hydrogen with the nitrogen fixed to each of the components of the bifunctional material by introducing hydrogen into the reactor; A method comprising:

19. 20. The method of claim 18, wherein the order of hydrogen introduction and nitrogen introduction is reversed.

20. 20. The method of claim 18, wherein the reactor operates at a first temperature when nitrogen is introduced into the reactor and the reactor operates at a second temperature when hydrogen is introduced into the reactor.

21. 21. The method of claim 20, wherein the first temperature is the same as the second temperature.

22. 21. The method of claim 20, wherein the first temperature is higher than the second temperature.

23. 21. The method of claim 20, wherein the first temperature is between 200°C and 900°C.

24. 21. The method of claim 20, wherein the second temperature is between 100°C and 400°C.

25. 19. The method of claim 18, wherein steps (b) to (d) are carried out under isobaric conditions.

26. 20. The method of claim 18, wherein the bifunctional material comprises an ammonia synthesis promoter selected from the group consisting of sodium (Na), calcium (Ca), potassium (K), barium (Ba), ruthenium (Ru), and combinations thereof.

27. 20. The method of claim 18, wherein the bifunctional material comprises a support material selected from the group consisting of aluminum, lanthanum, magnesium, cerium oxide, and combinations thereof.

28. 20. The method of claim 18, wherein a control system in communication with the reactor controls one or more operating parameters associated with operation of the reactor for the production of ammonia.

29. 30. The method of claim 28, wherein the one or more operating parameters are selected from the group consisting of temperature, pressure, residence time, concentration, and humidity.

30. 20. The method of claim 18, further comprising providing the ammonia to one of a fuel cell system, a refrigeration system, a selective catalytic reduction (SCR) system, a system for producing chemical feedstocks, a system for producing synthetic fibers, a waste treatment system, a water treatment system, and an agricultural application.

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