Amogy develops an integrated energy system that uses liquid ammonia as a source material, cracks ammonia into hydrogen energy source, and uses hydrogen fuel cells to provide electric power to various transport carriers, including drones, automobiles, tractors, trucks, marines, and even airplanes. Amogy’s integrated energy system enables the decarbonization of commercial transportation, a field in which existing and emerging technologies are severely constrained by their low energy densities.
Challenges: hydrogen fuel
Hydrogen gas (H₂) can be used as a source of clean energy for a variety of applications. It has a distinct advantage over other fuels such as diesel, gasoline, and jet fuel, which have a specific energy of about 45 MJ/kg, and lithium-ion batteries, which have a specific energy of about 0.95 MJ/kg. In contrast, hydrogen has a specific energy of over 140 MJ/kg, which means that 1 kg of hydrogen is equivalent to 3 kg of gasoline or kerosene. This can help reduce the amount of fuel required to produce the same amount of energy. Additionally, hydrogen-powered systems typically produce only water as a byproduct and have minimal or no greenhouse gas emissions, minimizing their environmental impact.
95% of the world’s hydrogen (over 60 million tons) is currently produced by steam methane reforming (SMR) process, which requires substantial energy input and emits a significant amount of CO₂. In addition, hydrogen produced at industrial SMR plants must travel a great distance to reach its users. Hydrogen transportation involves either pressurizing the hydrogen gas or cryogenically cooling the hydrogen gas to -253 ºC to create liquid hydrogen. The International Energy Agency estimates that the costs of hydrogen transportation could be three times that of its production.
The book Hydrogen Revolution isn’t just a manifesto for a powerful new technology. It’s a hopeful reminder that despite the gloomy headlines about the fate of our planet, there’s still an opportunity to turn things around. (see on Amazon)
Amogy has developed an integrated energy system that uses liquid ammonia (NH₃) as a source material, decomposes NH₃ into hydrogen energy source, and uses hydrogen fuel cells to generate high electrical power of at least 5 kilowatts with a high energy density of at least 655 Wh/kg or 447 Wh/L. The energy system can power transport carriers from small drones to marines, enabling the decarbonization of commercial transportation.
The diagram below depicts a compact 5 kW-energy system capable of powering a drone.
The system includes a liquid NH₃ storage tank, a startup reactor, a main reactor, catalysts, a heat exchanger, an adsorption tower, a hybrid battery, hydrogen fuel cells, and additional components including controllers and sensors (not shown).
- NH₃ tank
The NH₃ tank stores liquid NH₃ at a pressure and temperature between 7 and 12 bar and 15 and 30 ºC.
- Startup reactor
The startup reactor comprises conductive catalysts and electrodes. The catalysts can be rapidly electrically heated by a hybrid battery to catalyze the decomposition of NH₃ at an efficiency of 90%. A plurality of startup reactors can be stacked on top of each other to form a startup reactor module.
- Main reactor
The main reactor comprises catalysts, an electrical heater, and a combustion heater. The heaters heat the catalyst to a high temperature (over 500 ºC) to catalyze the decomposition of NH₃ with a 90% efficiency.
The catalysts in both reactors comprise a metal foam catalyst, which comprises nickel (Ni), iron (Fe), chromium (Cr), cobalt (Co), molybdenum (Mo), copper (Cu), aluminum (Al), or theri alloys. The metal foam catalyst comprises a catalytic coating, which comprises a metal material, a promoter material, a support material, or any combination thereof.
The active metal material comprises ruthenium (Ru), nickel (Ni), rhodium (Rh), iridium (Ir), cobalt (Co), molybdenum (Mo), iron (Fe), platinum (Pt), chromium (Cr), palladium (Pd), or copper (Cu).
The promoter material is selected from sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), magnesium (Mg), calcium (Ca), strontium (Sr), or barium (Ba).
The support comprises are selected from alumina (Al₂O₃), magnesium oxide (MgO), cerium(IV) oxide (CeO₂), zirconium dioxide (ZrO₂), Lanthanum(III) oxide (La₂O₃), silica (SiO₂), yttrium oxide (Y₂O₃), titanium dioxide (TiO₂), silicon carbide (SiC), hexagonal boron nitride (BN), BN nanotubes, zeolites, LaAlO₃, CeAlO₃, MgAl₂O₄, or CaAl₂O₄.
The metal foam catalyst has an apparent electrical resistivity of at least about 8 micro ohm-meters (μΩm). The metal foam catalyst is processed using etching, leaching, or acidic treatments to enhance the surface area of the metal foam catalyst. The metal foam catalyst is heat treated and thermally activated. The metal foam catalyst is coated using a physical vapor deposition or chemical vapor deposition treatment.
The figure below schematically depicts an example of a highly active catalyst for NH₃ decomposition.
Catalysts comprises Ru active metal and CeO₂-doped ZrO₂ supports. The incorporation of the cerium into the ZrO₂ framework generates a solid solution with a tetragonal phase that has a high density of surface oxygen vacancies and a low density of surface hydroxyl groups. The high density of surface oxygen vacancies increase the Ru- support interaction, while a lower density of surface hydroxyl groups promotes NH₃ conversion efficiency.
- Heat exchanger
The heat exchanger transfers heat from the hot output fluid flow of the main reactor to the input fluid flow of the main reactor. Thus, the output fluid temperature is reduced, which is desirable for the adsorption tower, while the input fluid of the main reactor is preheated, which reduces the heating load of the main reactor and increases energy efficiency.
- Adsorption tower
The adsorption tower removes unreacted NH₃ from the output fluid flow of the main reactor to provide pure H₂ to hydrogen fuel cells.
- Hydrogen fuel cell
Hydrogen fuel cells receive H₂ from the output fluid flow of the adsorption tower and generate electrical power.
- Hybrid battery
The hybrid battery provides power for load following and initial reactor heating.
- Controllers, sensors
Controllers control NH₃ flow rate, air flow rate, flow pressures, valves, hydrogen fuel cell power output, battery power output, and electrical heater output. Sensors measure temperatures, pressures, fuel cell power output, battery power outputs, battery state of charge, fuel cell hydrogen consumption, and NH₃ conversion efficiency.
How does this energy system function? The operation of the energy system comprises a startup process and a steady process.
The startup process is depicted in the flow diagram below followed by a brief description of each step.
- (1) Electrically heating a startup reactor to 550 ºC within 5 min;
- (2) Inputting NH₃ from the storage tank with an initial target flow rate to the startup reactor. NH₃ decomposes into H₂ and nitrogen gas (N₂) with a conversion efficiency of 90%;
- (3) Inputting air and a fraction of an exit flow from the startup reactor to a main reactor which has a combustion heater and a electrical heater;
- (4) Igniting the combustor at the main reactor and adjusting the flow rate of air into the main reactor;
- (5) Heating the main reactor to a target temperature;
- (6) Turning off the startup reactor;
- (7) Using a controller, increasing the NH₃ flow rate to a target flow rate and simultaneously controlling and increasing the main reactor air flow rate to maintain the target main reactor temperature. NH₃ decomposes into H₂ and N₂;
- (8) Inputting a portion of an exit flow from the combustor reactor to a fuel cell;
- (9) Reacting the exit flow from the combustor reactor in the fuel cell to generate electrical power;
- (10) Inputting a portion of an exit flow from the fuel cell to the combustor reactor;
- (11) Adjusting the combustor reactor air flow rate to maintain a target main reactor temperature;
- (12) Adjusting the NH₃ flow rate to a target flow rate (e.g., by fine-tuning or decreasing/increasing the NH₃ flow rate), and/or adjusting the combustor reactor air flow rate to maintain a target main reactor temperature; and
- (13) Achieving a predetermined initial operational condition (i.e., a steady-state condition).
How can the power output of the hydrogen fuel cell that powers the load be maintained or adjusted once the startup condition has been met?
Various operational parameters, including air flow rate for the combustor reactor, NH₃ flow rate into the system, and/or fuel cell hydrogen utilization, can be adjusted to maintain or adjunct the power output of the hydrogen fuel cells. The following flow diagram illustrates how incremental or decremental changes in NH₃ flow rate based on predetermined value and/or percentage of current value can increase or decrease the power output for the hydrogen fuel cell.
The figure below shows an example of the compact energy system that can power a drone.
The figure below schematically illustrates an over 100 kW-energy system that can power cars, trucks, marines, and airplanes.
The over 100 kW-energy system is comparable to the compact 5 kW-energy system described previously, with the addition of at least two adsorbent towers. The adsorbent towers contain an adsorbent material. Two adsorbent beds are utilized for on-demand adsorbent regeneration and continuous operation of the energy system.
The first adsorption tower is used for the first time period, while the second adsorption tower is on standby ready to be used. Once the first adsorption tower has been fully discharged, the system switches the flow path of the main reactor’s exit flow to the second adsorption tower. The second adsorption tower is used to remove any traces of ammonia from the exit flow before the exit flow is directed to hydrogen fuel cells. During operation of the second adsorption tower, the first adsorption tower is regenerated. When the second adsorption tower has been completely discharged, the first adsorption tower is regenerated and made available for use in another cycle or operation.
The figure below depicts an example of the over 100 kW-energy system that can power a car, a tractor, a truck, a marine, and even an airplane.
- US20220389864A1 Systems and methods for processing ammonia
- WO2022261488A1 Systems and methods for processing ammonia
- US20220395810A1 Systems and methods for processing ammonia
- US11539063B1 Systems and methods for processing hydrogen
- WO2022241260A1 Systems and methods for processing ammonia
- US20220364505A1 Renewable fuel power systems for vehicular applications
In July 2021, Amogy integrated a 5 kW-energy system into a drone.
In May 2022, Amogy integrated a 100 kW-energy system into a John Deere tractor, as shown in the video below.
In 2023, Amogy integrated a 300 kW-energy system into a semi truck, which is displayed in the following video.
Following this successful freight truck testing, Amogy will continue to pursue strategic partnerships across the global shipping and transportation industries. This includes the company’s 1 MW-scale ammonia-powered tugboat to be presented later in 2023, and other commercial deployments.
Amogy is funded by 7 investors, including AP Ventures, Amazon, DCVC, Collaborative Fund, Newlab, SK Innovation, and Saudi Aramco Energy Ventures. Newlab and Saudi Aramco Energy Ventures are the most recent investors.
Seonghoon Woo is CEO.