Ammonia Synthesis Small in Japan: Decentralizing Ammonia-Production
In the land of the rising sun, researchers have developed a new technology for small-scale ammonia production: The compact ammonia synthesis systems can enable smaller countries to establish their own decentralized NH3 production and could play an important role in the decarbonization of the industry. As so often, a sophisticated catalyst is the enabler.
Colorants, salts, refrigerants, and fertilizer: Ammonia is an important raw material in the chemical industry, and around 150 million tons of it are produced annually worldwide. About 99 percent of global ammonia production is based on the Haber-Bosch process, developed more than 100 years ago, in which hydrogen reacts with nitrogen at high pressure and temperature over an iron catalyst to form ammonia. However, this world-scale process has one big disadvantage: the required pressure and high temperatures make small-scale production unprofitable.
A young company from Japan, Tsubame BHB, has accepted the challenge and developed small ammonia plants. The core of the technology is a new electride catalyst developed at the Tokyo Institute of Technology in a publicly funded strategic research project of the Japan Science and Technology Agency (ACCEL Program, scientific director: Prof. Hideo Hosono, program manager: Toshiharu Yokoyama).
An electride is a compound in which an electron is ionically bound to a positively charged skeleton and the electron acts as an anion. The catalyst used for the ammonia synthesis carries nanoscale metal particles on the electride, and on these surfaces the electrons easily split the nitrogen molecules into atoms and thus enable the reaction with hydrogen. As a result, the triple bond between nitrogen and nitrogen can be split with less energy, and a highly efficient ammonia synthesis can be realized under conditions of low temperature and low pressure.
Any Country Can Produce their Own Raw Material
Tsubame BHB was founded in April 2017 to further develop the new catalyst technology and market the process worldwide. The main investors in the new company are the Japanese food manufacturer Ajinomoto as well as the UMI I investment fund from Universal Materials Incubator. The aim is to commercialize the world’s first model of “on-site ammonia production” and produce the required amount of ammonia directly where it is consumed.
Demand should be a given: currently, there are more than 120 countries in the world that do not have their own ammonia production. Many companies in these countries shy away from investing in the construction of large ammonia plants based on the Haber-Bosch process. The high investment sums and a resulting production capacity that would far exceed domestic demand make it not cost-effective. In addition, there are often not enough resources such as hydrogen and energy available to operate such a large plant.
A decentralized small-scale on-site ammonia plant from Tsubame BHB is on one hand cheaper to purchase. On the other hand, its capacity can be adapted to the demand and the availability of resources in the country concerned. Another advantage of ammonia synthesis on a small scale is the good opportunity to work with renewable energy sources and renewably produced hydrogen.
On-Site Production of Ammonia
Indeed, the area for wind or solar energy generation needed for a large Haber-Bosch system would cover several football fields. The small ammonia plants developed by Tsubame BHB, on the other hand, require around five wind turbines to operate a plant with a capacity of 3,000 tons of ammonia per year. The CO2 savings that result from the use of green hydrogen in contrast to hydrogen from steam reformers are immense.
For this reason, locally produced and locally consumed green ammonia with renewable energy is viewed by many as the standard for future ammonia use. The systems for on-site ammonia synthesis from Tsubame BHB enable small-scale production and can be operated using green hydrogen and renewable energies, so they actively contribute to the development of a green ammonia industry.
Tsubame BHB does not see itself in direct competition with the established Haber-Bosch process, but rather as an addition that can make a contribution to resource conservation and cost efficiency in many areas.
Moreover, on-site ammonia production also increases supply security. Situations in which chemical sites are having trouble getting deliveries of raw materials are becoming increasingly common. Breakdowns in transport infrastructure caused by heavy rain and floods are a typical example, but there are also the increasingly frequent days when low water in rivers and canals paralyzes shipping traffic. In this respect, the on-site production of ammonia on a small scale not only reduces the overall carbon footprint but also helps to ensure security of supply.