The Korea Institute of Machinery and Materials (KIMM), an institution under the jurisdiction of the Ministry of Science and ICT, has developed an innovative process that uses renewable energy to produce ammonia at room temperature and normal pressure. This technology is expected to make a significant contribution to achieving carbon neutrality in the future, through the development of an ammonia production process that produces zero carbon emissions.

Led by Principal Investigator Dr Dae Hoon Lee, the KIMM Research Team in the Plasma Engineering Department has successfully developed an innovative carbon-free process to produce ammonia. On August 5, they published their research results in ACS Energy Letters.

The organic process for the synthesis of ammonia (Haber-Bosch method), developed by Fritz Haber and Karl Bosch in 1913, produces ammonia used as a fertilizer, and is considered a discovery that significantly increased agricultural productivity and has served as the basis for agriculture innovation. Recently, ammonia has gained attention as an environmentally friendly zero carbon fuel. This is because ammonia, which is a compound of nitrogen and hydrogen, does not emit carbon dioxide even when burned.

However, to synthesize ammonia using the Haber-Bosch method, conditions of high pressure and high temperature must be met, with a pressure of at least 200 atm and a temperature of at least 400 degrees Celsius. . Additionally, since fossil fuels such as natural gas are used to produce hydrogen, a large amount of energy is consumed resulting in high levels of carbon dioxide emissions.

According to a 2020 Royal Society report, the Haber-Bosch method consumes around 1.8% of the world’s energy to produce ammonia, and the levels of carbon dioxide emitted in this process account for 1.8% of total carbon dioxide emissions in the world.

The ammonia production process developed by the KIMM research team involves combining water with a nitrogen plasma, thereby producing hydrogen and nitrogen oxides. These resulting oxides are reduced to ammonia with catalysts. Over 99% of the nitrogen oxides produced by this plasma reaction become nitric oxide, which can be easily reduced to ammonia. The nitro monoxide then reacts with the co-produced hydrogen to produce ammonia with over 95% high selectivity, and the heat generated during the plasma decomposition process is used for the catalytic synthesis process.

Since this process does not use any fossil fuels and is a technology capable of producing “green ammonia” with zero carbon dioxide emissions, it can achieve an efficiency 300 to 400 times that of existing production technologies. electrochemicals of ammonia, which are considered to be the main alternatives to the Haber-Bosch method.

In addition, this process can be scaled up relatively easily through a modular system due to the fact that the reaction occurs with water and nitrogen under ambient temperature / pressure conditions, as opposed to temperature conditions. / high pressures that must be met for existing methods of ammonia production. In addition, an aqueous solution of nitrate, a by-product generated as a result of the ammonia production process, can be used as an agricultural nutrient solution and oxidizing agent.

In the future, the KIMM research team hopes to improve the cost and efficiency of ammonia production by developing technology for scaling and commercialization. The team also aims to collaborate with domestic and foreign engineering companies to expand their efforts to ammonia plants, especially small and medium-sized plants that can operate at normal pressure and ambient temperature conditions.

Lead researcher Dr Dae Hoon Lee pointed out that he and his team have developed an environmentally friendly ammonia production process that can be applied to real facilities and, in theory, emits zero carbon. He also said that he and his team will do their best to carry out follow-up research and development activities to help significantly reduce global carbon emissions.

Provided by the National Science and Technology Research Council