Korea to Become Hydrogen Importer Following Oil... Completion of Next-Generation Core Technology Development

Korea Institute of Energy Research "Develops Core Technology for Pressurized Ammonia Decomposition Reactor for Hydrogen Production"
Reduces Catalyst Usage to One-Tenth of Previous Amount, Lowers Cost, and Completes Stability Verification

[Asia Economy Reporter Kim Bong-su] Hydrogen is emerging as the next-generation clean fuel to replace petroleum in overcoming global warming. Countries worldwide are focusing on developing technologies to mass-produce hydrogen cheaply without carbon emissions. South Korea, however, must import hydrogen following petroleum because it cannot produce sufficient clean electricity due to limited sunlight. In response, Korean researchers have succeeded in developing a core technology that enables hydrogen production from ammonia, which is much cheaper and more stable than existing methods.

On the 11th, the Korea Institute of Energy Technology announced that Dr. Jeong Un-ho’s hydrogen research team developed the country’s first pressurized ammonia decomposition reactor core technology for hydrogen production using ammonia as a raw material. South Korea, which imports petroleum due to shortages, unfortunately faces an inevitable situation of importing hydrogen, the next-generation clean fuel. Currently, hydrogen is produced by decomposing methane extracted from liquefied natural gas (LNG), but this process emits large amounts of carbon, which does not help solve global warming. Water electrolysis technology, which produces hydrogen by splitting water, remains costly and has clear limitations. The high cost and production instability of renewable energy sources such as solar and wind power have not been resolved, forcing reliance on thermal and nuclear power generation, preventing truly 'clean energy.'

Accordingly, South Korea must import 'clean hydrogen' produced overseas through renewable energy, just as it imports petroleum, and ammonia is considered the most suitable 'carrier.' Ammonia is already widely used as a carbon-neutral fuel for ships and power generation, and it is overwhelmingly more cost-effective and efficient than importing liquefied hydrogen (cryogenic) or liquid organic compounds. Ammonia has a hydrogen storage density 1.7 times higher per unit volume than liquefied hydrogen, enabling large-capacity storage. It also liquefies relatively easily at ambient temperature and pressure and has a well-established international transportation and distribution infrastructure. Desert countries like Saudi Arabia, with sunlight dozens of times greater than South Korea, have plans to produce large quantities of clean hydrogen using cheap electricity and sell it to South Korea and other East Asian countries.

The research team devised a core technology to produce clean hydrogen by decomposing ammonia. The process of producing high-purity hydrogen by decomposing ammonia consists of three stages. First, ammonia is decomposed into nitrogen and hydrogen at high temperature, and unreacted residual ammonia is removed at ambient temperature. Then, hydrogen is separated in a pressure swing adsorption (PSA) process at ambient temperature to produce high-purity hydrogen exceeding 99.97%. The team developed the reactor and catalyst that decompose ammonia into nitrogen and hydrogen, which is the core of hydrogen production. The ammonia decomposition reactor developed by the team applies heat to eight reactor tubes filled with donut-shaped metal structured catalysts centered around a burner, where ammonia passes through the catalyst and decomposes into hydrogen and nitrogen. It is important to supply the same amount of ammonia to each reactor and maintain the temperature.

The team used a self-designed ammonia distributor to supply ammonia uniformly to each reactor and derived optimal conditions for ammonia decomposition through experiments on various variables such as the distance and position between the burner and reactors. Additionally, the high-temperature decomposition gas generated by the reaction was heat-exchanged and reused to preheat the ammonia feedstock, improving decomposition efficiency.

In particular, they developed a technology to directly coat nanocatalysts on the surface of metal structures immersed in liquid based on the precipitation method. They localized the metal structured catalyst technology that reduces the use of expensive precious metals to one-tenth compared to commercial catalysts while maintaining ammonia decomposition performance. For heat-supply-required reactions like ammonia decomposition, metal structured catalysts with excellent heat transfer properties are preferred, but catalyst peeling was a major obstacle. The team applied their proprietary coating technology to uniformly and thinly coat the catalyst on the metal structure surface, suppressing peeling and drastically reducing catalyst usage.

The ammonia decomposition catalyst reactor developed through three years of research since 2018 achieved over 90% ammonia decomposition efficiency by optimizing catalysts, reactors, heat exchangers, and operating conditions. Stability verification of each component was completed through 100 hours of operation. The team also supplied high-purity hydrogen produced through the three-stage process from ammonia to the hydrogen fuel cell stack of Hyundai Motor Company’s (a joint research partner) hydrogen electric vehicle Nexo and confirmed stable production of 20 kW power for 50 hours. The team is preparing to develop a large-capacity reactor of 1000 Nm3/h (approximately 90 kg/h) considering the activation of the ammonia-based clean hydrogen industry and future large-scale ammonia imports.

Dr. Jeong said, "We confirmed that large-scale green hydrogen production is possible through the high-efficiency ammonia decomposition catalyst reactor technology developed this time, which means that when importing clean hydrogen in ammonia form from overseas in the future, economical hydrogen can be supplied using the developed technology." He added, "Ammonia hydrogen carriers are attracting great interest not only in South Korea but also in Japan, Australia, Europe, and worldwide, so if large-scale demonstration is completed, overseas expansion of domestic technology will also be possible."

This content was produced with the assistance of AI translation services.