A research team led by Principal Researcher Young Kim from the Heat Pump Research Center of the Research Institute of Carbon-neutral Energy Machinery of the Korea Institute of Machinery and Materials (KIMM) has successfully developed a highly efficient microchannel reactor which reduces the required catalyst amount to 30% for electrofuel production, yet offers a capacity 30 times greater than current reactors.

This reactor is safe at high temperature and pressure and is easy to remove heat, so the temperature setting is flexible, making it advantageous for e-fuel production.

Prototype of microchannel reactor. Credit: KIMM

The production of electrofuels involves synthesizing green hydrogen with carbon dioxide, a process that generates significant amount of heat. Consequently, a crucial technology is needed to effectively dissipate this heat. The reactor developed by the KIMM employs a novel approach of fusing plates with a layered microchannel structure through a high-temperature method rather than using adhesives. This design enables the reactor to excellently manage heat, even at elevated temperatures.

The electrofuels generated using the reactor created by the KIMM’s research team exhibit a cetane index of 55.7, satisfying the domestic requirement for vehicle diesel, which mandates a cetane index of at least 52. This index aligns closely with the cetane numbers of diesel sold by Korean refineries, typically ranging from 54 to 57.

Conventionally, slurry reactors or fluidized bed reactors (FBRs) are used when excessive heat is generated during the fuel synthesis process, but these are effective in large-scale production. As the amount of hydrogen produced from the surplus power in decentralized renewable power plants is relatively small, applying a large-sized reactor has the disadvantage of inhibiting economic efficiency.

Leveraging the existing technology for microchannel heat exchangers, the KIMM’s research team engineered a compact, highly efficient microchannel reactor. During testing, it was confirmed that 93% of the synthetic gas was converted into fuel. The development of a production process for electrofuels, compact enough to fit within a cargo container, could eventually lead to the establishment of eco-friendly fuel stations dispensing electrofuels.

This research was facilitated by the project for the “development of a microchannel reactor for power-to-fuel systems,” one of the basic projects of the KIMM.

Founded in 1976, the Korea Institute of Machinery and Materials (KIMM) is a non-profit government-funded research institute under the Ministry of Science and ICT.