A compressor that uses electrochemical reactions to compress hydrogen quietly and efficiently has been developed. Suitable for urban hydrogen refueling, it is expected to expand in urban areas in the future.

The Korea Institute of Machinery and Materials (President Park Sang-jin), under the Ministry of Science and ICT, has successfully developed an electrochemical hydrogen compressor that compresses hydrogen using electrochemical reactions, through joint research with Chung-Ang University (President Park Sang-gyu). This innovative technology is expected to contribute to the revitalization of a hydrogen society.

A joint research team led by Research Director Seok-ho Yoon of the Thermal Energy Solutions Laboratory at the Carbon Neutral Machine Research Institute of the Korea Institute of Machinery and Materials, and Professors Min-seong Kim and Dong-gyu Kim of Chung-Ang University, successfully developed a hydrogen compressor by applying current to the separator used in the fuel cell to extract only hydrogen by utilizing the characteristics of fuel cells that generate electricity from hydrogen.

As hydrogen passes through the device through an electrochemical reaction, compression occurs as hydrogen accumulates at the rear end of the device. The research team designed the internal structure of the device to withstand high pressures during hydrogen compression, and maximized compression efficiency by preventing energy loss through internal surface treatment.

To store hydrogen in hydrogen vehicles, it must be compressed to 700 atmospheres. Therefore, hydrogen charging stations must be compressed to even higher pressures before supplying it. Charging hydrogen causes the pressure in the charging station's storage tank to drop, requiring a waiting period to build up the pressure. Fast and efficient hydrogen compression technology can reduce this waiting time, making it essential for building a hydrogen supply chain.

Existing mechanical compressors, utilizing various physical methods including pistons, suffer from unreliable durability and low efficiency. Furthermore, the compression process can contaminate the hydrogen, as lubricants used in the process can mix with it, and generate significant noise, necessitating improvement.

Conversely, electrochemical compressors, which simultaneously perform hydrogen purification and compression, can extract 99.99% hydrogen without contamination and compress it to high pressure. Furthermore, the compressors can be scaled to extract and compress hydrogen at any desired volume.

This compressor's compact size allows it to be used even in confined spaces. Recent attempts to install hydrogen charging stations alongside LPG charging stations have been hampered by the size limitations of high-pressure compressors. The use of electrochemical compressors is expected to alleviate this space constraint.

In addition to spatial advantages, it also offers quietness, making it very advantageous for installing hydrogen charging stations in urban areas. Even if it is not a hydrogen charging station, a small-scale compression system can be built anywhere hydrogen compression is needed, and it can also be applied to urban zero-energy houses that have recently been attracting attention.

Seok-ho Yoon, head of the Thermal Energy Solutions Lab at the Korea Institute of Machinery and Materials, said, “The electrochemical hydrogen compressor has the great advantage of being more space-efficient and quieter than existing mechanical compressors,” and added, “We will improve the performance of the compressor so that the technology can be commercialized, contributing to the revitalization of a hydrogen society beyond the spread of hydrogen charging stations in urban areas.”

Meanwhile, this research was conducted with the support of the Ministry of Trade, Industry and Energy's Alchemist Project, 'Development of a chemical absorption heat pump using an electrochemical compressor.'