The Korea Electrotechnology Research Institute (KERI) has developed a special gas that can replace SF6 (sulfur hexafluoride), a special gas with a high global warming index, and expectations are high that this will greatly contribute to reducing carbon emissions in the future.

KERI announced on the 1st that it has developed the world's best 'eco-friendly insulating gas' to replace SF6 (sulfur hexafluoride), the main culprit of global warming in the electric power equipment field, and has developed design technology that can apply it to ultra-high voltage transmission circuit breakers.

Electrical equipment must naturally conduct electricity well, but it also needs an 'insulation' function to block electricity in case of an accident and for safety reasons.

SF6 gas has excellent insulation performance and, compared to any other gas, its arc-extinguishing performance for blocking fault currents in the event of a system failure is far superior, and has been used in the power equipment field for over 50 years.

On the other hand, SF6 has a global warming potential that is 23,500 times that of carbon dioxide, and once leaked into the atmosphere, it exists for a whopping 3,200 years, causing adverse effects on the environment.

In Korea, SF6 gas accounts for a significant portion of total greenhouse gas emissions from KEPCO, so research on developing alternatives is urgently needed to respond to the climate crisis and achieve carbon neutrality.

There is a lot of effort worldwide to develop an eco-friendly gas that can replace SF6.However, it is a situation where the difficulty and challenge required are greater than that of new drug development, and thus, it has not brought about definite results.

Despite this high possibility of failure, KERI began related research and development with the great expectations that the successful development of SF6 alternative gas would bring and a sense of mission as a national research institute that must respond to global carbon emission regulations.

First, among the gases currently used in the industrial sector, substances with low global warming potentials were classified as priority, and the electrical and chemical properties of the selected first group of candidates were precisely analyzed to determine the second group of candidates. Afterwards, the final candidate materials were selected through the results of insulation and explosion/ignition control performance tests, and the optimal ratio for application to power equipment was derived to develop an eco-friendly insulating gas. KERI named this independently developed gas 'K6'.

K6 gas is environmentally friendly with a global warming potential of less than 1, and does not contain any serious toxic components. It also has a low boiling point (-26℃), which is an essential condition for applying gas to electric power devices, so it has stable gas properties in most areas.

KERI further developed the K6 gas and applied it to an ultra-high voltage (145 kW) transmission-grade circuit breaker, and passed the circuit breaker performance test according to the international standards of the International Electrotechnical Commission (IEC).

In particular, ultra-high voltage transmission circuit breakers are considered the most difficult field to apply insulating gas to. Based on passing this test, KERI plans to apply K6 gas to various power equipment (circuit breakers, transformers, switches, etc.) from distribution to transmission.

KERI Eco-friendly Power Equipment Research Center Director Oh Yeon-ho said, “K6 gas is more environmentally friendly and has better performance than the insulating gases that advanced overseas companies have been using,” adding, “Since our country ranks at the top in exports in the global power equipment industry, the development of K6 gas will have a huge impact not only on the environment but also on the economy and industry.”

The research team plans to prepare for commercialization through technology transfer with domestic power equipment companies. In addition, the goal is to contribute to strengthening the competitiveness of the domestic power equipment industry by establishing clear design standards for the wide use of eco-friendly gases through continuous communication with industrial sites.

Meanwhile, KERI is a government-funded research institute under the National Research Council of Science and Technology of the Ministry of Science and ICT. This research was conducted in collaboration with the Korea Research Institute of Chemical Technology, the Korea Research Institute of Standards and Science, the Korea Fusion Energy Research Institute, and the Korea Institute of Safety Assessment.