South Korean airlines are set to fly planes powered in part by biofuel, making the country the 20th in the world to do so.

Called sustainable aviation fuel(SAF) and promoted as an alternative to fossil fuel, the new product is made by a domestic oil refiner and will be mixed with other fuels. 

Its use will begin Friday with a Korean Air flight bound for Haneda International Airport in Tokyo, the transport and energy ministries said Friday.

SAF is made from animal or plant sources, and the International Air Transport Association says it can reduce carbon dioxide emissions by as much as 80 percent. Aviation accounts for roughly 2 percent of global energy-related CO2 emissions.

In line with the International Civil Aviation Organization’s carbon regulations, which are set to become more stringent starting in 2027, Seoul intends to push for the mandatory use of a biofuel mixture on all international flights departing from the country.

The transport ministry pledged to seek ways to minimize any increase in airfares, possibly by introducing a carbon mileage system.