Korea: Fuels
Background
South Korea utilizes a co-regulatory framework to govern its fuel supply, splitting legal authority between the Ministry of Environment (MOE) and the Ministry of Trade, Industry and Energy (MOTIE).
The MOE establishes emission-focused chemical properties—such as sulfur, aromatics, olefins, and benzene—under the Clean Air Conservation Act. The actual legally mandated limiting values are included in the Enforcement Rules of the Clean Air Conservation Act [6816].
MOTIE dictates core commercial and technical specifications—such as density, distillation properties, and renewable fuel blending limits—under the Petroleum and Alternative Fuel Business Act. Its actual numerical limits are detailed in the ministerial decree, the Notification on Fuel Quality Standards, Inspection Methods, and Fees [6817].
These laws are translated into industry practice by two additional bodies. The Korean Agency for Technology and Standards (KATS), the national standards body under MOTIE, develops and updates Korean Industrial Standards (KS) (such as KS M 2611 for gasoline and KS M 2614 for diesel). The Korea Petroleum Quality & Distribution Authority (K-Petro) is responsible for direct field enforcement and monitoring for the government, monitoring downstream logistics networks, collecting field samples from retail sites and ports, fuel testing, and managing industry-wide tax and levy collections.
Diesel Fuel
Korean Industrial Standards applicable to diesel engines include:
- KS M 2610 Automotive Diesel [6818]
- KS M 2965 Biodiesel / FAME used in blends with automotive diesel or BD20 [6819]
- KS M 2619 Biodiesel fuel oil (BD20) [6822]
- KS M 2614 Types A, B and C heavy fuel oil that can be used as fuel in internal combustion engines, boilers and furnaces
- KS M 2460 Marine biofuel
While commercial diesel fuel specified by KS M 2610 is limited to a maximum of 7% FAME, B20 (B10 in winter) is allowed for closed fleet applications such as bus companies, trucking fleets, and construction operators who maintain their own certified storage tanks and internal repair shops. MOTIE establishes technical specifications for BD20 in the Notice on Quality Standards, Inspection Methods, and Inspection Fees for Petroleum Substitute Fuels that are reflected in KS M 2619 [6820].
Gasoline
Korean Industrial Standards applicable to spark ignition engines include
- KS M 2612 Automotive Gasoline [6821]
- KS M 2615 Liquefied Petroleum Gas - LPG
- KS M 2970 Bio-ethanol for Fuel Blending
Automotive gasoline is available in two grades, Grade 1 (Regular) has RON from 91-94 and Grade 2 (Premium) has RON 94 or higher. Sulfur is limited to a maximum of 10 mg/kg. Gasoline is allowed to contain a maximum of 2.3% oxygen by mass with MTBE (methyl t-butyl ether), ETBE (ethyl t-butyl ether), TAME (tertiary amyl methyl ether), and bioethanol being acceptable oxygenates. However, MTBE is the dominant oxygenate used commercially.
For natural gas as a vehicle fuel, South Korean relies on ISO 15403.
Renewable Fuels
South Korea’s use of renewable fuels for transportation is limited to blending biodiesel into the diesel fuel pool. The program started with a pilot project in 2002 limited to the Seoul metropolitan area that transitioned to a voluntary national biodiesel blending target of 0.5% in 2007 and 2.0% in 2010. During this period, BD20 was introduced for captive commercial fleets. In 2012, a 2.0% target became mandatory.
In 2015, a Renewable Fuel Standard (RFS) program under the Renewable Energy Act placed statutory obligations directly onto petroleum refiners and fuel importers to blend renewable fuels. The blend target rose to 2.5% in July 2015 and 3.0% in 2018. Further legislation increased the target to 3.5% in 2021, 4.0% in 2025, 4.5% in 2027 and 5.0% in 2030. In 2022, an additional requirement of 3% HVO was added to the 2030 target bringing the total 2030 requirement to 8% (5.0% biodiesel + 3.0% HVO).
While an ethanol blend level of about 6.6% is possible based on the oxygen limit in gasoline, very little ethanol is used. Challenges to introducing ethanol blended gasoline include a reluctance to relying on imports to meet an ethanol blending mandate for light-duty vehicles due to low domestic fuel grade ethanol production capacity and the cost of infrastructure upgrades to make the distribution system compatible with ethanol blended gasoline. Efforts to implement an E10 mandate have been unsuccessful.
An SAF blending mandate of 1% for all international departures takes effect in 2027 that rises to 7-10% in 2035. To meet this demand, South Korea's major energy firms are investing in Alcohol-to-Jet (ATJ) technology to convert imported bioethanol into jet fuel.