Japan: Fuels
Regulatory Requirements
Fuel quality requirements for Japanese fuels are mandated by the Law on the Quality Control of Gasoline and Other Fuels (Quality Assurance Law) [6791]. This law enables the Ministry of Economy, Trade and Industry (METI) to issue and update the Ordinance for Enforcement of the Act on the Quality Control of Gasoline and Other Fuels that specifies the limiting values of various fuel quality parameters [6792]. While the Quality Assurance Law and its ordinance were initially issued in the 1970s, they are periodically revised to ensure fuel quality requirements are updated as needed. Biofuel blending requirements are discussed below.
Diesel Fuels
The industrial standard for Japanese diesel fuel is JIS K 2204. It specifies five grades of diesel fuel. The main difference between each grade is the low temperature operability limits. The grades are: Special No. 1, No. 1, No. 2, No. 3, and Special No. 3 (1S, 1, 2, 3 and 3S). To provide fuel producers with flexibility to produce the different grades, the flash point, T90 distillation temperature, viscosity and cetane index will differ as well.
Since the 1990’s, the sulfur content in diesel fuels in Japan has been reduced in several steps, as follows:
- 0.2% = 2,000 ppm sulfur limit became effective from 1994
- 0.05% = 500 ppm S limit from 1997
- 50 ppm S limit is mandatory from 2005; in practice, 50 ppm S diesel was introduced nationwide from April 2003 through a voluntary effort of the Japanese petroleum industry
- 10 ppm S limit is effective from 2007; Japanese petroleum industry made a voluntary commitment to supply 10 ppm S fuel from January 2005 (nationwide, some island areas and Okinawa)
Highway vehicles (passenger cars, trucks and buses) normally use No. 2 diesel fuel. Special No. 3 diesel is used as the winter grade in Hokkaido and other cold climate areas. Most Japanese off-road equipment also uses No. 2 diesel fuel grade. While some industrial equipment is allowed to use fuel oil equivalent to Class 1/No. 1 specified by JIS K 2205 with a sulfur limit of 0.5%, the emissions from many of these applications are limited by Japan's Air Pollution Control Act rather than off-road vehicle standards.
Other Japanese distillate standards include JIS K 2203 for Kerosene and JIS K 2205 for heavy fuel oils.
The kerosene standard, JIS K 2203, covers two classes of kerosene. Class 1 is primarily for heating and cooking while Class 2 was historically intended for old kerosene-powered agricultural machinery and heavy industrial parts washing.
JIS K 2205 covers heavy fuel oils used in marine vessels, industrial boilers, power plants, and large off-road machinery. It categorizes fuel oils into three main classes based primarily on their kinematic viscosity, sulfur content, and carbon residue.
- Class 1 (Type A) is a light blend of about 90% diesel fuel (gasoil) and 10% residual oil and is split into No. 1 (Low Sulfur A-Fuel Oil, or LSAFO, sulfur ≤ 0.5%) and No. 2 (High Sulfur A-Fuel Oil, HSAFO, up to 2.0% sulfur).
- Class 2 (Type B) is an intermediate blend with mid-range viscosity and sulfur parameters.
- Class 3 (Type C) is a heavy, viscous residual fuel oil containing higher levels of sulfur, ash, and carbon residues and requires pre-heating to reduce viscosity before injection. It is divided into No. 1, No. 2, and No. 3 based on progressively higher viscosity limits (ranging up to 1000 mm2/s at 50°C).
Gasoline Fuels
Gasoline fuels are specified in JIS K 2202. It includes two types based on Research Octane Number which are further split based on ethanol/oxygen content, Table 1. Sulfur in gasoline is limited to 10 mg/kg (0.0010 % mass).
| Type 1 | Type 1E | Type 2 | Type 2E | |
|---|---|---|---|---|
| RON, min. | 96 | 89 | ||
| Ethanol, % vol. max. | 3 | 10 | 3 | 10 |
| Oxygen, % mass | 1.3 max. | 1.3-3.7 | 1.3 max. | 1.3-3.7 |
In Japan, direct blending of ethanol is very limited. Bio-ethyl tert-butyl ether (ETBE) produced from ethanol is used instead.
Under the Quality Control of Gasoline and Other Fuels Act, the direct blending of ethanol up to 3% volume in gasoline has been allowed since 2003. The oxygen content in E3 gasoline is limited to less than 1.3% mass which would be achieved with 8.3% ETBE (equivalent to 3.5% directly blended ethanol).
The Quality Control Act also allows E10 for use by vehicles that the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has certified as “E10/ETBE22” compatible. E10 gasoline can contain between 3 to 10% directly blended ethanol. The maximum blend level for ETBE is approximately 22% (ETBE22) under the E10 gasoline standard.
E20/ETBE44 gasoline grades are planned for the introduction by 2040.
JIS K 2190 specifies fuel ethanol (E100) used as a base material for automotive gasoline as defined in JIS K 2202, as well as fuel ethanol used as a raw material for ETBE.
While JIS K 2202 allows up to up to 7% MTBE, MTBE has been voluntarily phased out of use in Japan since 2001.
Renewable Fuels
In 2009, to encourage the replacement of fossil fuels with renewable energy sources, the “Act on Promotion of Use of Non-Fossil Energy Sources and Effective Use of Fossil Energy Raw Materials by Energy Suppliers,” also known as the Sophisticated Methods of Energy Supply Structure Act was enacted. This Act directed the Ministry of Economy, Trade and Industry (METI) Minister to develop policies and guidelines (i.e., METI notifications) for each energy sector. For transportation fuels, METI notifications under this act have included [6794]:
- Notification 1.0, in effect from 2011 to 2017, laid the groundwork for the decision to use bioethanol to fulfil its biofuel commitment for on-road transportation. It introduced a target volume of 210 million LOE (Liters Oil Equivalent) in 2011 rising to 500 million LOE by 2017. Only ethanol based on Brazilian sugar cane was provided with a default GHG intensity value. A GHG reduction target of 50% for biofuel was required, i.e., the carbon intensity needed to be 50% lower than petroleum gasoline.
- Notification 2.0, in effect from 2018 to 2022, maintained the 500 million LOE blending target but added a default emission value for US based corn ethanol. The GHG reduction target was raised to 55%.
- Notification 3.0, in effect from 2023 to 2027, updated the default GHG emission values and maintained the 500 million LOE blending target.
The scope of the above Notifications is limited to fuel produced by the Petroleum Association of Japan (PAJ) member companies. These refiners have met the annual biofuel target volume target largely through the imports of bio-ethyl tert-butyl ether (ETBE) derived from bioethanol, as well as a small volume of domestically produced bio-ETBE from imported bioethanol. 500 million LOE represents approximately 824 million liters of bioethanol.
Fuel distributed by non-PAJ companies is not subject to the Sophisticated Methods of Energy Supply Structure Act and any biofuel used by them is not counted towards the biofuel target. There is limited distribution of directly blended E3 and E10 by these companies.
The USDA estimates that Japan’s bioethanol consumption in the form of bio-ETBE for on-road fuel at 811 million liters in 2023, equivalent to a 1.8% ethanol blend rate for gasoline [6795].
In 2025, METI discussed a plan to introduce an E10/ETBE22 gasoline option by 2030 and an E20/ETBE44 gasoline option by 2040. While ETBE will continue to be used, direct blends of ethanol in gasoline are also planned. Other changes that are planned include raising the GHG emissions reduction target to 60% and adding default GHG emission values for ethanol derived from Brazilian corn, Thai sugarcane, and Thai cassava [6793][6794].
The adoption of sustainable aviation fuel (SAF) is a key component of the plan to increase the utilization of biofuels in the transportation sector. The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) is aiming to replace 10% of conventional jet fuel with SAF by 2030.
In 2024, Japan’s on-road biodiesel use remained very limited at about 10 million liters. Biodiesel is derived primarily from domestically from used cooking oil (UCO) in addition to other fats and oils. As the competition to procure UCO intensifies, biodiesel manufacturers have had difficulty securing sufficient UCO supplies.