Japan is moving to broaden its biofuel sustainability framework by proposing new default greenhouse gas (GHG) emissions values for Thai sugarcane ethanol, Brazilian corn ethanol and Thai cassava ethanol, a step that could influence future global biofuel trade and strengthen the role of low-carbon ethanol in the Japanese market.
According to a report by the USDA Foreign Agricultural Service, Japan’s Ministry of Economy, Trade and Industry released the proposed emissions benchmarks on April 17 as part of efforts to enhance lifecycle emissions standards for transportation biofuels, Ethanol Producer Magazine reported.
The initiative builds on Japan’s liquid transportation biofuel standards covering fiscal years 2023-2027. Under the framework, METI is establishing default lifecycle greenhouse gas emissions values for ethanol produced from different feedstocks while tightening carbon reduction requirements.
In October 2025, the ministry revised the greenhouse gas emissions value for conventional gasoline upward to reflect higher emissions linked to fuel desulfurisation processes. At the same time, Japan increased its biofuel greenhouse gas reduction target to 60%.
Until now, Japan had recognised default lifecycle emissions values only for U.S. corn ethanol and Brazilian sugarcane ethanol, which are currently set at 36.86 grams of carbon dioxide equivalent per megajoule (gCO2eq/MJ) and 28.15 gCO2eq/MJ, respectively.
Under the latest proposal, Brazilian corn ethanol produced using biomass as an energy source would receive a default emissions value of 28.59 gCO2eq/MJ. The value rises to 40.4 gCO2eq/MJ when natural gas is used during production. METI has also indicated that qualifying Brazilian corn ethanol should be derived from second-crop corn cultivated after soybean harvests.
For Thai sugarcane ethanol, the ministry has proposed a default greenhouse gas emissions value of 28.26 gCO2eq/MJ, placing it among the lowest-carbon ethanol pathways under consideration and close to the emissions profile of Brazilian sugarcane ethanol.
Thai cassava ethanol showed a much wider emissions range depending on the energy source used. Ethanol produced with natural gas has been assigned a proposed value of 59.25 gCO2eq/MJ, while production using wood chips for energy would qualify for a significantly lower value of 20.9 gCO2eq/MJ.
The proposed benchmarks underscore the growing importance of feedstock selection and production methods in determining the carbon intensity of biofuels. They also reinforce the strong environmental credentials of sugarcane ethanol, which continues to rank among the most competitive low-emission renewable fuel options available to international markets.
The move forms part of Japan’s broader strategy to reduce emissions from the transportation sector while encouraging the use of sustainable biofuels that meet increasingly stringent climate and energy security objectives.
