Ethanol blending in diesel fails flash-point test: Govt
Ethanol-blended diesel failed required safety specifications because the addition of ethanol sharply lowered the fuel's flash point, Minister of State for Petroleum and Natural Gas Suresh Gopi said on Monday, effectively ruling out the fuel for wider use unless the technical issue is resolved.
Public-sector oil marketing companies conducted scientific evaluations of ethanol blending with diesel through their research and development centres, in collaboration with accredited laboratories and automobile manufacturers, Gopi said in a written reply to Parliament.
The tests found that ethanol-blended diesel did not meet the required diesel flash-point specification because the flash point fell sharply in the presence of ethanol, he said.
"Scientific evaluations on blending of ethanol with diesel have been undertaken by Public Sector Oil Marketing Companies (OMCs) through their respective R&D centres in collaboration with accredited laboratories and automobile manufacturers. It was observed that ethanol blended diesel was not meeting diesel flash point as its flash point lowered drastically due to the presence of ethanol," he said.
The finding comes as India seeks to expand the use of ethanol as a transport fuel and explore new outlets for rising domestic production. The government has so far focused its ethanol blending programme on petrol and has set a target of 20 per cent blending.
Asked about blending isobutanol in diesel, the minister said, "Isobutanol is presently not being blended with diesel."
Gopi said no decision has been taken to raise ethanol blending in petrol beyond 20 per cent. Any future increase would be considered only after detailed scientific and technical studies and consultations with automobile manufacturers, oil marketing companies and research institutions.
State-run oil marketing companies floated their first tender in September 2025 to procure about 10.5 billion litres of ethanol for the 2025-26 ethanol supply year. They received offers for nearly 17.6 billion litres, about 68 per cent more than the quantity sought, and have allocated 10.485 billion litres to 378 registered suppliers.
The government is also examining ethanol as a potential cooking fuel, which could help reduce India's dependence on imported liquefied petroleum gas while making use of surplus domestic ethanol production capacity.
"The use of ethanol as a cooking fuel may emerge as the potential biofuel alternative to fossil fuel based cooking solution which may help in reduction of LPG import dependence and provide clean cooking solution. This may also enable effective utilization of surplus ethanol production capacity in the country," he said. "The initiative is aligned with the Government's broader objective of promoting cleaner and alternative cooking fuel options."
The LPG Equipment Research Centre, a joint venture of Indian Oil Corp, Hindustan Petroleum Corp and Bharat Petroleum Corp, along with public-sector oil marketing companies, is working on developing ethanol-based clean cooking alternatives, Gopi said.
The government has introduced several measures to support domestic ethanol production, including interest-subvention schemes, support for cooperative sugar mills to convert existing sugarcane-based distilleries into multi-feedstock plants, and long-term offtake agreements between oil marketing companies and dedicated ethanol producers.
