Diesel is more widely consumed than petrol, mainly due to its widespread use in commercial transportation and industrial and agricultural sectors.
Several steps have been taken by the government in recent years to reduce the country’s oil import bill. This includes electrification, blending ethanol with petrol and focusing on finding new oil sources within the country. The next goal is to reduce diesel consumption through isobutanol blending. For this, there is a plan to start a comprehensive trial in the second quarter of financial year 2027.
2% isobutanol diesel blending
Information about the 2% isobutanol diesel blending trials was recently provided by Girish Wagh, MD and CEO of Tata Motors. These trials will begin from the second quarter of FY 2027. the government has A high level task force was formed for this pilot project.Which includes various stakeholders like OEMs, testing agencies and oil marketing companies. For the trials, Tata Motors will supply isobutanol blended diesel from BPCL.
Even before these trials began, trials of isobutanol diesel blending had been underway for several years. For context, Bharat Petroleum has been testing this blended fuel for the last two years. One of these tests involved stationary Cummins engines, which were tested for a period of three months. Bharat Petroleum will now conduct more extensive testing, It covers about 33 different types of vehicles used in the country..
Other institutions such as the Automotive Research Association of India (ARAI) and the Council of Scientific and Industrial Research have also been involved in testing isobutanol diesel fuel. going forward, ARAI to launch 10-month technical assessment program In collaboration with Praj Industries. The latter is a leading provider of biofuel technology solutions.
ARAI’s main objective for this test is Find out if isobutanol can serve as a seamless diesel blend In real world situations. By involving multiple stakeholders, including commercial vehicle manufacturers and oil marketing companies, the feasibility of isobutanol for diesel blending can be assessed in a more practical and realistic manner. This approach will help in streamlining different approaches and will also help in timely identifying and fixing the issues.
Why not just use ethanol diesel blend?
Researchers have tried blending ethanol and diesel, but their different chemical structures do not allow proper mixing. Specialized additives could make this work, but these would be expensive and non-renewable. Standard diesel has an oily consistency, which does not allow it to mix with ethanol. Isobutanol is a four-carbon alcohol and has characteristics similar to diesel.
Another issue with ethanol diesel blending is the significant difference in the flashpoints of the two fuels. Ethanol has a flashpoint of 12-13 °C, while diesel has a higher flashpoint of around 35 °C. This difference presents challenges in terms of fire risk and safe storage and transportation. Isobutanol is a very close match with a flashpoint of 27–30 °C.
Benefits of Isobutanol-Diesel
Apart from reducing diesel consumption Isobutanol-diesel mixture will also help in reducing emissions. The existing storage and transportation infrastructure can easily sustain isobutanol-diesel blended fuel without requiring any major modifications. Tests conducted by Praj Industries have shown that isobutanol remains stable for more than 40 days even at concentrations as high as 10%.
2% blending is targeted, unlikely to be a major issue. The impact on fuel efficiency will also be negligible. Tests with 5% isobutanol showed Approximately 1-2% loss in mileage. This will be even lower with a 2% isobutanol-diesel blend. The 2% isobutanol-diesel blend is also unlikely to affect vehicle performance.