In recent weeks, there has been a lot of discussion across the country about Ethanol Blended Fuel (E20 Petrol). To reduce petrol imports and dependency, the government has started blending 20% ethanol with petrol, which is now available at many fuel stations across India. However, several vehicle owners have complained about reduced mileage and performance. Now, the government is preparing to blend Isobutanol with diesel.
During a recent event organised by Praj Industries in Pune, Union Minister for Road Transport and Highways, Nitin Gadkari, said, “Ethanol is just the beginning for us; it is not the end. I especially thank Praj Industries and ARAI for starting work on Isobutanol after ethanol. They are currently experimenting by blending 10% Isobutanol with diesel. Additionally, in collaboration with Kirloskar, they have developed an engine that can run entirely on 100% Isobutanol. Isobutanol is an alternative biofuel.”
Nitin Gadkari further added, “Isobutanol can become an excellent alternative to diesel. In India, diesel usage is about two and a half to three times higher than petrol. Pollution is a major concern due to both petrol and diesel. In the coming years, Isobutanol could prove to be a boon for the country. Once research, trials, and standards are finalised, and the Petroleum Ministry approves it, the market for Isobutanol will expand significantly.”
What is Isobutanol?
Isobutanol is a colourless, flammable organic liquid belonging to the alcohol group, with a chemical formula of C₄H₁₀O. It is widely used as a solvent in paints and coatings. Due to its high energy density and octane rating, it is also used as a fuel additive. Isobutanol can be produced from petroleum or biomass using a process called propylene carbonylation.
Use of Isobutanol in Diesel
Fuel Blending – Isobutanol can be blended with diesel to improve fuel efficiency and reduce emissions.
Clean-Burning Fuel – Since it contains less sulphur and harmful elements, it ensures clean combustion in diesel engines.
Reduction in Greenhouse Gases – Using Isobutanol-blended diesel reduces emissions of CO₂ and particulate matter.
Engine Compatibility – Research shows that Isobutanol-diesel blends can be used in existing diesel engines without major modifications.
Better Performance – It helps maintain engine performance and slightly reduces overall fuel consumption.
Also Read: PIL Filed in Supreme Court Over Decision to Mix Ethanol in Petrol, Petitioner Raises Key Demands
Current Research and Trials
Research on Isobutanol-diesel blending is still ongoing. Experts believe that future diesel engines may follow the flex-fuel concept and could potentially run entirely on Isobutanol.
According to a Society of Automotive Engineers (SAE) research report, blending 5% and 10% Isobutanol in a 4-stroke single-cylinder diesel engine showed:
- Improved Brake Thermal Efficiency (BTE)
- Better Brake Specific Fuel Consumption (BSFC), meaning less fuel used per unit of energy
- Significant reduction in carbon emissions and smoke opacity
- Slight decrease in NOₓ emissions
However, the final approval for blending Isobutanol in diesel is still pending. Trials are underway, and the proposal will be sent to the Petroleum Ministry after successful testing and standardisation.
Diesel Consumption in India
According to the Petroleum Planning and Analysis Cell (PPAC):
- Diesel contributes around 40% of India’s total crude oil consumption.
- In 2024-25, diesel consumption is expected to rise by 2%, reaching 91.4 million tonnes.
- For 2025-26, diesel demand is projected to grow by 3%, reaching 94.1 million tonnes.