Explained: What is biojet fuel, which powered the IAF aircraft mentioned by PM Modi in his Mann ki Baat?

According to a government release, the aircraft was flight tested and its performance was validated at Chandigarh Air Base prior to undertaking the operational flight to Leh. (Twitter/Indian Air Force)

In his monthly Mann ki Baat radio address, Prime Minister Narendra Modi on Sunday (February 23) hailed the use of biofuel in an Indian Air Force transport aircraft, saying such innovations would bring down carbon emissions and lower the nation’s oil import bill.

History was made, the PM said, when the IAF’s An-32 aircraft using a 10% blend of Indian biojet fuel took off from Leh’s Kushok Bakula Rimpoche airport on January 31. This was the first time that this mix was used in both engines of an aircraft, he said.

Biojet fuel

Biojet fuel, the PM said, is prepared from “non-edible tree borne oil”, and is procured from various tribal areas of India.

This fuel is made from Jatropha oil sourced from Chattisgarh Biodiesel Development Authority (CBDA) and then processed at CSIR-IIP, Dehradun.

Leh flight

According to a government release, the aircraft was flight tested and its performance was validated at Chandigarh Air Base prior to undertaking the operational flight to Leh.

Leh is at an altitude of 10,682 ft above mean sea level, and is among the world’s highest and most difficult operational airfields. Even during clear weather, operating an aircraft at Leh is a challenge, given the reduced power output of the engines in the rarefied atmosphere, turbulent winds, and proximity of the mountains.

Why it matters

Evaluating the performance of biojet fuel under conditions prevalent in Leh was considered extremely important from an operational perspective.

The success of the flight that the Prime Minister referred to validated the capability of the aircraft’s engines to operate smoothly with biojet fuel at the extremities of the operational envelope.

The tests were conducted by a team comprising test pilots from the Aircraft and Systems Testing Establishment (ASTE), Bengaluru and pilots from the operational squadrons, the government said.

The successful test flight also demonstrated the IAF’s capability to absorb newer technology, while sponsoring indigenisation.

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The technology

The technology to produce this fuel was developed by CSIR-IIP in 2013, but it could not be tested and certified for commercial use immediately.

In 2018, the IAF sponsored this project and channelized its human and material resources for the complete range of fuel testing.

On July 27 that year, addressing the CII-SIDM seminar on promoting indigenised technologies, then Air Chief Marshal BS Dhanoa, announced IAF’s intention to promote biojet fuels.

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On December 17, 2018, ASTE pilots and engineers flew India’s first military flight using blended biojet fuel on the An-32 transport aircraft. The project was a combined effort of IAF, DRDO, Directorate General Aeronautical Quality Assurance (DGAQA) and CSIR-Indian Institute of Petroleum.