Dr Anjan Ray, Director CSIR-Indian Institute of Petroleum, explains the importance of the flight and what has been achieved by the institute. Edited excerpts:

What does blending involve?

ATF burns at a certain rate, delivers a certain calorific value when it burns, gives a certain quality of air exhaust, it does not freeze at a temperature that a plane flies. It will not flash on the ground or catch fire when I am transferring it. So biofuel must be more or less the same density as ATF. It must keep the filters clean, it must not choke the filters of the engine when it is running and it must properly lubricate the engine. On every single parameter it has to be tested within the boundaries required. We do the testing ourselves as we have sophisticated facilities.

How do you simulate it going into an aviation engine?

We sent it to Canada. Back in 2013, Bombardier had run it on its PW engines. Bombardier had done tests. This plane was ideal as it had already used that engine . With an aircraft company that was comfortable with it and an airline company that was willing to take the bet, all the pieces fell into place.

How much more fuel will be needed?

It depends on the aircraft and fuel. If I take a Boeing 737 Delhi-Mumbai, it will take one-and-a-half tonnes per engine per hour whereas this one took only 430 litres for a 40-minute flight, plus some circling. It is about 1-2 per cent more energy-efficient than ATF. There is a feature called energy density — how much energy density you get per litre. Bio-jet is slightly more energy-dense.

Is it early days to make cost estimation?

You can do a back-of-the envelope estimation that 70 per cent of the cost of the bio-jet will come from feedstock. So, as long as you can produce the feedstock to scale, you can predict that bio-jet will be competitive.

How much more have you achieved as compared to the others?

Two things we have done which are remarkably different. Firstly, biofuel is blended 50-50 by the existing global processes as it does not contain aromatic compounds. Our process makes aromatic compounds. It allows you to meet existing standards without modifications. We could go 100 per cent with our fuel. It is just that the specifications today do not allow us to do that. Second, normally, jet-fuel is much more capital-intensive as you need two separate reactors. One takes the oxygen out of the vegetable oil and the other adjusts the properties. We used a single reactor so it is much less capital-intensive.

Related Topics
comment COMMENT NOW