Aviation industry prepares biofuels for take off

BusinessGreen.com: As vice president technology and environment at one of the world's largest developers of aviation engines, you must be well used to the charge that the sector is environmentally unsustainable and has not done enough to cut carbon emissions

Dr Alan H Epstein: It's true that aviation was the bad boy of the environment, but it now has one of the most coherent approaches to environmental issues. From the companies such as Pratt and Witney that make the equipment, to plane manufacturers such as Boeing and Airbus, to the airlines and airports, we have all got together. It is partly because we have realised the truth of Benjamin Franklin's rubric: "Gentlemen, we must all hang together or assuredly we shall all hang separately."

What is the aim of this coalition?

We have a plan. It is technically sound and it will get us to a place where emissions from aviation are no longer growing, and in fact start to come down. We can achieve that through new engine designs and carbon-neutral fuel, most likely in the form of biofuels. Boeing expects four to five per cent growth a year for the industry between now and 2050, so to stop emissions growing we need to take out five per cent a year. Between 1959 and 2009 the industry has improved fuel efficiency by 2.5 per cent a year, primarily through better engine design. We think we can continue that pace of improvement so the question is where do we get the other 2.5 per cent improvement from. The answer has to be lower-carbon fuel.

How do you deliver lower-carbon fuels?

It can be done in a number of ways. We have a picture in the office of a hydrogen engine that Pratt and Witney developed as part of a top-secret project called Project Suntan. Part of the way through the project, someone at Lockheed Martin realised it would not work for aircraft and gave the money for the research back to the government. The fact is, the energy density is too low, which means that the plane would have to be too heavy and you’d get too much drag. Some companies are now looking again at whether you could use hydrogen engines more widely, but you need a fuel with a high energy density. The US military has spent hundreds of thousands of dollars over the years on jet fuel research and it always comes back to kerosene. We need to make kerosene green and the way to do that is to make it from a carbon-free source. The best option is plants. Using a biofuel is effectively using solar power. In a way, you are charging the battery on the airplane with solar power.

But are biofuels really a sustainable and feasible alternative to kerosene?

As an engine company, we are focused on whether biofuel is technically feasible. All the research so far suggests that it is and the test flights done by companies such as Japan Airlines show it works. The focus is now on getting biofuel certified for use in existing aircraft. If we need to develop new aircraft to use this fuel, it will cost trillions of dollars – we need a drop in fuel. We want to certify a biofuel by 2011 and we have an agreement to share results with GE and Boeing – between us we make up 98 per cent of the engine market and we are working as a team on this to get the engines certified for using biofuel. We think that is a realistic timescale.

What types of biofuels are you looking at?

The most exciting development is Synthetic Paraffinic Kerosene (SPK). You basically take a vegetable oil and hydrogenate it in an existing refinery with catalysts. What comes out is an excellent fuel, in fact it is better than conventional fuel in terms of particulates and allows for a more efficient engine design that could improve fuel efficiency by a couple of percentage points. The flight we worked on with Japan Airlines used an SPK made from a mixture of Cannelina, or rape seed as you call it in the UK, jatropha and algae.

Critics have argued the environmental benefits of biofuels are overstated. Are they really delivering net carbon emission reductions?

The estimates I've seen are a 40 to 60 per cent reduction in full life cycle emissions compared to conventional fuel. But that is now – as we move to electric vehicles and better farming techniques, the life cycle emissions are bound to get lower.

The other criticism is that these fuels are unsustainable and will require too much land to develop. Is this justified?

Sustainable has many connotations, but it basically comes down to water, impact on land and soil and competition with land used to grow food. If you make the biofuel from soya beans, you get about 100 gallons per acre per year. That means that to make the 70 billion gallons of fuel the aviation industry uses each year, we need half the land area of North America, which is just not viable. But soya beans were not designed to make biofuel and we'd expect improvements in crops to increase yields by a factor of four or five. And then you have the developers of algae-based biofuels who say they can do 100 times better than soya beans.

Soya is 0.05 per cent efficient at turning sunlight into fuel, so to get a 100-times improvement. Algae needs to be five per cent efficient – that is entirely plausible with algae. At a yield of 10,000 gallons per acre per year, you only need an area the size of North Dakota. You could even see commercial algae plants combined with coal-fired power plants in the future and the carbon emissions used to enrich the growth of the algae.

But algae-based biofuels are still a long way from being developed on that kind of scale. Can anything be done within the next five years?

We can start with rape seed. Farmers tend to grow it every four to five years as part of crop rotation as it shares no common pests with other crops. In the US there is enough rape seed produced to generate aviation biofuel that would meet five per cent of US jet fuel consumption. There are also other options in the form of cellulosic biofuels made from wood chips and the like.

You paint an optimistic picture for the industry. What are the biggest barriers to realising this vision?

The biggest barrier is money. It is a capital-intensive business and the question is where the capital will come from. I'd argue that schemes that suck capital out of aviation suck the pace out of greening the industry. If you are going to have cap-and-trade or tax for aviation, the question is what happens to the money. I'd argue there should be a way of returning it to develop these fuels. The other issue is whether or not airlines will pay for more expensive biofuel. Our guess is some will. We are already finding that the biofuels are better in terms of particulates and as air quality regulations and carbon pricing comes in, more airlines will want to switch.