Development of sustainable alternative jet fuels

Innovation — 05.09.18 BY Jill Stockbridge

A background to biojet fuel

While people may think of biojet fuel as a finished product, the pure ‘bio’ part goes through a blending process with regular jet fuel in varying quantities to create the product being sold today. Daniel Coetzer is CEO of Valcora, a fuelling company supplying jet fuel to airports around the world. The company has moved into biojet fuel supply, investing in mixing facilities and storage tanks. He explained their role: “We buy biofuels from different producers and distribute it to the airports. The amount of biofuel that can be added ranges from one to 20 per cent. Most aircraft manufacturers have approved a range from one per cent to 10 per cent. They are confident that you can put that amount in an aircraft engine and it will work. Now the development starts to enable the use higher percentages.”

SAJF is supplied to a number of global airports, including Los Angeles, Oslo, Bergen, Stockholm and Geneva, which recently announced that all fuel sold would now include one per cent biojet fuel. Brisbane also plans to incorporate an SAJF blend into their normal fuel supply this year.

Testing has been extensive and the industry, including OEMs and engine and APU manufacturers, has concluded that safety and performance are not affected by the use of biojet fuel. No modifications are required to the aircraft and there is no need for recertification or additional validation.

David Coleal, Chair of GAMA’s Environment Committee and President, Bombardier Business Aircraft, said: “SAJF are safe. They have been approved through a rigorous testing process, and have the same qualities and characteristics as Jet A and Jet A-1 fuel. This means aircraft perform the same under all conditions – you don’t have to fly differently. But challenges remain: limited production, lack of awareness, and challenges of infrastructure and economics combine to impede widespread adoption.”


But that limited production is a major issue. Coetzer said: “I think that before we can go over the 10 per cent mix, to the 20 or 30 per cent mark, the production of the biojet fuel will have to be boosted. There is not enough available. There are virtually just three refineries currently, although other facilities are being developed.

“We also have to look at the balance between the amount of waste required for the amount of fuel produced. We are going to run out of waste before we have the level of fuel we need. So new technology will have to be developed in order to create biofuels from something that is really waste for us,” he added.

Biofuel is created from a number of different sources, or feedstocks, including cooking oil, plant oils, solid municipal waste, waste gases, sugars, purpose-grown biomass, and agricultural residues. Biojet fuel is more difficult and expensive to make than biodiesel used in road transport due the high performance demands.

Karl W Feilder, CEO Neutral Fuels LLC, explained: “The chemistry is pretty straightforward. A hydrocarbon or biofuel’s molecule is a essentially a string of carbon atoms, with hydrogens on either side. In the case of biofuels, there is an added oxygen atom in the molecule, which acts to improve the combustion. As the carbon chains get longer, the fuel becomes more sensitive to cold weather. So by the time you’ve got up to 20 carbons in the chain, you have a fuel that is effectively solid at room temperature. As you get down to 10, eight or even six carbons in the chain you have something that is almost gas at room temperature. Somewhere in between is the length of the carbon chain for an aviation fuel that has to perform at 40,000ft where it is cold. With trucks, buses and transport at ground level you don’t have to deal with those type of temperatures in many countries.”


Feedstock viability

Coezter described the challenges. “To progress we need to find a feedstock supply that is sustainable, not environmentally damaging in other ways, and hopefully reduces waste. It should not have any impact on other areas, such as feedstock that is also food. Maize is one of the best-balanced feedstocks for revenue. The amount of maize you put in, compared to the amount of fuel you get out is very good. But morally, you don’t want to do that.

“One of our criteria as a company is that we will not buy from any supplier that uses food products as feedstock – certainly not any food product that could be eaten by somebody. If we were to live in a world where there is no hunger and no starvation, then OK, but until that day, it is too much of a luxury to use food as fuel for jets,” he added.

There are other issues with potential feedstocks. Palm oil is a very effective feedstock, but its cultivation for food has had huge environmental impact, with the clearance of rainforests and the destruction of habitats of rare fauna and flora.

Coetzer continued: “There is an algae project in Spain for producing vehicle fuel, which is interesting, but you again have question of quality and quantity. For so many tonnes of algae you got 10 drops of fuel. Then they improved the quantity of fuel from the algae, but that reduced the quality.

“It is really complicated and there are projects worldwide going on to develop new solutions. It is a balancing act, a complete tightrope, but it is a way forward. However, if the demand is there, then the technology will be developed. Somebody has to start the investment,” he added.

As the demand and acceptance increases across the world, both new and existing producers will be able to attract more investment. Already some of the largest energy companies, particularly BP and Total, are participating, resulting in the potential growth of the alternative fuel industry.

Tom Parson – Biojet commercial development manager, Air BP, explained their approach. “There is a variety of feedstocks that can be used for aviation biofuels. Since 2014 we have been supplying BP biojet, produced from recycled cooking oil, to a number of Swedish and Norwegian airports.

“In November 2016, Air BP and BP Ventures announced an investment of $30 million in biojet producer Fulcrum BioEnergy. Fulcrum has developed and demonstrated a proprietary process for producing biojet from municipal solid waste. The first plant, which is currently under construction in Reno, Nevada, will convert municipal solid waste feedstock into a low-carbon, renewable transportation fuel. BP has secured a 10-year offtake agreement with Fulcrum for 50 million US gallons per year from their plants under development across North America. Air BP is Fulcrum’s preferred supply chain partner and will distribute and supply this biojet into aircraft at key hubs across North America.

“Air BP aspires to be the leading supporter of the aviation industry’s low carbon objectives through reducing the carbon footprint of our own operations, securing access to advantaged biojet and offering a range of lower carbon technical services and operations solutions to grow with the market, including our presence at airports,” he added.


And the cost

Biojet fuel is, and certainly will be for the near future, more expensive. Coetzer agreed: “It is much more expensive. In a one per cent blend that is not such a big deal, but when you get to 10 per cent, it is a big difference. It is expensive to make and it more than doubles the cost of the fuel. It can make it up to four times more expensive, depending on the blending. But there is no other way around it at this point.”

There is currently no economic incentive to use biojet fuel, but there are benefits. Biojet fuels offer lower emissions and a slight gain in efficiency with many missions, but main incentive is the long-term benefit to the environment.

Coleal said: “This initiative is not only about fuels; it reflects our sector’s overall commitment to climate change. Even when considering the emissions produced in the supply chain of these inputs, their carbon lifecycle emissions are substantially less than compared to those of fossil fuels.”

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