Getting the Lead Out of Aviation Fuels
Help is on the way with the problem of lead in aviation fuel, and it’s coming from the federal government, private enterprise, and pond scum. It’s just in time, because the U.S. Environmental Protection Agency has formally begun the regulatory process required by the Clean Air Act that may ultimately result in mandating the transition to unleaded aviation gasoline.
News of an advance notice of proposed rulemaking (ANPR) was reported in a recent EAA News installment. If successful, the change would be good news for everyone including users of general aviation engines, light-sport engines such as the Rotax 912 series, and anyone who needs a lead-free and alcohol-free fuel to keep flying safely. Calculations indicate the use of 100LL aviation gasoline is responsible for 500 to 600 tons of lead emissions each year in the United States, or about half of the nation’s total.
The FAA is planning to spend $10 million over the next five years for aviation gasoline development – $2 million in 2011 that will include ground testing of candidate unleaded fuels at the agency’s Atlantic City technical center. One of the leading contenders is Swift Fuel, a synthetic form of gasoline made from sorghum that was demonstrated at the 2010 Sun ’n Fun Fly-In at Lakeland, Florida, in a twin-engine Piper Seminole. Embry-Riddle is already testing Swift Fuel in its fleet of training aircraft which includes more than 40 Cessna 172s. The fuel doesn’t require any additives or stabilizers, and the company claims it could be dropped in replacement for today’s 100LL fuel.
While biomass fuels are renewable, their net effect can be negative if cropland or forests are taken over for fuel production. Ultimately a better solution may be found with the help of pond scum, or algae. The U.S. Navy has contracted for the use of biodiesel in the F/A-18 Super Hornet, and Japan Airlines has also tested biodiesel with success. The leader in algae biofuels is Aurora Biofuels. The company has created strains of algae it says can produce two gallons of oil per acre, per day, at a cost of about $2 a gallon. The ponds can use seawater and can be placed on nonarable land. Someday in the future we may be flying on pond scum.