While 5-10% biofuel blending is a mainstream fuel every drivers when they fill-up at the pump, higher blends of 20% and beyond are typically broken down by individual fleets or whole vehicle segments. This includes the aviation industry, which has taken incremental steps towards reducing global emissions for airlines (current 10% of U.S. annual emissions). A recent agreement was signed by the aviation industry to offset all new emissions after 2020 with carbon reclamation/credit purchases. While baggage carriers and other airport support vehicles can easily convert to CNG, electric, or other fuel sources, airplanes carry a unique challenge of adopting alternative fuels due to required energy density of fuel and storage. This inspired United Airlines, KLM, Lufthansa, and other airlines to begin test deployments of biofuel blends for select domestic and international flights.
To support this effort, NASA has also gotten involved on testing higher biofuel blends in commercial airplanes to measure the impact they have on engine turbine emissions. While current commercial flights are using 30% biofuel blends, NASA used a 50:50 volume blend of low-sulfur content Jet A fuel and a Camelina-based EFA biojet fuel. In these tests, key emissions were found to reduce by half (including VOCs and PM). While three years remain for emissions standards to be set for commercial airlines, these recent test deployments and discoveries offer key options for the aviation industry to reduce carbon emissions.