Overview of Biofuels for Aviation

Aviation is a significant contributor of the worlds economy, and especially in Norway, it is a major transportation method for people and goods. The role of aviation is expected to increase in the future and with it the fuel demand and the environmental impact. The increased CO2 emissions are of major concern, thus being recommended to look into emission-reducing measures. Today, the aviation sector uses petroleum derived liquid fuels. Therefore, environmental impacts, security of supply and oil depletion are issues of concern. A number of potential alternative fuels and fuel blendings may be considered for aviation. The most likely alternative fuels for aviation are those with similar characteristics to conventional jet fuel. These are by definition "drop-in" fuels, which meet the oil-derived kerosene specifications. Today, there are two biofuel types certified for aviation, both in maximum 50 % blends with conventional Jet A/A-1. One of these is hydrotreated vegetable oil (HVO) derived from oil seed plants. This type of biofuel is commercially available and in small quantities is already in use. The other type, Fischer-Tropsch (F-T) kerosene derived from lignocellulosic materials is to be expected on the market within 5-10 years. The life-cycle benefits of a HVO fuel are very sensitive to biomass feedstock as it needs oil seed crops. However, the fuel itself is cheaper than the other alternatives, and is expected to be competitive with aviation kerosene when subsidized. The F-T fuel is more expensive, but its feedstock is cheaper and it has a better environmental profile.