A look at possible alternative jet fuels

A look at possible alternative jet fuels

By THE ASSOCIATED PRESS

BIODIESEL: Researchers say this fuel made from soybeans and other products could be used in airplanes, but the challenges include its high freezing point and the difficulty in producing enough for widespread airplane consumption. Some say it's more likely biodiesel will be blended with more traditional fuels.

LIQUID HYDROGEN: Hydrogen takes up more space than jet fuel, and must be kept very cold. That means airplanes would have to be redesigned to accommodate it.

SYNTHETICS: These are made by turning fuels such as coal or oil shale into a liquid that can act like traditional jet fuel. Synthetics could be a lower-cost alternative, but for now, they require more resources to produce than traditional jet fuel.