Whats the difference between ethanol and biodiesel?
Ethanol, which is made from fermenting starch crops (typically corn or cellulosic biomass such as grasses or agricultural waste), is intended for use in gasoline engines, while biodiesel is intended for diesel engines. What’s referred to as “ethanol” is a blend of 85% ethanol and 15% gasoline called E85, and it can only be used in flex-fuel vehicles designed to handle the fuel. Ethanol contains about 25% less energy than gas and therefore results in diminished fuel economy. Ethanol is frequently used as an additive to help reduce smog-forming emissions; gasoline in many metro areas in Texas contains 10% ethanol. Pure biodiesel contains about 10% less energy than petroleum diesel. However, a Minnesota Department of Agriculture study found that ethanol returned 34% more energy than it took to produce it, while biodiesel returned 220% more – that’s compared to gasoline’s -19.5% and diesel’s -15.7%.
