摘要：Biodiesel is a renewable diesel-fuel substitute with the advantages of reducing dependenceon foreign petroleum, mitigating greenhouse gas emissions, and improving urban air quality. Asestimated by Sheehan et al.(1998), biodiesel has the potential of reducing CO , particulate matter,2carbon monoxide, and sulfur oxide emissions by 78, 32, 35, and 8 percent respectively. Withthese advantages, biodiesel has the potential of supplanting petroleum diesel as an engine fuel. This is true not only for pure 100% biodiesel fuel, called neat biodiesel, but is also true for what iscalled blend biodiesel fuels. For economic and engine-compatibility reasons, blend biodiesel is amix (blend) of biodiesel with petroleum diesel. Generally this blend is 20% biodiesel and 80%petroleum diesel (B-20) (Brown,1997). Such substitution is consistent with Federal regulatorypolicies resulting from the implementation of the Clean Air Act Amendments of 1990 whichpromote cleaner fuels and the Energy Policy Act (EPACT) of 1992 which encourage the use ofalternative fuels as a means to reduce petroleum imports.
