Earlier this week, EPA expanded the definition of heating oil under the renewable fuel standards (RFS). This rule comes under EISA's "additional renewable fuel" definition, which is fuel produced from renewable biomass that is used to replace or reduce the quantity of fossil fuel present in home heating oil or jet fuel. The prior definition of heating oil, under the RFS, was fuel that met the specifications of No. 1 or No. 2 heating oil, or being a non-petroleum diesel blend. According to code, non-petroleum diesel is a fuel with at least 80 percent mono-alkyl esters of long-chain fatty acids from vegetable oils or animal fats. The new definition makes it easier for blended advanced biofuels such as bioheat, a mixture of biodiesel and hea...