The measure would tax ethanol at 8 cents a gallon at the wholesale level. Current state law includes more than one tax rate for ethanol, depending on how much of the grain-based fuel is blended with regular gasoline.
Rounds, a Republican, is a strong supporter of the ethanol industry, which lobbied the legislature for passage of the bill.
Industry officials believe an eventual law would promote the usage of so-called blender pumps, which allow a motorist to select among various blends of ethanol and regular gasoline to pump into a vehicle.