Can biodiesel be made using ethanol?
Yes, ethanol-based biodiesel, or ethyl esters, produce biodiesel with some properties, such as gel point temperature, that are superior to methyl esters. Ethanol also has the advantage that it is less toxic and safer to work with. Currently, the per gallon price for ethanol is about the same as for methanol. However, due to its higher molecular weight, the reaction requires about 45% more pounds of ethanol than for methanol. The advantage is that these extra pounds of ethanol go directly into additional biodiesel, so the value of the biodiesel can offset the additional cost of the ethanol. A disadvantage of using ethanol is that when the excess ethanol is recovered following the transesterification reaction, the alcohol will have collected any water that was present in the reaction. This water needs to be removed before the alcohol is reused and since ethanol forms an azeotrope with water, the removal process is more complicated than for methanol.
