merigayle, I'd think twice before leaping onto biofuel. Although I applaud using a waste product for fuel, your source of fuel may dry up as gasoline prices rise, (and they will soon according to stats). Furthermore certain goverment bean counters are trying to figure out how to tax it as well. They consider using it for road travel an avoidance of tax. Consider too the cost, time, and effort of purifying and removing the glycerine, the issue of solidification in cool weather, possible cleaning or repairs to the fuel system, and the increased carcinogenic nature of any Diesel exhaust (including biodiesel).
You may have political, environmental or economic factors that I'm not aware of, such as owning a restaurant . In that case you must follow your heart. Just take the above as a kind of brotherly advice.
