You have no idea how biodiesel is made, do you? Alcohol and a catalyst (lye is the simplest) are needed.
A typical acre of cropland will produce 5 times as much corn ethanol as rapeseed biodiesel.
LOL, you do not distill rapeseed, you press it and the little oils run out screaming that hurt. LOL, do you think everything involves a high engery distrillary. Simple process: http://www.angelfire.com/mi3/gmpr/biodiesel1.htm