I am by no means an expert on biodiesel. I have just been loosely following it. The methanol and lye are converted in the process to make the fuel. it is a reaction that makes it a combustible, freer flowing liquid. So they are used up in the conversion and the other parts converted to glycerin.
As for the glycerin... I think glycerin soap gets a premium because it is good stuff. While market saturation would drive prices down, there are plenty of uses for it. Face soap, hand soap, pet soap, car soap.. etc.. put some hemp in it and make glycerin hemp soap.... :-)
Do some searches on google for biodiesel and you will be up late reading about it, how to make it, by product uses, getting rid of foreign dependencies, cleaner air. I predict it is a natural evolution that will happen. Diesel engines are far more efficient, have a ton more torque and are even getting speedy with modifications.
Jeep is introducing a 2005 (this fall) Liberty with a CRD (common rail diesel) that (to quote) "has the fuel efficiency if an I4 (inline 4), the acceleration of a V-6 and the torque of a V8".
And a TDI VW Beetle gets 50 MPG.
I sure hope they come out with the Jeep Rescue. (600 ft/lbs torque Cummins turbo diesel in a 4 door full size SUV Jeep)