Good story here about a soybean powered car - both about the power of engaging kids' minds and about the possibility of alternative fuels......heavy on the former, not very descriptive of the latter....
I believe they focus on the fact that it is not the best students doing this because that is the most interesting part. The other part, the fact that it is a soybean (biodiesel) powered car is not so exciting because it is a stock TDI engine from a VW, with some unmentioned generator, and an ACPropulsion 200hp electric drive system. These systems are fairly off-the-shelf items and required some custom mounting, but the story doesn't mention what engineering feats these students have accomplished most likely because they didn't do anything to speak of.
Since biodiesel is a drop-in replacement in a diesel engine, I can only guess the writer meant that either: 1) the car is a biodiesel-electric hybrid, or 2) it runs on straight vegetable oil, which is *not* the same as biodiesel and requires a dual-tank system.
Good catch. I only saw a sticker on the car in another photo that said "biodiesel" It may be a dual-tank setup, which would be interesting, but because there is no mention of it, I am lead do believe that it is a vegtable oil/diesel mix, like b80 or something. As for the biodiesel-electric hybrid, It seems to be a series hybrid, having no appricable electric storage by virtue of the fact that it wouldn't have the space for any batteries of sufficient size in such a small car.
Sorry to belabor this, but B80 is not an oil/diesel mix, it is a biodiesel/diesel mixture with an 80:20 ratio and is correctly called a "biodiesel blend." Biodiesel is a fatty acid methyl ester that can be *made* from vegetable oil, but is not the same thing. Pure biodiesel is also called B100. A more typical blend is B20. When you put vegetable oil in a diesel engine, it is not blended in one tank, but is introduced through a separate tank so that the engine can be started and stopped on diesel, and the fuel lines are left filled with diesel. Vegetable oil is too viscous to leave in the fuel lines.
Out of curiosity, you wouldn't happen to know how the diesel hydrocarbon chains are "made" from veg oil do you? Asside from viscosity and ignition temperatures, I'm curious what other differences, changes in chemical structure, and if there are any waste products created by the process. I am aware that there is a home-brew system of adding lye and ethanol, mixing thuroughly, then letting a gelatinous settle to the top. Am I correct here and if so, do you know of any use for this gelatin? I saw this process on a show called Trucks, but they never said what they did with the gelatin.
To oversimplify, oil plus alcohol (usually methanol) makes biodiesel and glycerine. The lye acts as a catalyst. A vegetable oil molecule is made up of three esters attached to a glycerine backbone. The esters get separated and "transesterify" -- the glycerine gets replaced with the alcohol. Use too much catalyst and you get soap. The glycerine has various uses, but as biodiesel production increases, the market for glycerine is getting glutted. You can burn it but since fuel is pretty much the lowest-value chemical you can make, it is not your best choice. Bottom line is, biodiesel is easy to make but not easy to make well or profitably. Lots of people can pick up a saxophone and make noise too, but few are going to sound like Charlie Parker.
Off-the-shelf install
