They get their fuel from the used oil tank behind restaurants.
All processing of incoming oil takes place right on the bus, mostly while it's in motion. That means heating, water separation and filtration. They get about 10 mpg on veggie oil, which is about the same as they do on diesel.
This bus is a VEGGIE DIESEL bus, that can burn straight vegetable oil, as well as regular diesel or biodiesel.
It's a "two-tank" system, which means the bus has a small tank of biodiesel (or diesel) to start the engine, and then they switch to straight vegetable oil when the engine is hot.
For the uninitiated, Biodiesel is veggie oil that's been subjected to a chemical process so it's thin and runny (lower viscosity) all the time and can be run in unmodified diesel engines. This bus runs on straight veggie oil, no reaction needed. It only requires biodiesel or diesel fuel except for starting and shutting down the engine.
Check out [www.biotour.org biotour.org's website] for the history of how their methods have evolved.
Here Ethan Burke shows the pre-filters.
In another side compartment is the collection hose. They park next to the restaurant's waste tank, dip the end of their collection hose into the top, and start pumping oil into their storaage tanks.
They dip a piece of cardboard into the oil and do other connoisseur stuff to see if they want that restaurant's oil or not.
They don't want the oil at the bottom of the waste tank because that's where water and dirt settles. Their collection hose has a screen on the end to filter out bits of french fries, dead leaves, etc.
Step 1: Storage Tanks
The incoming oil goes here. The transfer pump can empty either of the side tanks into the center tank.
The center tank is heated.