Friday, March 14, 2008

Driving on Waste Vegetable Oil (WVO)

As many of you may know, I drive a Grease Car. More specifically, the bulk of my fuel used in my daily 125 mile commute to and from KAXE comes from vegetable oil discarded from deep fat fryers. Thru information gathered from the Net, I've converted a 1991 VW Jetta diesel to burn any type of vegetable oil. A conversions consists of creating an entirely separate heated fuel system in addition to keeping the original fuel system as the car must be started and shut down on diesel otherwise the vegetable oil will congeal in the fuel lines.

Burning waste vegetable oil is a renewable, true carbon neutral fuel source and does not take productivity out of the food supply. Additionally, since it is a waste product, it is the ultimate in re-use of a high energy source destined for lesser use or landfills. The emissions from vegetable oil are lower in particulates than diesel and is 100% domestically produced.

For those that are into this stuff, I'll detail my layout with the hopes it will inspire others.

Tank: welded 14ga. mild steel, interior unpainted, exterior painted with galvanizing paint with a Krylon clear overcoat. This is the perfect excuse to buy that MIG welder you've always wanted.

Tank Heater: triple wall copper heated fuel pickup. This took a while to scrounge the pieces together but it works very well and threads into the steel tank.

Fuel Pump: Facet brand 4-6 psi pump.

Fuel Lines: HIH (Hose In Hose) for fuel delivery, HOH (Hose On Hose) for fuel return.

Temp Booster: diesel glowplug installed in a brass Tee.

Heated Fuel Filter: VW filter head from early diesels with a 120v silicone battery warmer wrapped around the filter and insulated. This requires a 120v inverter obviously but you've always wanted 120v power in your car anyway, right?

Fuel Switching Valves: 2 - 6 port Pollak valves, independently actuated to enable choice of fuel return to either the diesel or veg tank. This allows one to purge the system of veg oil before returning fuel to the diesel tank to prevent contamination. Beware when buying these on eBay as there as some counterfit valves that look identical but do not have the quality of the Pollak brand.

Injector Line Heaters: fiberglass wrapped nicrochrome wires. These are held onto the steel injection lines with self-fusing silicone tape.

Instrumentation: Veg Oil fuel gauge, oil temp, fuel pressure

To date, I've driven about 4,000 miles on vegetable oil and have been impressed with how well the system works. Cold weather performance has exceeded my expectations with being able to run at -30F on veg oil once the oil is warmed up. Fuel mileage is equivalent to diesel and at an average of 45 mpg for either fuel type. With diesel at $4 per gallon, I'm saving about $50 per week with the miles that I put on.

Common Questions:

Where do I get my oil from?
ARAMARK Food Services provides dining service to Bemidji State University and is providing me their oil. They have been very accomodating in this venture and I can't say enough good about the ARAMARK staff with their willingness to take some extra effort. It should be noted that ARAMARK is currently using Frymax Sun Supreme which is a non-hydrogenated sunflower oil that was specifically selected for healthier frying. Since it is non-hydrogenated, it also has wonderful low temperature characteristics for cold weather fuel use!

Does the exhaust smell like french fries?
Yes and no. There is a hint of delicious, peppery fried food in the exhaust but for the most part it smells like burning vegetable oil as you might have when drips fall on the stove.

How much did the conversion cost?
I've kept all my receipts and have been afraid to add them all up! However, I estimate that I have around $1000 in parts and equipment for filtering. So, my payback should be in far less than a year.

What do I have to do to the oil before I use it?
Only filter it. I use a 4 stage filtration process that starts with a paper filter used by restaraunts to coarse filter fryer oil. This gets the chunks out. From there I pump the oil thru a 20 micron whole house filter and then finish it by going thru polyester filtration socks at the 5 and 1 micron level. It take me about 4 hours to filter 50 gallons of oil. That works out to around $50 per hour for my labor!


Sam said...

Good luck with your vegoil. You might check your fuel pickup, I suspect you will end up with oil polymerizing on the copper and eventually peeling off and plugging your filter.


Dan Houg said...

Hi Sam-
While copper is known to polymerize veg oil, a large number of miles have been logged by people like Dana Linscott using copper, heated fuel pickups. To date, there is absolutely no evidence of polymerization on my system.

I do 2 things that might help this... 1) I mix some diesel in with the veg oil and there this has shown to greatly cut down on polymerization throughout the fuel system. 2) I make sure my fuel does not contain water via the "pan test". I suspect having suspended water in the fuel promotes all sorts of reactions.

Thanks for the comment!

cigs.excellent said...

Completely agree with Sam

Anonymous said...

Check this out. A centrifuge built for especially for cleaning up waste veggie oil. www.biofuelcentrifuge

AjSanteiro said...

Andrew in FL:

Have any drawings/plans of your set up? I'm involved in converting an old blue bird and am looking for every bit of advice I can get. Much appreciated.