Editor’s Introductory Note: The recent spike in fuel prices prompted me to re-post this practical 2010 article from the SurvivalBlog archives. – JWR
Although I live in a rural setting, my current employment depends on being able to reliably commute about 45 minutes each way to the state capital.
Watching the shutdown and gradual restoration of the Colonial pipeline serving the southeast US in teh aftermath of Hurricane Katrina was a sobering experience. Fuel prices spiked to record levels and many stations were not able to re-supply for weeks because of the lack of sufficient movement in the pipeline.
It was at that point several years ago that I began researching alternative methods of driving moderate distances of up to 100 miles a day in the event that conventional methods of fuel supply (i.e., the infrastructure of fill-up stations along with the pipeplines supplying them) should become unreliable.
I wanted to have an alternative method of propelling a vehicle down the road that did not depend so heavily on the oil companies and the conventional petroleum fuel distribution network.
From my educational background as an electrical engineer, electric vehicles were (and are) indeed intriguing. However, the primary issue then (and now) was battery technology. Today’s batteries are still too heavy and expensive to match the energy density of a 5-gallon can of gasoline. That’s not to say that electric vehicles may not be a viable option in the future. Perhaps the Tesla Model S will really live up to its hype someday. But there was no such thing as even a Tesla Roadster at the time I began my research, so I looked elsewhere.
Compressed Natural Gas (CNG) has been further developed and marketed and commercially available vehicles such as the Honda Civic GX have been sold that can run a couple hundred miles on a tank. However, the tanks are very high pressure, and lacking my own natural gas well, I would still be beholden to an even scantier distribution network.
Distilling my own ethanol for a flex fuel vehicle was another possibility, but that seemed to require large amounts of feedstock such as sugar. Producing ethanol at the required purity appeared to be a complex task requiring significant amounts of energy.
Finally, I stumbled upon the topic of running diesel vehicles on fuel derived from used cooking oil. (Waste Vegetable Oil or WVO.) There are two broad categories here:
(1) Making BioDiesel which has characteristics similar to the #2 diesel sold at the pump. This requires a chemical transformation of the oil. The procedures for accomplishing this reaction involve fairly toxic and explosive substances. Methanol (or racing fuel, itself a petroleum product) is required as part of the reaction. However, the final biodiesel product is relatively non-toxic and non-explosive. It can be burned in many diesel vehicles with varying degrees of success. The main advantage to making biodiesel is that no vehicular modification is normally needed. The disadvantage for me was the need to purchase toxic reagants and dispose of the significant amounts of waste glycerin which is left over at the end.
(2) Modifying a diesel vehicle so that it can burn waste vegetable oil (WVO) directly. WVO has a much higher viscosity than #2 Diesel. It must be heated to somewhere in the neighborhood of 150 degrees before it will spray properly through the nozzles of a diesel motor injector. It is possible to run WVO through a diesel engine at lower temperatures, but the lower the temperature, the more damage is done to the engine. One big advantage to burning WVO is that no additional chemical ingredients must be purchased and there is not any waste product left over from chemical processing. Nearly 100% of the feedstock is used up.
I decided to pursue option #2, burning WVO. Further research showed that the best method for all-climate operation was to install a second tank in the vehicle exclusively for WVO. To heat the WVO, a system of heat exchangers is fed coolant from the vehicle’s radiator, which coincidentally has just about the right amount of heat once the vehicle is warmed up to operating temperature.
The next decision: which vehicle to purchase? I did not want to experiment on a new, expensive car or truck. From reading on the web, I decided on a 1985 Mercedes 300D with about 135,000 miles that I found in the local paper for $3,000. It ran well and seemed to have good compression. The 1985 300D engine was the last of the Mercedes diesel engine to use a cast iron head. The later aluminum heads were prone to cracking in some cases. All in all, the consensus on the web considered it a good candidate for a WVO conversion.
After that: should I purchase a kit or try to assemble something myself? Since I wanted to get going relatively quickly, I decided to purchase a kit marketed by Frybrid, a Seattle-based company with a reputation for quality products. The kit contained a second tank with a heated oil pickup, to be mounted in the trunk. Aluminum tube inside 5/8″ heater hose carries the oil up to the engine compartment where it passes through a coolant-heated filter and final heat exchanger. A set of valves controls the switching of supply and return lines between the two fuel systems.
The system operation has manual or auto modes. In auto mode, a temperature sensor closes when the coolant is up to temperature. This switches the supply and return valves and the monitor light changes from red to green, indicating transition from #2 diesel to WVO power. It was quite a thrill to see that green light go on for the first time! Almost as much fun as the first water pumped from my well with non-grid power!
Over the last couple years, I’ve put well over 2,000 gallons of WVO through the system. There is a small Chinese restaurant near my work which provides me 15 gallons of WVO a week – just about enough for my commuting needs. The fuel does need to be carefully filtered and any water removed. I use a plastic 55-gal barrel with a couple of holes in the top for blue-jeans filters. A stock tank heater and hand pump complete my fuel processing. This has worked well for me so far. The heater causes water and other impurities to settle to the bottom of the barrel. The pump pickup is above this layer.
Even during the winter, my old 300D is up to 80C in about 3-to-4 miles of 55 mph driving and I can switch over to WVO. What were the costs involved? About $1,800 for the kit, plus I paid a buddy of mine $500 to help install it. With the amount of driving I do, it paid for itself in about 15 months. When full, my WVO tank is good for over 500 miles in normal conditions. I pay my federal road tax quarterly and my state road tax monthly, so using WVO costs me about 40 cents/gallon. The Chinese place won’t let me pay for it. The vegoil filter element lasts from 5,000 to 10,000 miles.
Am I still dependent on the oil companies? Yes, but to a much lesser degree. I only need to run on diesel fuel when starting up (while the engine is warming up) and just before shutting down. I can store a couple of 55-gallondrums of diesel fuel which will now take me much further than they would have previously.
Is running WVO for everyone? No. There’s not enough WVO to supply more than a few percent of America’s diesel fuel needs. Even if you do have a reliable WVO source, if your commute is too short for the vehicle to warm up, the you won’t really benefit. If you don’t have space or time to devote to properly filtering your WVO, then it would be hard. But for those of us with significant commute distances, a WVO source and a desire to become less dependent on big oil, it certainly is an option.
