There have been a lot of inquiries lately about biodiesel conversion kits. The page you’re looking for, with information originally published in the New York Times, is here, but hold on a second -- we need to clarify something.
If you’re already running a diesel vehicle and have access to biodiesel that has already been processed (transesterified) to ASTM D-6751 standards, you don’t need a conversion kit. You can put that biodiesel straight into your tank and run your vehicle on it at any concentration up to 100 percent (B100). Generally, this is commercially processed soy biodiesel, but it can come from other sources as well. See more on this here.
The photo above shows a 55-gallon drum, an 11-gallon portable tank, and a 5-gallon jerry jug filled with commercial soy B100. We mix this with petrodiesel at different percentages, depending on the weather.
The biodiesel conversion kits you hear about are for use with straight vegetable oil (SVO) or waste vegetable oil (WVO) fuels. These do require some different equipment and modifications to your vehicle. There’s plenty of good information on SVO and WVO systems on the Internet, and not much of it is in conflict. For more on this, read the information published online by the conversion kit makers. Also look at journeytoforever.org, and the U.S. Department of Energy’s biodiesel page.
So, if it turns out you’re interested in running commercial-grade “out of the box” biodiesel, all you have to do is find it and buy it. Here’s a link to local sellers.
A few cautionary notes:
- If you want to use biodiesel in an older, carbonized engine, be aware that it acts as a solvent, and might clean your fuel system a little more quickly than you’d want. Change your fuel filters soon after starting on the biodiesel, and be ready to change them again before you normally would, to avoid fouled injectors. Soon, however, you should notice a smoother-running engine, with lower fumes and emissions.
- In high concentrations, biodiesel will eventually soften and destroy natural-rubber hoses. This isn’t a problem in most newer diesels, but if you want to run it in an old farm tractor or an engine that’s been around for more than about a decade, change the hoses first.
- There are conflicting reports about minor horsepower losses (around 8 percent) in engines running B100. Some people say they have experienced a loss, some say they haven’t. Those who think there’s a loss also say that cutting the biodiesel with almost any amount of petrodiesel will bring back any lost power.
- Biodiesel does gel sooner than petrodiesel in cold weather. Again, mixing some petro with the bio will reduce gelling problems, although in really frigid temperatures the mix should be heavily weighted towards the petro.
We run a VW Beetle TDI and an Isuzu-diesel powerboat on a B80 mixture in warm weather, and a B20 mixture in cold weather, mixing everything by hand and filling all tanks from five-gallon jerry jugs. When the weather gets under about 40 degrees F. we keep the on-deck jerry jug inside.
We use diesel fuel additives year-round. There’s some doubt whether the anti-gelling additive that works for petro-diesel in winter has any effect on the biodiesel in the mix, but it doesn’t seem to hurt.
AUGUST 2008 UPDATE: We're now using B100 derived from rendered animal fat, not soy. Fat-based B100 has a slightly higher viscosity rating and different gelling characteristics than soy-based fuel. So far, we have noticed no difference in power output. We buy our fuel from Guilford, Connecticut-based Greenleaf Biofuels.
~ Doug Logan, New Energy Watch
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