Avoid Problems When Using Biodiesel

Fuel quality is extremely important. Buy only biodiesel blends that use B100 meeting ASTM specification D-6751. Purchase from a producer, marketer, or distributor that has received BQ9000 accreditation as an extra level of assurance.

Use B1 or B2 with ultra-low sulfur diesel (ULSD) fuel. They provide the lubricity lacking with ULSD. B2 is sold throughout the Midwest, and several states are considering legislation requiring low-level biodiesel blends, ranging from B2 to B5. While neat biodiesel provides about 8 percent less energy compared to standard No. 2 diesel fuel, you really won’t see any difference in performance from B1 to B5.

Blends up to B20 can be used in existing equipment without modification. You might note a slight difference in torque, horsepower and fuel consumption, but only about a 1 to 2 percent loss.

Biodiesel blends should be stored at least 10 degrees F above the cloud point of the blended fuel. B20 should be stored for no longer than 6 months. It should be stored only for 4 months in hot and humid climates. Keep storage tanks protected from direct sunlight or frost. For engines used infrequently, run the engine on pure diesel fuel for 20 to 30 minutes to flush out all the biodiesel before storage.

Clean tanks before storing biodiesel. Even lower biodiesel blends like B5 can loosen accumulated sediment in tanks, especially if they’re old or have not been properly maintained.

Use a moisture dispersant and biocide. Biodiesel is a rich food source for microbes that produce filter clogging sludge. Keep tanks topped off to prevent condensation and make sure filler caps are tightly attached.

Do not use "homemade" biodiesel. Raw or refined vegetable oil or recycled greases that have not been processed into biodiesel are not biodiesel and do not meet ASTM D-675. They can result in engine deposits, ring sticking, lube oil gelling, and other problems due to their greater viscosity. Using homemade fuels could void warrantees. Federal law requires manufacturers to honor warranties unless it can be shown that the use of biodiesel caused the failure.

Pure B100 or blends like B30 or B50 require special handling and may require modifications to equipment. Besides dissolving sediments in tanks and fuel systems, they can ruin fuel pumps, clog filters or soften and degrade rubber hoses and gaskets. Extensive contact with copper, brass, bronze, lead, tin or galvanized surfaces may accelerate fuel oxidation.