Using biodiesel in cold weather can require special care
With an increase in the use of biodiesel fuels, operators should be aware of tips for engine performance and storage safety, particularly in winter, says a University of Missouri agricultural systems management professor, according to a University of Missouri release.
"Commercially produced biodiesel is a safe and reliable alternative fuel that can be used in diesel engines with little or no need for modifying engines or fuel systems," says Leon Schumacher.
Petroleum-based diesel and biodiesel both can thicken or gel as the temperature drops. Gelled fuel can clog fuel filters or become too thick to be pumped from the fuel tank to the engine.
Generally speaking, biodiesel gels faster than its petroleum-based counterpart.
The appropriate blend, with a smaller biodiesel proportion, should be used in colder weather to avoid flow problems, Schumacher says. Most biodiesel fuels are blends of bio and petroleum fuels referenced with the letter "B" followed by a one- or two-digit number. That number represents the percentage of biodiesel used in the blend. The most common biodiesel blends are B-2, B-5, B-10, B-20 and B-50. Pure biodiesel, sometimes called "neat" biodiesel, is designated B-100.
Use care when pumping biodiesel blends into older vehicles the first time. Biodiesel is an excellent solvent and can dissolve varnishes and other deposits that have collected in the vehicle's tank or fuel lines over time. That may lead to premature filter plugging for the first few tanks of fuel.
Fuel lines of some older model vehicles (pre-1993) may need to be replaced since biodiesel reacts with natural rubber which was commonly used in those fuel systems, Schumacher said.
Biodiesel blends, like petroleum diesel blends, should be stored in a clean, dry, dark environment. As with storing any fuel, take steps to prevent water from entering the tank. Algae can grow in biodiesel fuels just as in pure petroleum diesel fuels, he said.
Existing storage tanks should be cleaned, inspected and repaired before converting to biodiesel storage. Older tanks should be professionally cleaned to remove particles and deposits that might contaminate the fuel supply.
Tanks should be clearly labeled to indicate the type of fuel to be stored in the tank. Storage tanks for biodiesel can be constructed from mild steel, stainless steel, fluorinated polyproethylene, fluorinated polypropylene and Teflon. Those same materials are suitable for plumbing in the storage system. Pure biodiesel, however, will readily dissolve rubber components.
Tanks or containers constructed of polyethylene or polypropylene always should be protected from the sun, Schumacher says.
Biodiesel reacts unfavorably with material such as aluminum, nonferrous metal, tin and zinc, which reduces the fuel's shelf life. Biodiesel also will break down concrete, varnish and PVC tank linings.
Neat biodiesel is non-toxic, biodegradable and less irritating to the skin than is petrodiesel.