Biodiesel winter use considerations help ensure smooth operations
Chris Case is the facility manager at Pictured Rocks National Lakeshore, a national park on the shores of Lake Superior, the largest, deepest and coldest of all the Great Lakes. He has run biodiesel-blended fuel in his park vehicles since 1999, and he knows a thing or two about running biodiesel in cold weather. Biodiesel Magazine spoke with Case about some of the best practices he has used to avoid temperature-related issues when running biodiesel blends in the cold winter months.
“When splash blending into an above ground storage tank, make sure that the time between transferring the warmed up B100 to the tank and adding the petroleum diesel is not delayed,” he said. “They need to be mixed almost simultaneously.”
Case said other than paying attention to temperature when transferring and mixing B100, a user simply needs to treat the vehicle as if petroleum was the only fuel used. “If you need to plug in heaters for your petroleum diesels do the same for biodiesels,” he said. “If operators are not comfortable with B20 in cold temperatures, drop the blend to B15 or B10.”
According to the National Renewable Energy Lab's Biodiesel Use and Handling Guide (Fourth Edition), guidelines to follow for storing B100 in winter months include:
- Storing the fuel at temperatures that are 5 to 10 degrees above the cloud point of the B100.
- B100 can be stored underground in most cold climates without needing to do anything else because most underground storage temperatures are typically above 45 degrees F. Above-ground storage and handling systems should be protected with insulation, agitation, heating systems, or other measures if temperatures regularly fall below the cloud point. This includes piping, tanks, and pumping equipment.
Of importance, the Guide also notes, “B100 in the United States cannot be effectively managed with current cold flow additives, as can some petroleum diesel or European rapeseed-oil-based biodiesel. The level of saturated compounds in U.S. oils and fats is too high for most additives to be effective. Cold flow additives’ effectiveness can also change dramatically, depending on the exact type of biodiesel and the processing it has undergone; this is much like the situation with diesel fuel. Cold flow additives have been used much more successfully with biodiesel blends. You should work directly with the additive manufacturers on this issue.”
Regarding biodiesel blends, the Guide states, “When biodiesel is blended with diesel fuel, the key variables are the properties of the diesel fuel, the properties of the biodiesel, the blend level, and the effectiveness of cold flow additives.”
For more information from the Biodiesel Use and Handling Guide (Fourth Edition) and low-temperature recommendations for for B100 and biodiesel blends, click here.