Trucking study examines biodiesel efficiency
A new study underway examines the benefits of a 20% biodiesel blend (B20) in an over-the-road trucking company. First-year results of the study have shown that biodiesel performs similarly to diesel fuel in trucks.
"The trucking industry is by far the single largest consumer of diesel fuel, using 38 billion gallons annually. This study demonstrates in a real-world environment that biodiesel can be used successfully year-round," says Grant Kimberley, director of market development for the Iowa Soybean Association, a partner in the study.
The two-year study, called the "2 Million Mile Haul," is believed to be the first comprehensive, publicly documented demonstration of B20 in over-the-road trucks.
"Although we have data from only the first year of the study, we are pleased with the results to date," says Don Heck, coordinator of biotechnology and biofuels programs at Iowa Central Community College in Fort Dodge, Iowa. "Preliminary results are that B20 biodiesel performs similarly to 100 percent diesel. We found a slight decrease in overall fuel efficiency for the B20 group of trucks, but it was not statistically significant. In fact, the difference was several times smaller than the driver-to-driver variability in fuel efficiency within each group."
The study also examines the effects of various fuel additives on the cold-flow properties of biodiesel blended with the new 2007 Ultra-Low Sulfur Diesel (ULSD), focusing primarily on the cloud, plug and pour points.
The study consists of two groups of 10 Decker Truck Line Inc. semi tractors running with flatbed trailers on matched routes to either Minneapolis or Chicago. The control group uses 100% No. 2 petroleum diesel. The B20 test group uses a blend of 20% biodiesel from Renewable Energy Group, Inc. and 80% No. 2 petroleum diesel. Data is routinely analyzed for fuel efficiency, maintenance records and fuel quality.
More than 1.5 million miles had been logged by the end of the first year leading up to October 1, 2007. Overall fuel efficiency, including idle time, was slightly reduced in the B20 group. Average fuel consumption for the control group was 6.29 miles per gallon (mpg) and for the B20 group it was 6.15 mpg. The fuel efficiency difference of 2.2% between groups is not considered significant, especially when compared to driver variability.
Driver fuel efficiency ranged from 5.72 mpg to 7.40 mpg for the control group, a 23% spread. For the B20 group, fuel efficiency ranged from 5.76 mpg to 7.00 mpg, an 18% spread among drivers.
Winter driving resulted in relatively few problems regarding cold-flow issues. Fuel for both groups was treated with a commercial fuel additive, and No. 1 diesel, a 40% blend, was used for a brief time during a severe cold snap in February 2007. No drivers experienced fuel gelling problems.
Early in the study, a few filter plugging problems occurred in trucks using the B20 blend. After changes were made in blending of the biodiesel fuel in early February 2007, the rate of filter plugging for the B20 group dropped significantly.