Lubricity Effects of Biodiesel when Used with Ultra Low Sulfur Diesel Fuel

Diesel fuel was sold in the United States with a sulfur level of 5000 ppm until October 1993. At that time, the EPA mandated that all diesel fuel sold in the United States contain 500 ppm or less sulfur. The EPA reduced the sulfur standard to 15 ppm for diesel fuel again on 1 June 2006. Each time the level of sulfur has been lowered, the lubricity of the diesel fuel has dropped. Fifty-five gallons of No. 2, 15-ppm sulfur diesel fuel were obtained and blended with biodiesel on a volume basis at the 0.5%, 1%, and 2% levels of biodiesel. Similarly, No. 1 diesel fuel (15 ppm or lower) was blended with biodiesel on a volume basis at the 1% and 2% levels. An independent laboratory conducted SLBOCLE tests to determine the lubricity of each blend. The number two fuel, when blended at the rate of 1% and 2% exceeded lubricity standards currently proposed for diesel fuel used in Europe. The number one fuel blended at the rate of 1% and 2% biodiesel failed to meet lubricity standards currently proposed for diesel fuel used in Europe.