WHAT IS THE CHEMICAL DIFFERENCE IN THE ULSD FUEL?
There is no major chemical difference between current diesel fuels and ULSD. ULSD is just further processed to remove more sulfur. There are, however, certain fuel characteristics that may be affected: • LUBRICITY – Diesel fuel must adequately lubricate the fuel injection system components. The processing required to reduce sulfur to 15 ppm also removes naturally occurring lubricity agents in diesel fuel. All ULSD fuel will meet the required lubricity specification. Lubricity additives will be used if needed. • FUEL DENSITY – The processing required to reduce sulfur to 15 ppm can reduce density of the diesel fuel, resulting in a slight reduction in energy content (BTU/gal). • CETANE – The processing required to reduce sulfur to 15 ppm reduces the aromatics content resulting in an increase to the cetane number. Any improvement in cetane will vary with refinery source. • COLD FLOW – The processing required to reduce sulfur to 15 ppm may affect cold flow response. Cold flow requirements c
