Hydrocarbon Renewable and Synthetic Diesel Fuel Blendstocks: Composition and Properties

The properties of synthetic paraffinic and hydrotreated renewable diesel fuels follow logically from their composition. Comprehensive two-dimensional gas chromatographic analysis with nonpolar and polar columns and ¹³C NMR are powerful techniques for determining the bulk composition of these fuels. These techniques were used to determine the carbon number distributions of total, normal, and isomerized paraffins in a variet y o f samples, including a Fischer-Tropsch diesel from coal and hydrotreated renewable diesel fuels from vegetable oils, animal fats, and algal oils. The detailed compositions were crucial to providing deeper insight into t h e chemic al and physical property trends. In particular, the compositions were able to elucidate the general differences in properties, such as low temperature operability, ignition delay, distillation profile, density, kinematic viscosity, and net heat of combustion. These properties in particular are crucial to predicting the successful performance of the fuels for use in compression-ignition engines. In each of the fuels, the fraction of normal to isomerized paraffins and the shape of the carbon number distributions had the largest influence on these properties.