Biodiesel and biodiesel blends are known to cause fuel filter clogging in vehicles at low temperatures. This is often due to waxy fatty acids crystallizing in the fuel at low winter temperatures. The objective of this work is to determine the feasibility of separating a fatty acid from a given stream using low temperature crystallization. Separation by crystallization can reduce the amount of chemicals added to biodiesel that can cause the alternative fuel to lose its environmentally friendly status. Removing the unwanted fatty acids can also lower the fuel viscosity and enhance the cold flow operability of biodiesel.

Crystallization experiments are performed with oleic acid and linoleic acid in acetonitrile. A range of various operating conditions is used to determine the percentages of waxy crystals that can be removed. Since these materials can also be sold as byproducts, the purities of the crystals are also determined. Results from this investigation are presented.