The Crown biodiesel distillation process can be used as a method to clean up a methyl ester that does not meet the proper biodiesel specification. However, it is usually designed to make biodiesel into even better quality biodiesel by improving the cold flow characteristics. This is accomplished by distilling the biodiesel and leaving behind a lot of the monoglycerides and other low-volatile components.
Crown uses a high-vacuum, high-temperature distillation column to separate the desired biodiesel components from the undesired components. The high-quality biodiesel produced can far exceed the quality needed for use as a fuel. Therefore, it is sometimes used for only a portion of the produced biodiesel and then blended with normal biodiesel in order to achieve a nominal gain in quality or to offer a product to customers who desire a product that has a much stricter standard than the normal biodiesel.