High-quality biodiesel requires a precise high-tech process. Biodiesel starts off with feedstock biological material like soybean oil, inedible corn oil, waste animal fats, and used cooking oil. The first step to ensure high-quality biodiesel involves removing impurities from the feedstock through a refining process called pre-treatment. The refined feedstock is blended with alcohol in the presence of a catalyst chemical. This is called trans-esterification, which creates two products, methyl esters – the chemical name for biodiesel and glycerin, a valuable byproduct that’s used in soaps and other products. Once the glycerin is separated, the methyl esters are washed and the remaining methanol is removed with additional steps, which increases the quality of the finished product. One of the most critical steps in the production process is the purification phase.