The main method is base-catalyzed transesterification, using methanol and NaOH or KOH. Acid esterification may be used first if the palm oil has high free fatty acid content. The GlobeCore USB plant supports both processes, with flexible settings for different oil qualities. It includes stages for refining, reacting, separating, and drying, making it suitable for processing both crude and refined palm oils into high-grade biodiesel.