Which catalysts or processes are most effective when converting beef fat with potentially high free fatty acid content into biodiesel?

If the FFA content exceeds 2–3%, a two-step process is preferred: 1) Acid-catalyzed esterification using sulfuric acid to lower FFAs, followed by 2) Base-catalyzed transesterification using NaOH or KOH. This prevents soap formation and ensures high biodiesel yield. The GlobeCore USB biodiesel plant supports both stages with automated dosing and reaction control, allowing reliable conversion even with raw or low-grade tallow. For low-FFA tallow, base-catalyzed transesterification alone is sufficient.