Sulfur Removal Strategies for Biodiesel Production

High FFA fats, oils and grease are feedstock for ASTM 6751 biodiesel.  These feedstocks contain higher levels of sulfur than traditional feedstocks.  Common oil crops contain sulfur species that are water soluble and remain with the meal during oil processing.   High FFA feedstocks from cooking and rendering operations contain oil soluble sulfur species that require additional processing steps to produce ASTM 6751 biodiesel that meets the 15 ppm sulfur specification.  It all begins with good feedstock characterization.