Abstract: Glyceride-containing feed for a base catalyzed transesterification with lower alkanol to make biodiesel is pretreated with glycerin separated during the transesterification to partially convert glycerides with lower alkanol contained in the separated glycerin using base catalyst in the separated glycerin while reducing the free fatty acid and phosphorus compound concentrations in the glyceride-containing feed. Unique producer compositions are provided by the pretreatment processes.

Abstract: The effluent from an acid esterification of free fatty acid with alkanol to produce alkyl ester of fatty acid is contacted with glycerin to remove water and alkanol. The alkanol separated with the glycerin can be recycled to the acid esterification by contacting the glycerin with fatty acid-containing feed being passed to the acid esterification.

Abstract: Waste water emissions from a biodiesel production facility are substantially reduced by recovering water from a spent water stream used in a water washing step in the refining of crude biodiesel which water washing removes glycerin. The water is recovered from the spent water stream is concentrated to provide an aqueous fraction which can be recycled for the water washing. The concentration also provides a glycerin-containing fraction containing that can be blended with crude glycerin by-product generated by transesterification of glycerides to make the biodiesel.

Abstract: Glyceride-containing feed for a base catalyzed transesterification with lower alkanol to make biodiesel is pretreated with glycerin separated during the transesterification to partially convert glycerides with lower alkanol contained in the separated glycerin using base catalyst in the separated glycerin while reducing the free fatty acid and phosphorus compound concentrations in the glyceride-containing feed. Unique producer compositions are provided by the pretreatment processes.

Abstract: Basic metal salt of glycerin is used as transesterification catalyst or an intermediate to an anhydrous transesterification catalyst for the base catalyzed process for making biodiesel from fats and oils.