TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Composition: The reaction mixture is provided by mixing oil with a solution comprising methanol and alkaline catalyst comprising sodium methylate at 150% stoichiometric methanol. The reaction mixture includes alkaline catalyst in an amount of 1-1.5 wt.% of the oil. Preferred Process: Transesterification is accelerated through high-intensity mixing of the reaction mixture and subjecting the reaction mixture to 65-250 degrees C. A glycerin phase of the resulting reaction product stream is separated from a biodiesel phase of the reaction product stream by passing the reaction mixture through a centrifugal separator (48) comprising a series of perforated concentric panels separating an axial region from a rim region of the separator, such that the glycerin and biodiesel phases pass through arrays of perforations in the panels of the series of concentric panels as the glycerin passes to the rim region and the biodiesel phase passes to the axial region of the separator. Stage (II) reaction mixture is provided by mixing the biodiesel phase of the reaction product stream with additional methanol and alkaline catalyst. Transesterification reaction of stage (II) reaction mixture is accelerated by subjecting the mixture to 65-250 degrees C, and the mixture is pressurized sufficiently to prevent boil-off. Stage (II) reaction mixture is provided by mixing the biodiesel phase with a solution comprising methanol and an alkaline catalyst comprising sodium methylate at 25% stoichiometric methanol. Alkaline catalyst is provided in stage (II) mixture to comprise 0.15 wt.% of incoming flow of the biodiesel phase. Surplus unreacted methanol is stripped from the biodiesel phase by passing the biodiesel phase through a vacuum distillation tower (42). The stripped unreacted methanol is passed into a condensation system to be condensed, and the condensed methanol is passed from the condensation system back to be recycled for use in the step of providing a reaction mixture. Any remaining catalyst is neutralized by passing the biodiesel product through an inline static mixer (46) and mixing the biodiesel product with an acid. After separation of glycerin phase, the resulting biodiesel product is washed using counter-current extraction. The washing process involves continuously passing the biodiesel product into a radially outer rim region of a counter-current centrifugal separator and continuously passing water in counter-flow fashion into a central axial region of the centrifugal separator such that the water is forced radially outward through the biodiesel product as the biodiesel product passes radially inward toward the central axial region. The counter-current centrifugal separator includes a series of perforated concentric cylindrical panels separating an axial region from a rim region of the separator, such that the water and the biodiesel product are passed in counter-flow fashion through arrays of perforations in the panels of the series of concentric panels as the water passes to the rim region and the biodiesel product passes to the axial region of the separator. The biodiesel phase is washed in a single-step water-wash process at 1-10%, preferably 2-5%, ratio of water to unwashed biodiesel phase.