NOVELTY - Grease with high acid value, methanol and acid catalyst are added to an esterification mixing tank continuously, and pumped into esterification fiber-film reactor. The mixture is reacted, and methanol is removed. The material free of methanol is pumped to fiber film water knockout drum to separate acid-containing wastewater, and conveyed to a secondary reaction system. The processed material is supplied to ester exchange system. The esterified material, methanol and alkali catalyst are added and reacted. Methanol is removed, and biodiesel is manufactured.    USE - Continuous esterification and ester exchange process for manufacture of biodiesel.    ADVANTAGE - The biodiesel is efficiently manufactured by continuous esterification and ester exchange process.    DETAILED DESCRIPTION - Grease with high acid value, methanol and acid catalyst are mixed and added to an esterification mixing tank continuously, and pumped into an esterification fiber-film reactor by a pump. The mixture is discharged from the bottom of reactor, and a portion is returned to the esterification mixing tank. Methanol of remainder portion is removed in a methanol removing tower by distillation, and methanol is discharged from the top of tower. Methanol is conveyed to a recycling system, and material free of methanol is supplied to fiber film water knockout drum by a pump. The acid-containing wastewater is separated, and conveyed to a secondary reaction system. The wastewater is conveyed to a wastewater treatment system, and water is treated. The processes are repeated to complete esterification reaction. The acid-containing wastewater discharged from the secondary reaction system is returned to the esterification mixing tank of the primary reaction system. The material from the esterification system, methanol and alkali catalyst are added to esterification mixing tank continuously, and pumped into an ester exchange fiber-film reactor. The reaction product is discharged from the bottom of reactor, and a portion of product is returned to esterification mixing tank. Methanol is removed in a methanol removing tower, and supplied to methanol recycling system. The material free of methanol is pumped into sedimentation tank, after settling and separating glycerin. Glycerin is separated from the bottom of sedimentation tank, and conveyed to a sedimentation tank refined system. Thus, biodiesel is manufactured by continuous esterification and ester exchange process.