NOVELTY - Processing a glycerol-containing feed (101), comprises separating a mixture comprising glycerol and fatty acids into a glycerol-rich portion (109) and a fatty acids-rich portion, where the glycerol-rich portion comprises glycerol, methanol and water, and reacting the glycerol-rich portion with an acid comprising phosphorus to produce a reacted product comprising glycerophosphoric acid, any unreacted glycerol, and any unreacted acid.    USE - The method is useful for processing a glycerol-containing feed into one or more products.    ADVANTAGE - The method allows economical processing of a glycerol-containing feed with less consumption of byproducts.    DETAILED DESCRIPTION - Processing a glycerol-containing feed (101), comprises either separating a mixture comprising glycerol and fatty acids into a glycerol-rich portion (109) and a fatty acids-rich portion, where the glycerol-rich portion comprises glycerol, methanol, and water, and reacting the glycerol-rich portion with an acid comprising phosphorus to produce a reacted product comprising glycerophosphoric acid, any unreacted glycerol, and any unreacted acid; or decreasing a pH of a biodiesel by product comprising fatty acids, glycerol, water, methanol, inorganic salts and organic salts to produce a mixture comprising a glycerol-rich portion and a fatty acids-rich portion, where the glycerol-rich portion comprises glycerol, methanol, water, organic salts, and inorganic salts, removing a portion of the methanol contained in the glycerol-rich portion to produce a methanol-lean glycerol-rich portion comprising the glycerol, water, and a remaining portion of the methanol, and reacting at least a portion of the methanol-lean glycerol-rich portion with a first acid to produce a reacted product comprising glycerophosphoric acid, any unreacted glycerol, and any unreacted first acid; or mixing a biodiesel by product having a pH of 6-13 with a first acid comprising phosphorus to produce a mixture having a pH of 2-5, where the biodiesel by product comprises fatty acids, glycerol, methanol and water, separating the mixture into a glycerol-rich portion and a fatty acids-rich portion, where the glycerol-rich portion comprises 30-85 wt.% of glycerol, 5-35 wt.% of methanol, and 5-40 wt.% of water, and reacting at least a portion of the glycerol-rich portion comprising 30-85 wt.% of glycerol, 5-35 wt.% of methanol, and 5-40 wt.% of water with a second acid comprising phosphorus at conditions sufficient to produce a reacted product comprising glycerophosphoric acid, water, any unreacted glycerol, any unreacted first acid, and any unreacted second acid.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a method for processing a glycerol-containing feed.    Glycerol-containing feed via line (101)    Acid via line (103)    Glycerol-lean portion (107)    Glycerol-rich portion (109)    Neutralized product via line. (133)