Palm Acid Oil (PAO) is a biofuel feedstock derived from Palm Oil Mill Effluent (POME). PAO is a by-product of the chemical refining of palm oil and consists of FFA (over 50%) and neutral oil, with 2-3% moisture and other impurities. It is very similar to palm fatty acid distillate (PFAD), but its FFA is generally lower. PAO is increasingly used for mixing in biofuel transportation fuel.