NOVELTY - Producing biodiesel comprises agitating a natural oil containing triglycerides with a neutral buffer solution in a reactor (123) in a presence of a biocatalyst to form free fatty acids and glycerol; removing the glycerol form the reactor; transesterifying the free fatty acids with methyl acetate at a predetermined temperature to obtain biodiesel and unreacted free fatty acids; removing the buffer solution and biocatalyst from the reactor; and completing the transesterification by reacting the unreacted free fatty acids with methanol to produce biodiesel.    USE - The process is useful for producing biodiesel (claimed) which is used as cooking fuel, and automotive fuel without the need to mix with different petroleum-derived diesel.    ADVANTAGE - The process: requires less energy, lowers the production cost and produces higher yield of biodiesel; reduces saponification due to the neutral buffer solution; provides 98% conversion rate within 1-3 hours; recycles palm oil mill effluent; produces biodiesel that has low flash point (which enable it to be stored throughout the year without any change of its properties), a smoke-free flame and no smell when burned; and is environmental friendly.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a system for producing biodiesel comprising: a buffer tank (105) containing a neutral buffer solution; an oil tank (101) containing a natural oil; an enzyme storage tank (117) containing a biocatalyst; a reactor for mixing the buffer solution from the buffer tank, the natural oil from the oil tank and the biocatalyst from the enzyme storage tank and agitating the mixture to produce free fatty acids and glycerol; a methyl acetate feedstock (119) for providing methyl acetate to transesterify the free fatty acids in the reactor to form biodiesel and unreacted free fatty acids; and a methanol feedstock for providing methanol to complete the transesterification between the unreacted free fatty acids in the reactor to produce biodiesel.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the process for producing biodiesel and system of biodiesel production from natural oil.    Oil tank (101)    Buffer tank (105)    Enzyme storage tank (117)    Methyl acetate feedstock (119)    Reactor (123)