Patent ID: 7695533

Claim:
A biodiesel production method, comprising: (a) providing a homogeneous reaction mixture in a first apolar phase, the reaction mixture comprising: a refined vegetable oil; a C1-C4 alcohol; a catalyst, and an aliphatic hydrocarbon solvent with a boiling point of 40-200° C.; (b) allowing the refined vegetable oil to undergo transesterification whilst maintaining a homogeneous mixture comprising transesterified fuel, non-transesterified vegetable oil and aliphatic hydrocarbon solvent in said first apolar phase; and forming a first polar phase comprising glycerol by-product; (c) separating the first apolar phase and the first polar phase; and (d) refining the transesterified fuel from the first apolar phase, wherein the C1-C4 alcohol is used in an amount selected from the group consisting of: a stoichiometric amount; and an excess not exceeding 30% of a stoichiometric amount, and the aliphatic hydrocarbon solvent is used in an amount of at least 0.2 parts by volume relative to the unit volume of the refined vegetable oil.