Patent ID: 7637969
Filing Date: 2009-12-29
Classification: C10G,C10L,C11C,Y02E,Y02P

Abstract:
1. In a process to produce a biodiesel fuel comprising the step of transesterifying a triglyceride comprising a vegetable oil or animal fat with methanol or ethanol in the presence of an acid or base catalyst to produce a mixture of methyl or ethyl esters of fatty acids and crude glycerine; the improvement wherein the transesterifying is carried out in the presence of methyl or ethyl acetate, wherein the transesterifying step is a first step (a), and the process further comprises the steps of (b) isolating the crude glycerine from the mixture; (c) reacting some or all of the crude glycerine isolated in step (b) with an aldehyde, ketone, acetic acid, methyl acetate or ethyl acetate to obtain an acetal, ketal, glycerine acetate or a mixture thereof as reaction product; and (d) mixing the reaction product of step (c) with the methyl or ethyl esters of fatty acids obtained in step (a) to produce the biodiesel fuel, wherein in step (d) the mixture formed by mixing the reaction product of step (c) with the methyl or ethyl esters of fatty acids contains between about 0.1 and 20% by weight of the acetal, ketal, glycerine acetate or mixture thereof.