Esterification of Acidic Oils over a Versatile Amorphous Solid Catalyst

An amorphous SiO2-ZrO2 catalyst shows high activity in the esterification of free fatty acids contained in vegetable oils while at the same time promoting the transesterification of triglycerides. The catalyst is a good candidate for low-waste deacidification pretreatment or for one-pot biodiesel prodn. process starting from oils with high acid content.