Mesoporous Silicas as Basic Heterogeneous Catalysts for the Formation of Biodiesel

Abstract

The principal aspects of the production of biodiesel using heterogeneous catalysis are presented, comparing this alternative process to conventional (homogeneous) processes and evaluating the main operational parameters. The most important techniques for the preparation and characterization of silicas with basic properties are mentioned, dividing these materials into two groups with distinct properties: as-synthesized silicas, especially the M41S family, with their pores occluded with organic cations, and functionalized silicas, with accessible pores. The catalytic properties of these silicas were evaluated in transesterifications using a model reaction and vegetable oil. Finally, a brief presentation is made of other solid catalysts with basic properties that can be used in the biodiesel production reaction.