Heterogeneous Catalysis in Biodiesel Production: The Influence of Leaching

The catalytic performances of several solid catalysts in the transesterification of vegetable oils with methanol were studied in small steel vials. The eventual presence of an homogeneous contribution to the catalysis—due to the leaching of the active phase—was also investigated. The behaviour of one of the more promising catalyst (TiO₂ supported on SiO₂) was further deepened in batch and continuous reactors by using the catalysts in pellets, to evaluate the possibility of developing an industrial process based on this catalyst. The catalyst life-time run, in a continuous tubular reactor, was determinant for this evaluation.