A small-scale demonstration plant was designed, set up, and operated for the heterogeneously catalyzed synthesis of biodiesel under supercritical conditions. An Aspen Plus (R) model was applied to minimize the energy demand for the product purification stages. Vacuum distillation followed by a small rectification column was identified as the optimum solution. The determination of the energy demand of the plant revealed the economic viability of the process as far as the energy consumption is concerned. The catalyst incorporated into the plant was selected through a screening procedure applying tricaprin as model substance. g-Al2O3 modified by acid treatment and La2O3 supported by g-Al2O3 proved to be the most promising candidates. The stability of these formulations was proven by long-term stability tests.