Biodiesel production from jatropha seeds with bead-type heterogeneous catalyst

This study adapted two types of heterogeneous catalysts to the process of manufacturing biodiesel through a two-stage process using Jatropha oil as a raw material. The acid value of Jatropha oil prepared in this study was 11.3 mgKOH/g, and it could be reduced to less than 0.4 mgKOH/g via 2 h of esterification using the Amberlyst-15 catalyst. The pretreated oil was used as a raw material for transesterification in a Carberry spinning catalyst basket reactor equipped with a bead-type dolomite catalyst, as the bead-type dolomite catalyst prepared with 20 wt% pseudoboehmite sol as an inorganic binder was found to be the optimal catalyst for the transesterification reaction. The spent dolomite bead catalyst could be regenerated and reused twice without a loss of activity during transesterification. However, the catalyst when repeatedly regenerated three times nearly lost its active sites, which is attributed to the conversion of CaO to CaCO₃ during the regeneration and reuse procedure.