Transesterification of edible oils using Sr/Puralox SCFa-190 Zr20 doped alumina

Abstract This study evaluates the catalytic performance of strontium-based materials combined with Sasol Puralox SCFa-190 Zr20-doped alumina for the transesterification of soybean and canola oil to produce biodiesel. Catalysts were synthesized by impregnating the support with 30, 40, and 50 wt% Sr using Sr(NO 3 ) 2 , followed by calcination at 750 °C. XRD analysis revealed the formation of well-crystallized strontium aluminates, primarily Sr 3 Al 2 O 6 and SrAl 2 O 4 , with the structures observed by SEM. The catalyst surface exhibited progressive morphological changes, progressing from needle-like features to coral-like aggregates and finally to compact, cement-like structures. 40 % of Sr catalysts (40 SrPx) exhibited high catalytic performance due to the crystallinity of Sr 3 Al 2 O 6 , which provided abundant and strong basic sites. Under enhanced conditions (55 °C, methanol:oil 10:1, 4 % catalyst, and 2 h), a maximum biodiesel yield of 97 % was achieved with canola oil. The catalyst demonstrated reasonable stability, yielding 76.5 % after four cycles. The combination of Sr and Puralox SCFa-190 Zr20 is an effective and reusable catalyst for biodiesel production.