Conversion of fatty acid into biodiesel using solid catalysts of Ti-Zr and Ti-Cr pillared bentonite

Biodiesel can be obtained as an alternative fuel from the catalytic esterification reaction of fatty acids using a solid catalyst. Bentonite can be modified through the pillarization technique to improve its physicochemical properties to meet conditions as a solid catalyst. This study prepared the solid catalysts by the pillarization of bentonite (PILC) using the single metal of Ti, Zr, and Cr as the pillars. The pillars with double metals of Ti-Zr and Ti-Cr were also prepared with the mole ratios of Ti/Zr or Ti/Cr around 1:9, 1:1, and 9:1 sequentially. The prepared solid catalysts were characterized using XRD, XRF, BET surface area, and NH3−TPD. The fatty acid esterification was conducted at a temperature of 150 oC for 3 hours and a pressure of 20 bar using the oleic acid as a model compound of fatty acid. Based on the several characterization results, it is concluded that the pillarization process of bentonite was successfully obtained even using single metal and double metals of Ti-Zr and Ti-Cr as the pillars. Moreover, Ti-Zr/PILC (1:9) catalyst showed a higher activity result on the esterification reaction of fatty acids into biodiesel with a conversion of 74.83% due to the surface area and acidity of Ti-Zr/PILC (1:9) catalyst is superior to the other prepared catalysts.