Fuel, Vol.203, 488-500, 2017
Efficient mesoporous SO42 /Zr-KIT-6 solid acid catalyst for green diesel production from esterification of oleic acid
Highly ordered mesoporous sulphated Zr-KIT-6(x)) [x = Si/Zr] solid acid catalysts were successfully synthesized by hydrothermal method. Different weight fractions of zirconium were loaded into fixed gel in the acidic medium and then sulphated to get sulphated Zr-KIT-6(x)) catalysts. X-ray diffraction (XRD), surface area analysis (Brunauer-Emmett-Teller equation) and microscopic techniques (SEM and TEM) results suggest the incorporation of Zr4+ into the silica KIT-6 framework by isomorphous substitution between Zr4+ and Si4+ ions. Diffuse reflection spectroscopy (DRS-UV) results reveal that Zr atoms are highly dispersed in +4 oxidation state. During the experiments it was observed that sulphated Zr-KIT-6 920) showed the highest catalytic conversion for esterification of oleic acid 996%) and transesterification of jatropha oil 985%) at an optimized reaction conditions of 120 degrees C, 20: 1 methanol to reactant molar ratio, 4 wt% catalyst loading and 6 h reaction time. The ester yields of 95% and 80% obtained from oleic acid and jatropha oil respectively. The used catalysts could be recycled up to three cycles with significant activity and stability. (C) 2017 Elsevier Ltd. All rights reserved.
Keywords:Mesoporous;Transesterification;Sulphation;Esterification;Biodiesel;KIT-6 (Korean Institute of Technology-6)