Effective biodiesel synthesis from palm fatty acid distillate (PFAD) using carbon-based solid acid catalyst derived glycerol

Abstract

Cost efficient and environmental friendly carbon derived glycerol (CG) was prepared by insitu carbonication and sulfonation process. The synthesized CG was sulfonated with H2SO4 for 10 h denoted as SCG-(10) catalyst. The physico-chemical properties of the prepared catalyst were characterized by using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), temperature programmed desorption-ammonia (TPD-NH3), Brunauer–Emmett–Teller (BET) surface area, variable pressure scanning electron microscope (VPSEM), high resolution transmission electron microscopy (HR-TEM) and CHNSO elemental analysis. The specific surface area and total acidity were increased significantly after being sulfonated at different time of reflux; whereas, the SCG-(10) catalyst showed the highest total amount of acidity (35117.14 μmol/g). Esterification of palm fatty acid distillate (PFAD) was successfully obtained high fatty acid methyl esters (FAME) with yield 97.8% at optimum parameter of 18:1 methanol to PFAD molar ratio, 5 wt% catalyst loading and 90 °C reaction temperature within 1 h. The catalyst was successfully reused for 7 cycles and it was found that the catalytic activity maintained with >96% of FAME yield for the first three run. The regenerated SCG-(10) catalyst has been used for another four consecutive of reusability run indicates the viability of utilizing carbon catalyst derived glycerol for biodiesel production.