Potassium hydroxide and calcium oxide activated carbon for transesterification reaction of biodiesel

Abstract

Biodiesel is an alternative renewable resource for the diesel fuel which is decreasing in resources and environmentally harmful. In this study, biodiesel was produced from transesterification process between rice bran oil and methanol with the presence of catalyst. The catalyst used was activated carbon prepared from palm kernel shell with potassium hydroxide and calcium oxide loading via one-step activation technique. The prepared catalyst was characterized using Fourier Transform Infrared - Attenuated Total Reflection (FTIR-ATR) and Field Emission Scanning Electron Microscope (FESEM) while Gas Chromatography - Flame Ionization Detector (GC-FID) was used to characterize the biodiesel produced from transesterification reaction. The main functional group of the prepared catalyst which is hydroxyl group, carbonyl group, C=C stretching and C-H bending for aromatic compound were observed using FTIR-ATR. The surface morphology of the modified carbon from FESEM shows the presence of pores with different sizes and shapes which leads to better transesterification process. The percentage of fatty acid methyl ester (FAME) yield of the biodiesel produced was 86%. Catalyst loading, methanol to oil ratio, reaction temperature, and reaction time was studied to obtain the best reaction condition to produce biodiesel. The optimum biodiesel production was at 0.8 g catalyst loading with 95% of FAME yield, 9:1 methanol to oil ratio producing 87% FAME yield, 65°C reaction temperature which produce 96% FAME yield and 91% FAME yield obtained from 6 hours reaction time. The biodiesel production at this optimum reaction condition shows 99% of FAME yield.