Application of sulfated tin oxide in Transesterification of Waste Cooking Oil: An Optimization Study

摘要

Biodiesel is a biodegradable and non-toxic fuel which can be produced through transesterification reaction. However, it is impractical to use the refined vegetable oils as the feedstock for biodiesel production due to its high production cost and priority for food products. Thus, low-grade oil with high free fatty acids (FFA) content, typically waste cooking oil has been a promising choice to improve the economical feasibility of biodiesel. In the present study, superacid sulfated tin oxide catalyst, SO_4~(2-)/SnO_2 has been successfully prepared through impregnation method. Bimetallic effect was also studied at which SnO_2 mixed with SiO_2 and Al_2O_3, respectively at different weight ratio in order to enhance the catalytic activity of SnO_2. The effect of different reaction parameters such as calcinations temperature and period, reaction temperature, catalyst loading, methanol to oil ratio and reaction time were studied to optimize the reaction conditions. It was found that SO_4~(2-)/SnO_2-SiO_2 with weight ratio 3 exhibited an exceptional high activity with optimum yield 92.3% at reaction temperature 150oC, catalyst loading 3 wt%, methanol to oil ratio 15 and reaction time 3 hours.