Synthesis and evaluation of catalytic activity of calcined sodium silicate for transesterification of waste cooking oil to biodiesel
International Journal of Renewable Energy Research
School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Wits, Johannesburg, South Africa
Biodiesel production from waste cooking oil (WCO) using heterogeneous sodium silicate catalyst is presented in this article. The conversion of WCO to biodiesel exploited the potential of the catalyst to convert high free fatty acid (FFA) content feedstock to biodiesel directly, thereby by-passing the esterification stage whereby FFA content of the feedstock is reduced prior to transesterification reaction. In the study, effect of reaction temperature and reaction time on the activity of the catalyst during transesterification of WCO to biodiesel was investigated. The transesterification reaction was conducted in a batch reactor with 2.51 g of the catalysts and at WCO to methanol ratio of 1:6. In addition, the reaction temperature was varied between 25°C to 63°C, and the reaction time was varied from 0 to 180 minutes at a 30 minute step increase. The fatty acid methyl ester (FAME) yield increased with reaction time and reaction temperature and the highest FAME yield of ~ 30% was obtained at 63°C after 180 minutes. However, further studies are required for in-depth understanding of the activity and kinetics of the catalyst for biodiesel production from WCO.