Pre-Treatment of Waste Frying Oils for Biodiesel Production

Abstract

Synthesis of biodiesel is a strategic step in overcoming energy scarcity and the environmental degradationcaused by the continuous use of the petroleum based energy. Biodiesel as an alternative fuel for diesel engine isproduced from renewable resources such as vegetable oils and animal fats. The main obstacle in the biodieselproduction is the high price of the raw materials, resulting in the price of biodiesel is not competitive comparedto the petroleum diesel. Therefore, the use of waste frying oils (WFO) is one way to reduce the cost of biodieselproduction, because of its availability and low price. In the present work, WFO from California Fried chicken(CFC) restaurants in Surabaya were used as feed stock for the biodiesel production. The experiments wereconducted using three steps of processes: pre-treatment of WFO, preparation of alumina based compositecatalyst CaO/KI/γ-Al2O3 and transesterification of treated WFO. WFO was treated by several types and variousamounts of activated adsobents. The treated WFO was transesterified in three neck glass batch reactor withrefluxed methanol using CaO/KI/γ-Al2O3. The results reveal that the best method for treating WFO is using 7.5%(wt. % to WFO) of coconut coir. Alumina based composite catalyst CaO/KI/γ-Al2O3 was very promising fortransesterification of WFO into biodiesel. The yield of biodiesel was 83% and obtained at 65ºC, 5 h of reactiontime, 1:18 of molar ratio WFO to methanol and 6% amount of catalyst.