Biodiesel production from waste cooking oil using KOH/HY-type nano-catalyst derived from silica sand

Abstract

The present study aimed to synthesize a Y-nanozeolite catalyst using the hydrothermal method and Iraqi sand-derived silica as a low-cost and readily available raw material. The catalyst was tested before and after loading with potassium hydroxide (KOH). The experiments were conducted in a batch reactor under different temperatures (40, 50, and 60 °C) and a 3-h reaction time, using the prepared Y-catalyst with three different particle sizes (75, 600, and 1000 μm). The results showed that increasing the temperature and/or reaction time generally resulted in increased conversion and yield when the catalyst was unpromoted with KOH, reaching a range of 55.56% and 33.33%, respectively. However, a significant increase in the conversion and yield was observed after promoting the catalyst with 10% KOH molecules. The optimal conditions for achieving the highest conversion and yield of biodiesel were determined to be 86.67% and 82.22%, respectively. These conditions involved a temperature of 60 °C, a reaction time of 2 h, and the use of a catalyst with a particle size of 75 μm loaded with 10% KOH. The use of a heterogeneous catalyst loaded with the base in a low percentage helps to dispense with the use of homogeneous catalysts with a high percentage of bases.