High-Performance of Catalyst Synthesized from Waste Can Aluminum and Rice Husk Silica for Conversion Coconut Oil into Biodiesel

The development of biodiesel is one of the extensive research projects that have been undertaken in response to the diminishing fossil energy reserves, air pollution, and climate change. This work introduces catalysts synthesized from waste can aluminum and rice husk silica (AS) with Si/Al molar ratios of 10, 20, and 30. The catalysts were synthesized by the hydrothermal process in an autoclave at 100 ºC for 24 h, followed by calcined at 550 °C for 5 h, and evaluated as catalysts for biodiesel (fatty acid methyl esters, FAMEs) production from coconut oil. The AS-10 catalyst demonstrates highly performance, with 99.57% yield under operational conditions (10 wt.% catalyst, 1:2 oil-to-methanol ratio, 60 °C, 6 h). In addition, the catalyst has 99.69% FAME selective, with biodiesel that most closely matched the fatty acid composition of coconut oil. For the characteristic, this catalyst exhibits amorphous phase and a small average crystal size, as demonstrated by the XRD patterns and SEM images. The FTIR spectra after pyridine absorption qualitatively shows the presence of Brønsted (1546 cm-1) and Lewis (1457 cm-1) acid sites on this catalyst. High-performance catalytic activity is usually attributed to these characteristics, which may be able to enhance the adsorptivity towards triglycerides of coconut oil. Hence, these findings suggest the prospective use of the catalyst in the biodiesel production derived from coconut oil.