Hydrothermal synthesis of calcium methoxide nano-catalyst for palm oil based biolubricant production

The present work investigated the biolubricant production from palm oil-based methyl ester over calcium methoxide nanocatalyst. The hydrothermal method was employed in this work to prepare nano-calcium methoxide. The difference of hydrothermal synthesis time influenced on the catalytic characteristics and performances was studied. The catalytic activity showed a significant dependence on the catalyst's basic sites and particle size, achieving a palm oil methyl ester conversion of 78–89 % and a selectivity of 62–80 % for biolubricant production. The calcium methoxide with a hydrothermal synthesis time of 6 h exhibited superior catalytic activity to the other catalysts as a result of its small particle size and high basicity. Additionally, the calcium methoxide catalyst apparently showed good stability and reutilization, with palm oil methyl ester conversion of 85 % after use for 6 consecutive cycles. The physicochemical properties of the obtained biolubricant aligned closely the ISO VG 46 mineral oil, especially regarding viscosity and flash point. However, due to its high pour point, the obtained biolubricant may be most suitable for applications in tropical climates without winter conditions