Roles of K₂O on the CaO-ZnO Catalyst and Its Influence on Catalyst Basicity for Biodiesel Production

Abstract

Abstract. This research aimed to study the effect of K 2 O impregnation on the basicity of the CaO-ZnO catalyst and its effect on biodiesel production. The effect of mole ratio of CaO to ZnO catalyst and %wt K 2 O were also studied. The mole ratio of CaO to ZnO catalyst was varied at 1:1, 1:1.5, 1:2, 1:3, and 3:1, while the %wt K 2 O was varied at 1, 3, and 5 %. The catalyst basicity was determined by titration method. The basicity of the catalyst increased after the CaO-ZnO catalyst was impregnated with K 2 O in all mole ratios of CaO-ZnO catalyst. The addition of K 2 O as a promoter also increase the basicity. The highest basicity was obtained at the CaO-ZnO mole ratio of 3:1 and 5%wt K 2 O. The tranesterification process was carried out in a batch reactor at a methanol to oil mole ratio of 15:1, a reaction temperature of 60 o C, a reaction time of 4 h, and a catalyst loading of 5%wt oil. The FAME yields obtained were 41.33%. These results proved that K 2 O plays a role in enhancing the catalyst basicity. In addition, K 2 O also serves as a binding agent to improve the mechanical properties of the catalyst.

Mechanism of CaO catalyst deactivation with unconventional monitoring method for glycerol carbonate production via transesterification of glycerol with dimethyl carbonate

“…The catalyst 0.5 g was dissolved in 1 mL of a solution of Hammett indicator diluted in 20 mL methanol and stirred to equilibrate for 60 minutes. The basicity (mmol/g) was determined by titration with benzoic acid (0.02 mol/L anhydrous ethanol solution) until the color change back to the beginning colour 40,41 …”

“…The basicity (mmol/g) was determined by titration with benzoic acid (0.02 mol/L anhydrous ethanol solution) until the color change back to the beginning colour. 40,41 The morphology of the catalyst was examined by scanning electron microscope (SEM) measurements performed with MX2000s microscopy, which could produce a three-dimensional image representation.…”