Possibility of Using Commercial Hydrated Lime as a Catalyst for Rapeseed Oil Methanolysis

In this research, the possibility of using Ca(OH)2 in the form of commercial hydrated lime as a catalyst for the methanolysis of refined rapeseed oil was evaluated. Characterization of unused catalyst was performed by SEM-EDS, laser diffraction, XRF, BET, XRD and TG/DTG methods, and vegetable oil was analyzed for physicochemical characteristics. Within methanolysis, the effects of catalyst loading, reaction temperature and reaction time on methyl ester yield, density and viscosity of biodiesel, as well as the possibility of catalyst reuse were investigated. The obtained results showed that hydrated lime is an efficient catalyst for transesterification of vegetable oil, whereby the use of 3 wt% of catalyst relative to oil weight, at temperature 60℃ and mixing rate 1000 rpm after 120 min of transesterification reaction achieved a yield of methyl esters 98.76%. With three reuses of hydrated lime, without intermediate washing and regeneration procedures, the yield of rapeseed oil methyl ester remained above 90%.