Abstract:
Comparison of the biodiesel production from Coconut (Cocos nucifera) oil was carried out using both the two stage method (esterification followed by transesterification) (Ac-Bs-M) and the single stage base-transesterification method (Ss-M). For the two stage biodiesel production, the esterification was carried out using conc. H2SO4. The reaction was carried out for a total stirring time of 2 h and methanol quantity of 8% by volume of oil at a constant low stirring speed. The transesterification was carried out after 8 h of the esterification using potassium methoxide (0.65%) as catalyst at 60°C and reaction time of 2½ h also at a constant low stirring speed. The single stage base-transesterification was carried out at catalyst concentration of 0.7%, reaction temperature of 45°C and reaction time of 45 min while keeping the speed of stirring constant. The methyl ester obtained from the two systems was purified by washing with water severally to obtain the relatively pure biodiesel. They were dried using solar dryer for a period of four (4) days. They were also analyzed according to ASTM D 6751-20 for some parameters including, free fatty acid (FFA), flash point, cloud point, pour point, ash content, moisture content, specific gravity and kinematic viscosity. The results of the parameters analyzed were comparable to International standards of biodiesel. The results of the study showed that the volumetric yield obtained from the two-stage method was 50% while that obtained from the single stage method was 82%. The results indicate that for this oil type with low free fatty acid, the two stage method is not the appropriate method for converting the coconut oil to biodiesel.
