The trans-esterification reaction was carried out in a laboratory glass reactor that was placed on a hot plate with a magnetic stirrer to produce castor oil biodiesel. In the trans-esterification processes, catalyst loadings ranging from 3% to 6% weight (relative to oil) were used, with methanol to oil ratios ranging from 6:1 to 10:1. The reaction time and temperature range from 1 to 4 hours and 45 to 60 o C. A separating funnel was then used to separate the fatty acid methyl esters from the glycerol. The yield of the biodiesel produced was then calculated using Equation ( )