number and yield were 673% and 53%, respectively, while at 600◦ C, they were 946% and 43%. The iodine number is best described as the fourth-order polynomial with an R2 value of 0.99. The yield decreased exponentially with an R2 value of 0.97 up to a temperature of 700◦ C. The y error bars have also been shown in the figure expressing potential error amounts relative to each data marker in the data series. In the figure, 5% positive and negative potential error amounts were shown in the results of the experiments. The time of activation that determines the process duration was an important variable. The e2ect of time on activation and yield is shown in Fig. 2. Activation was found to increase rapidly with time for the first 30 min, reaching a maximum value around 50 min. Further increase in time led to a loss of activation, which might be due to the depletion of surface per unit weight of the activated charcoal. The increasing tendency of degree of activation appeared to be a polynomial of order four having an R2 value of 0.99. Yield decreased with increase in time. It is best described