In this study, the esterification reaction of Oleic Acid with methanol on the Sulfonated Aluminum Silica (SAS) heterogeneous acidic catalyst will be examined. The research aims to evaluate the effect of different methanol/fatty acid mole ratios (9/1-21/1), catalyst amounts (10%-20%), and reaction times (3h-9h) on the reaction efficiency at 105°C with the help of Box Bhenkhen. The activity of the prepared catalysts will be evaluated by considering two different catalyst forms (powder, and structural). This study demonstrates that, according to ANOVA statistical results, reaction time has the most significant impact on conversion values in experiments conducted with powdered catalysts. As the reaction time increases, the conversion rates rise rapidly. Additionally, the amount of catalyst used has a direct effect, with the highest conversion rate achieved at an Alcohol/FFA ratio of 9/1. Furthermore, it was discovered that the conversion values of the reaction that occurred in the presence of structural catalysts are comparable to those of the powder form. Additionally, they did not require a separation step when using structured catalysts as opposed to powder catalysts.