The present work investigates the energy consumption and yield of the esterification reaction of free fatty acids (waste oil pretreatment) under a simultaneous water removal by adsorption. The reaction was performed under methanol, ethanol, and 1-propanol at the optimum reaction temperature of 100 degrees C. The higher boiling point temperature of 1-propanol reduced the energy requirement of the reaction by 36.3 and 34.4% compared to methanol and ethanol, respectively. Moreover, despite the higher reactivity associated with alcohols having lower carbon chains, the reaction yield was approximately 16.4% higher under 1-propanol than the other two alcohols. This can be ascribed to the ability to use higher amounts of 1-propanol while maintaining lower energy consumption. The results also indicated that the reaction at 100 degrees C under methanol and ethanol had a similar energy consumption and yield, favoring the use of the renewable ethanol over the widely used nonrenewable methanol. Finally, these findings highlight the importance of investigating the energy consumption of novel oil pretreatment processes and not solely focus on their ability to convert free fatty acids to biofuel.