Box–Behnken optimization of biodiesel production using trisodium phosphate catalyst from monazite ore processes

Abstract

AbstractTrisodium phosphate (TSP) is a non‐toxic waste obtained from alkaline cracking as part of the processing of monazite ore. After simple purification, TSP can be utilized in many applications; however, it is used as a catalyst in this study. It is characterized using Thermogravimetric analysis , X‐ray diffraction analysis, Brunauer‐Emmett‐Teller, and Temperature‐programmed desorption of carbon dioxide and optimized in the transesterification reaction. After recrystallization and calcination at 350 °C for 0.5 h, the form of the TSP was tetragonal, with a 2.61 m2/g surface area and 537.4 x 10‐6 mol/g basic sites. Trisodium phosphate can therefore be utilized effectively as a solid base catalyst for the transesterification of palm oil. Three biodiesel production parameters were investigated: the methanol to oil molar ratio (6:1–24:1), catalyst concentration (1–10%), and reaction time (30 to 240 min). The experiments were designed using the Box–Behnken response surface method. As a result, the optimum conditions for biodiesel production are a 22:1 methanol to oil molar ratio, 4% catalyst concentration, and 200 min reaction time. The optimal fatty acid methyl ester (FAME) content is 99.79%, with an error between actual and predicted FAME of 0.21%. © 2023 Society of Industrial Chemistry and John Wiley & Sons Ltd.