ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Optimization of process conditions for biodiesel production over CaO–Al2O3/ZrO2 catalyst using response surface methodology
Mohammad Hojjat, Hamed Nayebzadeh, Mahmoodreza Khadangi-Mahrood, and Behgam Rahmani-Vahid
Department of Chemical Engineering, Quchan Branch, Islamic Azad University, Quchan, Iran
Abstract: CaO–Al2O3/ZrO2 mixed oxide catalyst was prepared using free-solvent method. The catalyst was characterized using X-ray diffraction, BET surface area, acidity index (obtained by titration method), and scanning electron microscopy (SEM). With calcium aluminate and calcium zirconate been successfully formed, the mix exhibited small crystal size, high acidity, and large surface area, pore size, and pore volume, making it a catalyst of choice for biodiesel production. The activity of catalyst was evaluated in the course of esterification of oleic acid as well as transesterification of waste cooking oil (WCO) into biodiesel. Based on a four-variable central composite design (CCD), response surface methodology (RSM) was used to optimize effective variables on oleic acid conversion. The optimum yield of 94.68% was obtained at the following set of optimum conditions: reaction temperature of 120 °C, methanol/oleic acid molar ratio of 15.64, catalyst concentration of 2.94 wt%, and reaction time of 4 h; the result was in excellent agreement with the predicted values. Furthermore, under the optimum conditions, the catalyst succeeded to convert 93.48% of WCO into biodiesel.
Keywords: Calcium zirconate; Calcium aluminate; Esterification of oleic acid; Transesterification of waste cooking oil (WCO); Response surface methodology (RSM)
Full paper is available at www.springerlink.com.
Chemical Papers 71 (3) 689–698 (2017)
Sunday, September 26, 2021