Characterization of Dolomite Promoted by NaAlO2 and Application as Catalyst in Transesterification by Response Surface Methodology

Abstract

AbstractThe effective heterogeneous base catalysts are synthesized to intensify the catalytic capacity of dolomite via the wet impregnation method with NaAlO2. Compared with the calcined natural dolomite, the catalyst promoted by 10% NaAlO2 possesses the higher basic density and more developed mesoporous structure, where the better catalytic activity is performed to transesterify palm oil with methanol. Response surface methodology with Box‐Behnken Design (RSM‐BBD) is used to investigate the combined effects of the catalyst loaded amount, molar ratio of methanol to oil, transesterification temperature and duration on biodiesel yield. Results show that the highest yield of 99.27% is achieved with the 5.30 wt.% catalyst loaded amount and 12.39 molar ratio of methanol to oil at 65.26 °C for 2.11 h. The catalyst shows superior stability and efficiency of 89.92% is achieved for the fifth reused cycle, where for the pure calcined dolomite it is 77.58%. Also, the physicochemical indices of the purified transesterification product are in accordance with ASTM D6751 standard.