Biodiesel synthesis via heterogeneous catalysis: investigation of the catalytic performance of CLV98/900 on quality and yield at different production scales

Abstract

This article investigated the obtaining of fatty acid alkyl esters (FAAE) from waste cooking oil (WCO) via heterogeneous catalysis, applying a catalyst based on mixed oxides (Na-FeAlO) from the red mud (RM) sintering process with sodium carbonate, which was called CLV98/900. The synthesized catalyst was characterized by thermogravimetric analysis, differential thermogravimetry and differential calorimetric analysis (TG/DTG and DSC), Raman spectroscopy, and specific surface area (BET). The influence of the operational parameters oil/alcohol molar ratio (1:15 and 1:45), reaction time (60, 120 and 180 min) and scale-up on the yield and conversion of the reaction into biodiesel produced were investigated. The catalyst characterization indicated an efficient microstructural transformation of the red mud, thermal stability at the study temperature of 70 ºC, and a mesoporous characteristic. The best yield and reaction conversion results were obtained with the parameters: oil/ethanol ratio of 1:15, 70 °C, 1% catalyst and 60 min, achieving yield and conversion of approximately 75%. The formation of biodiesel was confirmed by GC-MS analysis, reaching a maximum of 100% conversion to the lower phase obtained after the purification process. Therefore, CLV98/900 becomes a promising option when used as a catalyst in biodiesel production through the transesterification reaction of WCO.