Fly ash as a new versatile acid-base catalyst for biodiesel production

Munoz, Robinson; Gonzalez, Aixa; Valdebenito, Fabiola; Ciudad, Gustavo; Navia, Rodrigo; Pecchi, Gina; Azocar, Laura


The production of fatty acid methyl esters (FAME) from waste frying oil (WFO) was studied using fly ash as received as a heterogeneous catalyst. The fly ash used in this research had a high content of both CaO and SO3, two compounds that have been previously proposed as catalysts in FAME production. The study was carried out on the basis of a response surface methodology (RSM). The model generated by RSM predicted as optimal conditions to obtain a 100% FAME yield at a methanol-to-oil molar ratio of 3.1:1, 11.2 (wt.% based on oil weight) fly ash and a temperature of 59 degrees C with agitation at 245 rpm and 6 h of reaction time. Additional experiments comparing anhydrous with aqueous medium showed that fly ash presented a high catalytic capacity to transform free fatty acids (FFA) into FAME through consecutive hydrolysis and esterification processes (hydroesterification) compared with that associated with the transesterification mechanism. According to the results, the fly ash used in this study would act as a multipurpose or "versatile" catalyst due to its chemical composition with constituents that act as acidic and basic catalysts, therefore, catalyzing the transesterification and hydroesterification reactions simultaneously and increasing the conversion yields of FAME. (C) 2020 Elsevier Ltd. All rights reserved.

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Título según WOS: Fly ash as a new versatile acid-base catalyst for biodiesel production
Título de la Revista: RENEWABLE ENERGY
Volumen: 162
Fecha de publicación: 2020
Página de inicio: 1931
Página final: 1939


Notas: ISI