Kinetics of free fatty acids esterification in waste frying oil using novel carbon-based acid heterogeneous catalyst derived from Amazonian Açaí seeds – Role of experimental conditions on a simpler pseudo first-order reaction mechanism
Danilo Gualberto Zavarize, Gláucia Eliza Gama Vieira, Jorge Diniz de Oliveira
Abstract
This study reports the kinetics of free fatty acids esterification in waste frying oil, based on a simpler non-conventional pseudo first-order homogeneous reaction mechanism using a highly-efficient acid heterogeneous catalyst derived from seeds of Açaí (Euterpe oleracea Mart.), subjected to changes in temperature, catalyst dosage, MeOH:Oil ratio, and stirring speed. Statistical analyses revealed significant effects all four conditions (p < .05) on the reaction's apparent rate constant (k1) over their different pre-defined levels. Reaction mechanism was inferred to be fundamentally acid ionic exchanges with the oil/water film on catalyst's surface, neglecting kinetically controlled liquid-to-liquid splitting and autocatalyzed esterification.