Otimização estatística da síntese de biodiselpor transesterificação e hidroesterificação metílicas e etílicas com o uso de óleo residual de fritura.

Abstract

Biodiesel represents an essential alternative to meet the growing energy demand of modern society in a sustainable way. The objective of this study was to optimize the synthesis of biodiesel from residual frying oils in methyl and ethylic routes by alkaline transesterification and hydroesterification. The raw material used was the residual frying oil, collected at the II campus of the Federal University of the Triângulo Mineiro (UFTM). The routes were defined by the Central Compound Planning (CCP), which optimized the variables; mass of sodium hydroxide, reaction time and the masses of ethanol and methanol. Subsequently, the samples were characterized, analyzing the parameters; specific mass, kinematic viscosity, freezing point, peroxide value and iodine value. The analyzes of the optimized biodiesel were within the limits established by the National Agency of Petroleum, Natural Gas and Biofuels (ANP). The mass yields obtained for the methyl and ethyl transesterification routes were in the range of 95 and 93%, respectively, for methyl and ethyl hydroesterification yields were 92 and 91%, respectively. The yields obtained in the gas chromatograph (contents of methyl and ethyl esters) were higher than 97% for transesterification and hydroesterification. This methodology favors the expansion of use of biodiesel of residual origins as an alternative to petroleum based fuels (diesel oil), as well as providing an environmentally adequate final disposal for residual frying oils.