Open AccessProduction of biodiesel by esterification and transesterification from waste cooking oils
Author(s) -
Elsy Arenas,
Aidin Urribarrí,
John Sánchez,
Marisela Rincón,
Karina Martínez,
Eduardo González,
Cateryna Aiello
Publication year - 2020
Publication title -
revista de la facultad de agronomía
Language(s) - English
Resource type - Journals
eISSN - 2477-9407
pISSN - 0378-7818
DOI - 10.47280/revfacagron(luz).v38.n1.06
Subject(s) - transesterification , chemistry , biodiesel , organic chemistry , methanol , biodiesel production , catalysis
Large quantities of used vegetable oils (AVUs) are generated annually, as a result of food preparation, which can cause contamination of waters and soils, if they are not disposed of properly, but in turn have great potential in the production of biodiesel. In this work, the AVU collected from fast food establishments were subjected to an esterification pretreatment, varying the reaction conditions, molar ratio, catalyst concentration and time, to decrease the content of free fatty acids generated in the frying processes; after an alkaline transesterification. The initial acidity of the AVUs (10,08 ± 0,22 %) was found to drop below 1 % during esterification at 60 °C and 100 rpm, with RMAVU:MeOH of 1: 7 and HCl concentration of 0.3 % v/v, with a conversion of free fatty acids (FFA) to methyl esters of 94.48 and 98.61 % for reaction times of 4 and 6 hours, respectively. The previously esterified AVUs were subjected to a transesterification process with KOH as a catalyst in the presence of methanol, at 60 °C and 100 rpm, finding that the biodiesel produced was a mixture composed of the methyl esters of linoleic acids (57 %), palmitic (14 %), oleic (22 %), stearic (4 %) and elaidic (3 %). The highest concentration of methyl esters (93,797 ± 0.685 g.L-1) was obtained when using the esterified AVU during 6 hours of reaction. FTIR spectra confirmed the conversion of fatty acids to methyl esters, so this product could be used as a biofuel.