Solid catalysts obtained from wastes for FAME production using mixtures of refined palm oil and waste cooking oils

More than 95% of biodiesel production feedstocks come from edible oils, however it may cause some problems such as the competition of land use between food production and biodiesel production. The waste cooking oils (WCO) are an alternative feedstock for biodiesel production: its usage reduces significantly the cost of biodiesel production and has environmental benefits, e.g., a waste recovery instead of its elimination. This work aims to produce a low-cost efficient solid catalyst for fatty acid methyl esters (FAME) production using mixtures of refined palm oil (RPO) and WCO. Four low cost catalysts were prepared (biomass fly ashes, natural dolomite rock, chicken eggshells and polyethylene terephthalate - PET), characterized (by SEM, EDX, XRD, BET, FT-IR and Hammett indicators) and tested regarding their performance in FAME production. The maximum yield of FAME achieved was around 96% wt. for biomass fly ashes catalyst at 60 degrees C, 9:1 (mol/mol) of methanol to oil mixture, 10%wt. catalyst to oil mixture, over 180 min in batch reactor. The results point out for promising bifunctional catalysts able to achieve also conversion of free fatty acids up to 100% using mixtures of RPO and WCO. (C) 2019 Elsevier Ltd. All rights reserved.