Obtaining butyl levulinate from fructose over acid solid catalysts with water removal

Abstract

Fossil resources are running out on our planet, while environment and sustainability concerns are gaining importance year by year. New targets have been settled in Europe in order to reduce emission of pollutants and particles to the atmosphere. In order to fulfill with these targets, a reformulation in transport fuels is needed since they are the principals originators. Butyl levulinate is an ester which seems to be a potential additive in biodiesel blends. Its properties as boil point, viscosity or miscibility in water and in diesel, make it a suitable candidate. Its presence in biodiesel blends reduce significantly the emissions, and in addition, improve their cold flow properties. Synthesis of butyl levulinate is obtained through esterification of levuinic acid with butanol, which can be achieved from dehydration of monosaccharides like fructose or glucose, from alcoholysis of furfural alcohol or from levulinic acid. Levulinic acid is a platform molecule which have a significant interest in industry. Is obtained by Biofine process, in which biomass is used as raw material. Nowadays, tarting from biomass is interesting. This is why it is being studied the feasibility of butyl levulinate synthesis from fructose or glucose. Previous studies have been made in order to evaluate the type of catalyst that can enhance the most butyl levulinate formation, with a temperatures range between 100 and 130 ºC and in atmospheric pressure. In this study, same conditions were settled in order to test which proportions between fructose and butanol, and which quantity of catalyst, can obtain the best results. It has been observed the importance that water presence in initial mixture have regarding humins formation. Reducing the viscosity of the initial mixture enhances butyl levulinate formation and decreases humins presence. Molar rations between butanol and fructose around 6 gave better results than the others, and excepting one case, yields increased according with catalyst dosage