A contribution to the study of kinetics of the transformation of fructose into butyl levulinate in aqueous media.

Abstract

The climate crisis has forced to accelerate the research of greener solutions to those already established in industry. In this search, alkyl levulinates have stood out due to their physicochemical properties and their low toxicity. These compounds have interesting applications in a variety of fields, but they mostly outstand as oxygenate additives for gasoline and diesel, improving their quality and reducing their pollution. Especially, it has generated a great deal of interest butyl levulinate, since it has demonstrated to improve cold flow properties, conductivity and lubricity, among other properties. Butyl levulinate can be obtained through an esterification of levulinic acid with 1-butanol in liquid phase. However, due to the difficulty of purifying the acid, is being studied its obtention from hexoses. Particularly, from fructose, since it has demonstrated to be the optimum route. The process of obtaining butyl levulinate from fructose consist of a reaction network, where the reactions are given in series-parallel and are the following: · Fructose dehydrates and forms 5-hydroximetil furfural (HMF). · HMF is rehydrated and are obtained levulinic and formic acids. · In parallel, HMF reacts with 1-butanol and gives 5-hydroxibutyl furfural (HBF). · Levulinic and formic acids react with 1-butanol and produce butyl levulinate (BL) and butyl formate (BF), respectively. · By thermal degradation of fructose and catalytic reaction of HMF, there is the undesired formation of humins. Despite being a field with numerous advances in the last times, most of them are limited on academic studies. Hence, the necessity of the search of kinetic models that describe the process, as a first step to design and optimize the process in industrial scale.