Effect of using microwaves for catalysts preparation on the catalytic acetalization of glycerol with furfural to obtain fuel additives

Abstract

The effect of using microwaves or conventional heating for synthesizing/modifying several acid micro- and mesoporous materials have been studied by testing them as catalysts for the acetalization of glycerol with furfural to obtain 1,3-dioxane and 1,3-dioxolane (fuel additives). Microwaves allowed us the incorporation of higher amounts of sulfonic groups in SBA-15 and montmorillonite MK-10 catalysts whereas for zeolite samples the differences were not significant. The catalysts prepared/modified with microwaves led to higher conversion but slight lower selectivity to the desired products than those prepared by conventional heating. Sulfonated montmorillonite MK-10 catalysts showed high conversion (62-68%) and the highest selectivity values to the desired products (72-86%). This has been related to the higher surface density of Brønsted acid sites observed for these catalysts. The presence of Lewis acid centres in the ReOx/hectorite catalyst increased the formatron od dioxane.