Synthesis of Alumina Based Alkaline Catalyst for Biodiesel-Derived Glycerol to Polyglycerol

Biodiesel which comes from pure renewable resources provide an alternative fuel option for future. The rapid growth of the biodiesel industry will result in overproduction of less value glycerol and create a superfluity of this impure by-product. The synthesis of alkaline alumina catalyst for polyglycerol production via solvent free base-catalyzed etherification of low value glycerol is reported. The etherification of biodiesel derived glycerol to polyglycerol was studied in a heterogeneous catalysis under solvent free system, using alkalines over γ – alumina catalysts. All the catalysts were prepared by incipient-wetness impregnation of an aqueous solution of alkaline compounds on γ – alumina as a support. The effects of alkaline compound, reaction temperature, catalyst amount, and reaction time in conversion of glycerol to polyglycerol were investigated. The catalyst with potassium loaded on γ -alumina gave the highest basicity and the best catalytic activity for this reaction. The highest glycerol conversion into polyglycerol production was obtained with high yield 79.5% over prepared catalyst respectively. Industrially, the findings attained in this study might contribute towards promoting the biodiesel industry through utilization of its by-products.