Characterization of residues and evaluation of the physico chemical properties of soybean biodiesel and biodiesel: Diesel blends in different storage conditions

Abstract In biodiesel, long chain methyl esters crystallize at very low temperatures, forming paraffin crystals that clump together and clog fuel filters, preventing engine operation. When the fuel is at high temperatures and in the presence of oxygen from the air, chemical changes may occur, forming insoluble compounds in the fuel itself. This work followed the evolution of deposits and enhancers formation in biodiesel samples and their mixtures with diesel. Thus, samples of pure biodiesel mixed with diesel were stored under two temperature conditions, 30 °C and 4 °C–10 °C, for a period of 12 months. The results indicate that the residue formation in soybean biodiesel was intensified by the low temperature, time and presence of dissolved water, being the monoglycerides the main inducers.