Conversion of Biodiesel By-Product Glycerol to Fuel Ethers over Different Solid Acid Catalysts

In this study, the etherification reaction of glycerol (G) with tert-butyl alcohol (TBA) was investigated for the production of high quality transportation fuel additives. The reaction was carried out in liquid phase, in a continuous flow reactor in the presence of various solid acid catalysts. Activities of acidic resin catalysts, such as Amberlyst-15 (A-15), Amberlyst-16 (A-16) and Amberlyst-35 (A-35), Nafion-SAC-13 and gamma-alumina were compared. Significant increase in conversion was observed with an increase in temperature. Amberlyst 15 showed the highest activity at about 110 degrees C, giving glycerol conversion values of about 0.5 at a space time of 18 g cm(-3) s. However, A-16 gave higher di-ether selectivity values. Nafion-SAC-13 showed activity at higher temperatures, while the activity of gamma-alumina was very low, even at 400 degrees C.