Etherification of glycerol for improved production of oxygenates

Various resin and zeolite based catalysts are prepared, characterized and evaluated for their catalytic performance towards the etherification of glycerol with tertiary butyl alcohol. Resin based catalysts exhibited higher glycerol conversions and ether selectivities at relatively lower reaction temperature (75 degrees C) than the zeolite based catalysts (90 degrees to 110 degrees C) but the zeolite based catalysts performed better in terms of stability in activity to produce high amounts of di-tertiary butyl (DTBG) and tri-tertiary butyl ether (TTBG) of glycerol (oxygenate stock). Though acidity is important for the etherification reaction, the zeolites exhibiting better porosity rather than acidity could yield higher oxygenate. The presence of intercrystalline meso-pores in N-BEA further improved the oxygenate production and time-on-stream activity of the catalyst. At optimized catalyst parameters and reaction conditions, Nano-beta (N-BEA) zeolite catalyst exhibited above 95% conversion of glycerol with more than 45% and 54% selectivities to DTBG and TTBG, which are potential blending stocks for diesel. (C) 2012 Elsevier Ltd. All rights reserved.