Chinese Journal of Catalysis ›› 2017, Vol. 38 ›› Issue (10): 1697-1710.DOI: 10.1016/S1872-2067(17)62891-2

• Article • Previous Articles     Next Articles

Coke-tolerant SiW20-Al/Zr10 catalyst for glycerol dehydration to acrolein

Amin Talebian-Kiakalaieh, Nor Aishah Saidina Amin   

  1. Chemical Reaction Engineering Group (CREG), Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia (UTM), Skudai 81310, Johor, Malaysia
  • Received:2017-03-24 Revised:2017-06-30 Online:2017-10-18 Published:2017-10-28
  • Contact: 10.1016/S1872-2067(17)62891-2

Abstract:

Glycerol dehydration to acrolein over a series of supported silicotungstic acid catalysts (SiWx-Al/Zry) was investigated. Characterization results showed that the final catalyst had high thermal stability, a large pore diameter, strong Lewis acidic sites, and a large specific surface area. X-ray photoelectron survey spectra clearly showed peaks attributable to W (W 4f = 35.8 eV), Al2O3 (Al 2p = 74.9 eV), and ZrO2 (Zr 3d = 182.8 eV). The highest acrolein selectivity achieved was 87.3% at 97% glycerol conversion over the SiW20-Al/Zr10 catalyst. The prepared catalysts were highly active and selective for acrolein formation even after 40 h because of the presence of high concentrations of Lewis acidic sites, which significantly reduced the amount of coke on the catalyst surface. Response surface methodology optimization showed that 87.7% acrolein selectivity at 97.0% glycerol conversion could be obtained under the following optimal reaction conditions: 0.5 wt% catalyst, reaction temperature 300 ℃, and feed glycerol concentration 10 wt%. Evaluation of a mass-transfer-limited regime showed the absence of internal and external diffusions over pellets of diameter dP<20 μm. These results show that glycerol dehydration over a strong Lewis acid catalyst is a promising method for acrolein production.

Key words: Glycerol, Dehydration, Acrolein, Heterogeneous catalysis, Heteropoly acid