Investigating the Influence of Reaction Conditions and the Properties of Ceria for the Valorisation of Glycerol

Abstract

The reaction of aqueous glycerol over a series of ceria catalysts is investigated, to produce bio-renewable methanol. Product distributions were greatly influenced by the reaction temperature and catalyst contact time. Glycerol conversion of 21% was achieved for a 50 wt.% glycerol solution, over CeO2 (8 m2 g−1) at 320 °C. The carbon mass balance was >99 % and the main product was hydroxyacetone. In contrast, at 440 °C the conversion and carbon mass balance were >99.9 % and 76 % respectively. Acetaldehyde and methanol were the major products at this higher temperature, as both can be formed from hydroxyacetone. The space-time yield (STY) of methanol at 320 °C and 440 °C was 15.2 and 145 gMeOH kgcat−1 h−1 respectively. Fresh CeO2 was prepared and calcined at different temperatures, the textural properties were determined and their influence on the product distribution at iso-conversion and constant bed surface area was investigated. No obvious differences to the glycerol conversion or product selectivity were noted. Hence, we conclude that the surface area of the CeO2 does not appear to influence the reaction selectivity to methanol and other products formed from the conversion of glycerol.