Insights of alkali metal ions role in steam assisted pyrolysis of xylan

The presence of metals ions in biomass strongly affects pyrolysis product distribution promoting the formation of gaseous species and char at the expense of liquid fraction yield [1]. The role of inorganics on biomass components pyrolysis is far to be completely understood and deserves further experimental studies. The most abundant literature data are available only on the effect of metals ions on cellulose pyrolysis and hypotheses on decomposition mechanisms have been also formulated [2,3]. On the contrary only few works reported about the metal ions effect on the pyrolysis of the remaining biomass component, namely hemicellulose and lignin [4,5]. In the present paper the influence of metal ions on hemicellulose pyrolysis has been studied choosing commercial xylan (beechwood xylan, X4252 from Sigma Aldrich) as reference compound.