Fast pyrolysis of heavy metal contaminated willow: Influence of the plant part

Fast pyrolysis of heavy metal contaminated willow, with high concentrations of Cd, Cu, Pb and Zn, resulting from phytoremediation, is investigated. The distribution of the heavy metals depends on the plant part (leaves and branches). Nevertheless, their individual pyrolysis fractions (at an operational temperature of 623 K), i.e., bio-oil/tar and gas, are both heavy metal free. Some small differences in the kind and amounts of the organic compounds are found in the bio-oil and gaseous fraction. In view of practical considerations leaves and branches should nevertheless be pyrolysed simultaneously. The use of hyphenated thermal analytical techniques allows obtaining more detailed information on the compositional features of the pyrolysis fraction.