New insights on the structural evolution of biomass char upon pyrolysis as revealed by the Raman spectroscopy and elemental analysis

Abstract The influence of pyrolysis conditions on the structure properties and chemical composition of biomass chars was examined. The Raman spectroscopy ID/IG and IV/ID parameters were found to be correlated for pyrolysis temperatures higher than 600 °C. Furthermore, a correlation between IV/ID and the atomic ratio (O+H)/C was identified. These findings would corroborate the assumption that the large carbonaceous structures having defects (D band) would probably form from the condensation of the small amorphous ones (V region). The condensation of these small structures into larger ones would be accompanied by the release of H and O atoms into the gas phase.