A segmental analysis of pyrolysis of woody biomass

The study aims to examine the physicochemical properties of biochar obtained at different temperatures of woody biomass pyrolysis. The method proposed and tested in the paper allows terminating pyrolysis in a given stage and investigating the characteristics of biochar, which is a solid intermediate. The study employs thermogravimetric analysis combined with mass spectrometry to examine and compare characteristics of biochar, obtained at different temperatures (200, 250, 275, 300, 325, 350, 375, 400, and 500 °C), along with levoglucosan, cellulose, and lignin. Semi-quantitative analysis of gaseous products made it possible to determine the composition of the compounds released during the thermochemical conversion of the samples under study. Biochar properties change dramatically during pyrolysis at temperatures of 350 °C and above. Changes in the surface morphology of biochar were studied using scanning electron microscopy.