Biochar from lab-scale pyrolysis: influence of feedstock and operational temperature

Abstract Biochar properties are highly dependent on the feedstock type and operational conditions during thermochemical processing, in particular slow pyrolysis. To clarify this aspect, nine biochars were produced by pyrolyzing a macro TGA at 400, 550, 650 °C three different decorticated chopped biomasses. The studied biomasses representative of conifer (black pine) deciduous (poplar willow) woods. surface area, size, shape pores investigated means nitrogen adsorption isotherm, Hg porosimetry, electron microscopy. results indicate that with high area can be obtained temperature, especially starting from pine feedstock. Regarding porosity, micro-pores (1–10 nm) not remarkably affected feedstocks, while macro-pores (> 10 strictly connected morphology wood. More than we found strong correlation between chemical composition (elemental FTIR) their retention release capacity ions (cation exchange capacity, CEC). trend CEC, determined via coupled approach spectrophotometric ion chromatography, reveals increase processing temperature has effect reducing number functional groups able exchanging cations equilibrium solution. This work represents step forward characterization char pyrolysis biomass thanks to development multi-technique allowing obtain structure-property biochars. Our experimental help optimization parameters used preparation these materials. Graphical abstract