Influence of feedstock and operational conditions on bio-chars derived from the pyrolysis of selected biomasses

Nine bio-chars were produced by pyrolysis of three different types of biomass, representative of softwoodconifer (black pine) and hardwood-deciduous (black poplar and willow) wood. Pyrolysis was carried out in a macro TGA at 400, 550 and 650 °C on each biomass, following decorticatication and chopping. Porosity of these bio-chars was studied by means of BET analysis, Hg porosimeter and electron microscopy, while the retention and release capacity of ions was quantified via the cation exchange capacity (CEC) that is usually determined for the soils. It has been observed that the adsorption properties of the chars increase with pyrolysis temperatures, with a more pronounced effect on softwood than hardwood species.