Język
EN
Treść
This paper is focused on the thermal characterisation of biomass ashes especially the mineral phase transformation. Ash generated during combustion (with a high alkali metal concentration) can deposit and consequently cause serious operating problems such as slagging, fouling and metal surface corrosion thus limiting heat transfer. Four biomass ashes with a different origin were investigated. The chemical composition of the mineral matter of ashes varied between the samples, but CaO, SiO2, K2O, MgO, P2O5 and Al2O3 are the main compounds of the ashes. The thermal behaviour of the ashes was studied using TG-DSC (mass loss. temperature peaks enthalpy associated with thermal effects) and Ash Fusion Temperatures (AFTs, deformation, softening, hemisphere, flow temperatures) techniques. In order to describe and understand the mineral matter transformation at high temperatures the FactSage Thermodynamics Model was used. FactSage calculations made it possible to predict the chemical composition in equilibrium, showed the amount of liquid slag and solid phases, and gave information about the slagging properties of ashes.
