Analysis of sewage sludge ashes from air and oxy-fuel combustion in a circulating fluidized-bed

Abstract

The ashes from sewage sludge combustion in air versus O2/CO2 atmospheres with oxygen concentrations in the range of 21-40% vol. at temperature of 850°C in a 12 kW bench-scale CFB combustor were characterised. The chemical and phase composition of ashes were studied by XRF and XRD. The morphology of studied ashes were examined by SEM method. The slagging and fouling indices were calculated to study the deposition tendencies of ash. The thermal behaviour of ashes was studied by TG-DSC techniques, focusing on the mass loss and thermic effects with the increasing of temperature up to 1200°C.