Prediction of calcination and sulphation along the sorbent particle trajectories for desulphurisation in coal-fired furnace

Abstract

The furnace sorbent injection is analysed numerically, focusing on its behaviour, in order to estimate CaCO3 sorbent utilisation. Comprehensive presentation of numerical results and profound analysis are provided to better understand the process under realistic conditions. The boiler load reduction, varied between 70 and 100%, did not disturb the processes in furnace. Insight into individual trajectories and their overall sulphation reveal that reduced load, in these cases, yield somewhat better SO2 reduction. Reactivity of the sorbent particles was better with the boiler load reduction, especially for particles passing near the flame core. The calcination and sulphation of sorbent particles increase with the boiler load decrease, due to the combined influence of extended particle residence time and more favourable reaction conditions. Thus the boiler load reduction can lead to better particle utilisation and higher SO2 capture. The conclusions are limited to the case-study conditions and impose the need for further investigation.