Experimental determination of reaction kinetics for the release of chlorine and sulfur species and for the conversion of these species in the gas phase
Sulfur and chlorine present in coals can form various corrosive combustion products. Due to the removal of nitrogen and flue gas recirculation, oxy-fuel combustion entails higher concentration of these corrosive (and all other) combustion gases. In Oxyflame subproject A3, models for the prediction of sulfur and chlorine species are developed.
Experiments are performed with an entrained flow reactor in which pulverized coal is heated up to target temperature almost immediately, achieving heating rates equivalent to large-scale boilers. The reaction progress is analyzed by taking gas and solid samples after different residence times. Kinetics are determined using thermogravimetric analysis.
Global reaction mechanisms for the release of chlorine and sulfur species during pyrolysis and char burnout will be derived from the experimental data. The influence of coal type, heating rate, temperature and gas atmosphere (conventional and oxy-fuel combustion) on species release will be evaluated.