Interactions of CO, HCl, and SOx in pulverised coal flames

The effect of HCl and SO2 on CO oxidation in pulverised coal flames was investigated experimentally and kinetically in an entrained flow combustion reactor. Two bituminous coals (German ‘Goettelborn’ and a Polish coal) were used as fuels with a feeding rate of 1 or 1.5 kg/h. HCl or SO2 is introduced into the reactor premixed with the primary air. Experimental results indicate that HCl addition may inhibit CO oxidation in coal flames and increases CO emission. Reducing temperature in the reactor will enhance the inhibitory effect of HCl on CO oxidation. The measured CO profiles along the reactor height clearly show that the addition of HCl may inhibit CO oxidation. In the experimental range of SO2 addition, the inhibiting effect of SO2 on CO oxidation is less significant than HCl. A detailed kinetic mechanism is used to model the reactions, and the controlling reactions are analysed.