No.36 Vaporization and Coagulation of Metals upon the Recirculation of Flue Gas Impurities(H2O, HCl and SO2)During Victorian Brown Coal Oxy-fuel Combustion

抄録

Oxy-fuel combustion of a Victorian brown coal of Australia was carried out at 1000°C to experimentally quantify the vaporisation of organically bound metals and the coagulation of corresponding metallic vapors as a function of the concentration of gaseous impurities including H_2O, HCl and SO_2 in 27% O_2 balanced with CO_2. The results indicate that, organically bound metals are highly sensitive to the changes to the loading of gas impurities during lignite combustion. HCl re-circulation is the most crucial factor promoting the vaporisation of metals via chlorination. Re-circulation of SO_2 affected the vaporisation of Na via changing the SO_2/HCl ratio in flue gas. Co-existence of steam with HCl and SO_2 is more favorable for the conversion of chlorides into molten alumino-silicates rather than sulfate droplet, which however should be cautioned, as its side effect on coal oxidation rate would be significantly intensified.