CATALYSIS BY WATER-VAPOR OF THERMAL-DECOMPOSITION OF CALCIUM-CARBONATE

The rate of thermal decomposition of compacted spheres of calcium carb onate in the presence of water vapour has been measured over a range o f temperatures and in various gas atmospheres containing argon, water vapour and carbon dioxide. Rate equations have been derived for the ch emical decomposition of calcium carbonate with the formation of an int ermediate, activated calcium bicarbonate complex. The proposed rate eq uation for this mechanism takes into account surface poisoning either by inert gas-borne species or by CO2 and gives good agreement with res ults obtained both in the present study and in work by other authors.