Hydrogen sulphide — air equilibria under claus furnace conditions

Equilibrium compositions of mixtures resulting from reactions between hydrogen sulphide and air at atmospheric pressure were calculated for temperatures and O2/H2S ratios ranging from 600 to 2000°K and 0.05 to 1.0, respectively. Forty‐four compounds containing nitrogen, hydrogen, oxygen and sulphur were assumed to be formed but only 25 had concentrations exceeding 0.1 ppm. These compounds should not, as in previous studies, be omitted from equilibrium calculations. Sulphur yields are shown to be increased by approximately 10% if O2/H2S ratios less than stoichiometric are used. Reasons for this and implications for Claus plant operation are provided.