Kinetics of absorption of hydrogen sulfide into aqueous ferric sulfate solutions

Absorption experiments of H2S into aqueous Fe2(SO4)3 solutions, concerned with a unique process capable of regenerating by biological oxidation the reactant from the products, were performed at 20–40°C in an agitated vessel with a flat interface. The absorbents were aqueous solutions of Fe2(SO4)3 with and without the addition of K2SO4, KOH or H2SO4 of various concentrations, which was added to change the ionic strength or pH of the solutions. The experimental results revealed that the species which reacts with H2S is FeOH2+. While comparing the observed absorption rates with the theoretical predictions, it was found that the reaction is irreversible and first order with respect to H2S and FeOH2+. The reaction rate constants were measured and correlated.