Modeling of H2S Absorption by Iron Chelate Aqueous Solution in a Turbulent Contact Absorber

In this article, desulphurization from the gas streams containing hydrogen sulfide by aqueous iron chelate solutions in a turbulent contact absorber is mathematically and experimentally investigated. The desulphurization is accomplished by a precipitation reaction that occurs when sulfide and ferric ions are brought into contact with each other. Absorption experiments (Mobile Bed Absorber) contained low density hollow plastic balls as packing, which were entangled between two perforated plates. The experiments were conducted in different operating conditions (Gas flow rate: 22-28 lit/min, Iron Chelate flow rate: 0.2-0.5 lit/min, Hydrogen Sulfide Concentration: 3000-4000 ppm and Static Packing Height: 13 and 23 cm). A mathematical model was used to predict the removal efficiency of H2S absorption into a ferric chelate solution in the Mobile bed absorber. From mass balances in the absorber, a set of ordinary differential equations, which relate the species concentrations in the gas and liquid phases, along the axial direction in the scrubber were formulated. These relationships were numerically solved to obtain the performance of the absorber. The validity of the model was examined by comparing the results of the model with our experimental data. The predicted results of the model are in good agreement with the experimental data obtained in different operating conditions. The effects of the liquid (aqueous catalyst solution) flow rate, static height of the packing, and packing size on the absorption efficiency were also studied.