Simultaneous Adsorption and Purification of Low-Concentration SO2 and H2S

The simultaneous adsorption and removal of low concentrations of SO₂ and H₂S using experimental and simulation methods were investigated in this paper. The adsorption breakthrough performance of the single-component SO₂ or H₂S was determined in the activated carbon fixed-bed test. Langmuir and extended Langmuir equations in the Aspen adsorption module were used to describe the adsorption equilibrium of the single and bi-component SO₂ and H₂S system, respectively. The effects of gas hourly space velocity (GHSV) and temperature on the dynamic adsorption process of the bi-component SO₂/H₂S system were investigated. The concentration distribution and adsorption capacity of SO₂/H₂S in the bed were simulated. The results showed that the simulation for the single-component breakthrough curves of SO₂ or H₂S agreed well with the experimental data. It indicated that the model and simulation yielded engineering acceptable accuracy. For the bi-component adsorption, the competitive adsorption effect was observed, with H₂S as the weakly adsorbed component and SO₂ as the strongly adsorbed component. The dynamic adsorption process showed the sequence of initial adsorption, breakthrough, replacement, and equilibrium. The breakthrough curves were characterized by the distinct hump (roll-up) for H₂S, resulting from the replacement effect. The influence of GHSV and the temperature on the dynamic adsorption process were investigated, revealing that the lower velocity and temperature enhanced the adsorption. This work might be used for the design and optimization of adsorption bed for the simultaneous removal of SO₂ and H₂S in Claus tail gas.