Research on adsorptive desulfurization of H2S from natural gas over MnxOy-CoxOy supported on activated carbon

Abstract

MnxOy, CoxOy, and MnxOy-CoxOy supported on activated carbon (AC) adsorbents have been successfully prepared and characterized by specific surface area (BET), X-ray photoelectron spectroscopy, X-ray diffraction analysis, and Fourier-transform infrared spectroscopy. The results show that Mn is present in the form of Mn3+ and Mn4+, and Co is present in the form of Co2+ and Co3+. For all of the modified samples, the functional groups of the AC were well retained and the specific surface areas followed the order: AC>MnxOy-CoxOy/AC>Co3O4/AC>MnxOy/AC. For MnxOy-CoxOy/AC, Mn and Co mainly exist in the forms of MnO2, Co3O4, and Mn3Co2O8. MnxOy-CoxOy/AC was found to exhibit the best H2S desulfurization performance. At 20°C, the breakthrough time and saturated adsorption time were 115 min and 185 min, and the saturated sulfur capacity and desulfurization rate were 347.7 mg/g and 74.2%. The H2S removal capacities of the different adsorbents decreased in the order: MnxOy-CoxOy/AC>MnxOy/AC>CoxOy/AC>AC.