Adsorption-Desorption Behavior of Hydrogen Sulfide Capture on a Modified Activated Carbon Surface.

Metal-based adsorbents with varying active phase loadings were synthesized to capture hydrogen sulfide (H2S) from a biogas mimic system. The adsorption-desorption cycles were implemented to ascertain the H2S captured. All prepared adsorbents were evaluated by nitrogen adsorption, Brunauer-Emmett-Teller surface area analysis, scanning electron microscopy-energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. From the results, modified adsorbents, dual chemical mixture (DCM) and a core-shell (CS) had the highest H2S adsorption performance with a range of 0.92-1.80 mg H2S/g. After several cycles of heat/N2 regeneration, the total H2S adsorption capacity of the DCM adsorbent decreased by 62.1%, whereas the CS adsorbent decreased by only 25%. Meanwhile, the proposed behavioral model for H2S adsorption-desorption was validated effectively using various analyses throughout the three cycles of adsorption-desorption samples. Moreover, as in this case, the ZnAc2/ZnO/CAC_OS adsorbents show outstanding performances with 30 cycles of adsorption-desorption compared to only 12 cycles of ZnAc2/ZnO/CAC_DCM. Thus, this research paper will provide fresh insights into adsorption-desorption behavior through the best adsorbents' development and the adsorbents' capability at the highest number of adsorption-desorption cycles.