(667f) Hydrogen Sulfide Removal from Biogas on Nitrogen-Doped Hierarchical Carbons

The increasing concern for sustainability impels people to seek more renewable energy. As one type of renewable energy from anaerobic digestion process, biogas or anaerobic digestor gas, has gained significant attention. However, the presence of hydrogen sulfide (H₂S) in biogas limits its application due to the odor, corrosivity and sulfur-toxicity. Meanwhile, nitrogen-doped porous carbon (NC) materials have been explored in gas processing due to their merits in terms of high surface area, large pore volume, high thermal and chemical stability, etc. This work studied the H₂S sorption performance from biogas on NC materials deriving from carbonization of ZIF-8. Herein, the H₂S sorption performance on a series of NCs was investigated. The N content and textural properties of adsorbents were varied by different carbonization conditions resulting in different H₂S sorption performance. It was shown that NC carbonized at 800 ℃ exhibited the highest H₂S sorption capacity, while NC carbonized at 950 ℃ achieved the highest N efficiency. Detailed characterization results (XPS, XRD, FT-IR, and TGA/DTA) were used for understanding the sorption mechanism. Additionally, the H₂S sorption capacity was not impacted by the increase of the inlet CO₂ concentration which implies that NC sorbents are promising for removing H₂S from biogas.