Biogas purification is essential for mitigating corrosion and environmental risks associated with acidic impurity gases. In this study, yeast–alginate hydrogel composite biosorbents prepared by Ca²⁺ gelation followed by Fe³⁺ secondary crosslinking were investigated for selective acidic-gas removal in a fixed-bed column system. Response surface methodology (RSM) was employed to optimize key operating parameters governing the biosorption process. The Fe³⁺-crosslinked yeast–alginate composites exhibited markedly enhanced removal of H2S and CO2 compared with non-Fe³⁺ controls, while CH4 loss remained consistently below 5%, indicating preferential removal of acidic gases over methane. Structural and physicochemical characterizations confirmed the formation of a stable mesoporous network with effective Fe³⁺ incorporation, and biological assays demonstrated preserved yeast viability after adsorption. Overall, these results highlight the potential of Fe³⁺-crosslinked yeast–alginate composite biosorbents as a selective and sustainable material for biogas purification and provide a foundation for further evaluation under continuous-flow conditions.
Wang et al. (Fri,) studied this question.