Recent advances in desulfurization technologies for clean biogas

초록

Biogas has attracted increasing attention as a renewable energy source. However, the presence of hydrogen sulfide (H2S) causes toxicity, corrosion, and catalyst deactivation, thereby necessitating efficient desulfurization strategies for its practical utilization. Although numerous desulfurization technologies have been reported, most previous reviews have relied on synthetic or simulated biogas; systematic comparisons under real biogas conditions remain scarce. Moreover, few reviews have jointly evaluated H2S removal performance, economic feasibility, and environmental impact. To address this gap, this systematic review focuses exclusively on the studies conducted under real biogas conditions. The desulfurization technologies are classified into physico-chemical methods, chemical oxidation/precipitation, and biological processes. The H2S removal performance, material characteristics, economic feasibility, and environmental impact of each technology were comparatively analyzed. The technologies relatively lately applied to H2S removal (e.g., ionic liquids, deep eutectic solvents, membrane separation, and electrochemical process) were also discussed as potential routes for overcoming the limitations of conventional technologies. The analysis indicates that adsorption processes show high H2S uptake capacities, particularly under low-concentration conditions. Chemical processes also achieve high removal efficiency, but they require intensive chemical consumption. Biological desulfurization is more economically and environmentally favorable over the long term, despite its higher initial investment. Finally, the need for additional research is emphasized in terms of applicability, long-term operational stability, sulfur recovery, and process scalability under real biogas conditions. These findings provide a practical basis for selecting and developing sustainable desulfurization strategies for real biogas purification. © 2026 Elsevier Ltd

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