The biogas chelated iron desulfurization technology is an efficient wet desulfurization technology for biogas developed by CSEE. This technology uses chelated iron as a catalyst and adopts redox to remove H₂S from biogas. Chelated iron desulfurization converts H₂S in biogas into elemental sulfur, H₂S removal efficiency is over 99%. The principle is that in an aqueous solution in an alkaline environment, H₂S is ionized into HS⁻, Fe³⁺(L) oxidizes HS⁻ into elemental sulfur, and at the same time, it is reduced to Fe²⁺(L) itself. During the regeneration process, Fe²⁺(L) is oxidized to Fe³⁺(L) by oxygen in the air to achieve regeneration. Technical features: High desulfurization efficiency, high desulfurization precision, low operating cost, non-toxic catalyst, stable operation, no salt blockage or sulfur blockage and no sewage discharge. Applicable to: Removal of H₂S from biogas and landfill gas.