Objective  The aim is to improve the situation of poor stability, low sulfur capacity and easy blockage of equipment in the traditional liquid phase oxidative-reduction desulfurizer for the Lo-cat liquid phase oxidative-redution desulfurization process suitable for medium and small-scale sulfur-containing wellhead gas desulfurization, and to further develop a greener and more efficient wet oxidation desulfurizer system.

Method A green and efficient copper-based wet oxidative-reduction desulfurization agent was prepared by adding copper chloride and chelating agent with a mixture of N, N-Dimethylformamide (DMF) and water as solvent. The structure and thermal stability of the desulfurization agent were determined, and desulfurization experiments were carried out in order to test the effects of different kinds of chelating agents, the ratio of copper ions and chelating agent, temperature, water content, and gas flow rate of H₂S on the desulfurization performance. At the same time, the change rule of redox potential and pH during the absorption and regeneration process and the repeated desulfurization performance of desulfurization agents were investigated.

Result The developed desulfurizer could work stably below 60 ℃, and the optimal desulfurization temperature was 40 ℃. In the desulfurization solution composed of 30 mL DMF+10 mL water, the desulfurizer composed of 2 g CuCl₂ and 2 g amine chelating agent had a relatively high desulfurization effect, and the sulfur capacity was up to 14.83 g/L.

Conclusion  The developed desulfurizer has a high sulfur capacity while efficiently absorbing H₂S, which can provide a reference for the natural gas desulfurization process.