Hydrogen sulfide removal by copper sulfate circulation method

Although copper sulfate (CuSO₄) as a valuable desulfurizer is commonly used in the laboratory, it is not applied in industry due to its high cost and lack of practical regeneration method. In this study, a method for regeneration of the absorption product copper sulfide (CuS) under mild conditions is put forward. In the presence of sodium chloride (NaCl), CuSO₄ could be regenerated smoothly in acid solution and be recycled for the absorption of hydrogen sulfide (H₂S). Specifically, under the conditions of 0.30 mol/L chloride ion (Cl^?), 1.8% acidity at 323 K, for 5.5 h, the regeneration efficiency will be higher than 99%. Moreover, extensive experimental studies showed that the addition of Cl^? would not observably influence the absorption efficiency of H₂S. These results reveal the potential for developing a novel, efficient and low-cost desulfurization technology.