A replacement for the Claus process? ? ? Complete decomposition of hydrogen sulfide at room temperature and atmospheric pressure achieved by Dahuahua

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　　According to Sinochem News, recently, the team led by Academician Li Can from the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, developed an electrocatalytic technique that enables the complete decomposition of hydrogen sulfide into hydrogen and sulfur at room temperature and normal pressure. This technique holds the potential to replace the current Claus process used in industry, allowing for the elimination and utilization of hydrogen sulfide in natural gas extraction, the petroleum refining industry, and coal chemical processes. It could also serve as a new approach for producing green hydrogen at low cost. 　　It is reported that the team led by Academician Li Can began researching the use of unconventional techniques for the decomposition of hydrogen sulfide in 2003. They explored methods such as photocatalysis, electrocatalysis, and photoelectrocatalysis to produce hydrogen and sulfur from hydrogen sulfide, thereby verifying the feasibility of the photoelectrocatalytic approach in principle. 　　In this study, the research team addressed the issue of scaling up hydrogen sulfide decomposition processes. By using electron-mediated drive, they decoupled the chemical reactions from the charge exchange reactions at the electrode surface. Moreover, by employing modern chemical reactors, they transferred the oxidation reaction (sulfur formation) and the reduction reaction (hydrogen release) away from the electrodes, thereby developing off-electrode electrocatalytic technology. By connecting a kettle-type reactor and a suspended-bed/fixed-bed reactor outside the electrochemical cell, they achieved the decomposition of hydrogen sulfide to produce sulfur as well as the hydrogen evolution reaction, while using the electrochemical cell for the regeneration of the electron mediator pair. To date, the research team has completed pilot-scale technical verification and long-term operation tests at a rate of 100 liters of hydrogen sulfide per day; the conversion efficiency of hydrogen sulfide exceeds 99.9999%, emissions of sulfur-containing pollutants are below one part in a million, and the purity of hydrogen reaches over 99.999%. 　　The relevant research findings were published in the American Chemical Society’s journal in the field of environmental science, titled Environmental Science & Technology. The reviewers believe that this off-site electrocatalytic technology represents a significant advancement in the field of complete decomposition of hydrogen sulfide to produce hydrogen and sulfur, offering a promising and innovative new approach that can compete with current Claus processes. 　　To date, 17 patents have been applied for for this technology, of which 7 have been granted, resulting in an original series of technologies with independent intellectual property rights. Furthermore, this technology holds considerable application prospects, with several companies planning to put it into practical use. 　　According to incomplete statistics, China’s annual hydrogen sulfide production is around 8 billion cubic meters, while the global figure is about 70 billion cubic meters per year. The removal and resource utilization of hydrogen sulfide is a challenge that industries such as natural gas extraction, the petroleum refining sector, and coal chemical processing have faced for a long time. The current high-temperature oxidative Claus process eliminates sulfur compounds by oxidizing them into sulfur and water, but large amounts of sulfur-containing compounds are released in the exhaust gases, requiring further secondary treatment; moreover, even after multiple Claus processes, sulfur-containing pollutants cannot be completely removed. Furthermore, the Claus process only yields sulfur, with hydrogen being converted into water, resulting in a loss of resources.