【Frontiers in HaiChuan Chemical Technology】Dalian Institute of Chemical Physics’ technology for the full decomposition of hydrogen sulfide via electrocatalysis to produce hydrogen and sulfur has passed the evaluation for scientific and technological achievements

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On January 6, the \"off-site electrocatalytic complete decomposition of hydrogen sulfide for hydrogen and sulfur production\" technology developed by the team led by Academician Li Can from the Dalian Institute of Chemical Physics, Chinese Academy of Sciences (hereinafter referred to as the Dalian Institute of Chemical Physics), passed the evaluation of scientific and technological achievements organized by the China Petroleum and Chemical Industry Federation in Beijing. The experts on the evaluation committee unanimously agreed that this achievement is at the international leading level. It was unanimously agreed to approve the evaluation. It is recommended to expand the scale of the device and accelerate its promotion and application. Based on this technology, Li Can’s team, in collaboration with Shandong Sanwei Chemical Group Co., Ltd., Yulin Zhongke Clean Energy Innovation Institute, and Haoming Energy Technology (Dalian) Co., Ltd., completed the \"Industrial Demonstration Project for the Electrocatalytic Complete Decomposition of Hydrogen Sulfide to Produce Hydrogen and Sulfur Outside the Plant\". To a certain extent, this project addresses environmental pollution issues; it provides key green transformation solutions for industries such as natural gas, petrochemicals, and coal chemistry, and it also offers solid support for the development of resources with high hydrogen sulfide content as well as for the sustainable, low-carbon development of industry. The challenge of hydrogen sulfide elimination: Currently, the global energy system, which relies primarily on primary energy sources such as natural gas, oil, and coal, is facing environmental challenges posed by hydrogen sulfide emissions. As a highly toxic compound, hydrogen sulfide is easily oxidized to sulfur dioxide, resulting in acid rain that harms the ecological environment and human health. It is primarily associated with or produced as a by-product of natural gas extraction, the petroleum refining and chemical industry, and coal chemical processes. According to incomplete statistics, China processes approximately 8 billion cubic meters of hydrogen sulfide each year, while the global annual processing volume exceeds 70 billion cubic meters; the potential amount that needs to be processed is over 4 trillion cubic meters (data source: China Sulfuric Acid Industry Association, Hua Jing Industry Research Institute). Therefore, achieving the complete elimination and resource utilization of hydrogen sulfide has always been a long-standing challenge in industrial processes such as natural gas extraction, the petroleum refining and chemical industry, and coal chemistry. To overcome the aforementioned challenges, the team led by Academician Li Can has been working since 2003 on exploring the use of unconventional methods such as light and electricity to decompose hydrogen sulfide. After over a decade of research in the laboratory, the team successfully overcame the challenges associated with scaling up the process of hydrogen sulfide decomposition, and developed a technology for the complete decomposition of hydrogen sulfide into hydrogen and sulfur, which holds independent intellectual property rights in China. This technology decouples chemical reactions from charge transport in the reaction space, utilizing electron mediation to move electrode surface reactions away from the electrodes; thus, the oxidation of hydrogen sulfide to sulfur and the reduction of protons to produce hydrogen take place separately in reactors outside the electrodes. This design effectively solves the engineering problem of sulfur deposition on the electrode surface and its contamination of the battery separator, alleviates the impact of bubble adhesion dynamics on the hydrogen evolution reaction, enables the coupling of the electrochemical system with large-scale chemical plants and its scale-up, changes the reaction mode of traditional electrocatalytic systems, and possesses safety and reliability in terms of engineering principles. To date, 26 patents have been applied for in relation to this technology, of which 12 have been granted, resulting in a complete patent portfolio. Subsequently, the team led by Academician Li Can collaborated with enterprises to carry out industrial demonstration projects on the removal and resource utilization of hydrogen sulfide in the coal chemical industry. It mainly includes four aspects of technological innovation: off-site electrocatalytic complete decomposition of hydrogen sulfide for hydrogen and sulfur production technology ； Highly efficient and stable electrochemical cells and systems ； Sulfur dioxide oxidation-melting integrated reaction system with high conversion rate and efficient separation ； High-quality sulfur and high-purity hydrogen recovery technologies. This industrial demonstration project has established the first pilot-scale installation in China and abroad for the electrocatalytic complete decomposition of hydrogen sulfide to produce hydrogen and sulfur, with an annual capacity of 100,000 cubic meters. This installation uses hydrogen sulfide generated as a by-product from the 200,000-ton-per-year methanol production plant operated by Henan Energy Group’s Xinxiang Zhongxin Chemical Co., Ltd. It features a skid-mounted modular design and consists of three main units: one for the oxidation of hydrogen sulfide to produce sulfur, one for proton reduction to produce hydrogen, and one for electrochemical reactions. Operational data show that the unit has been running continuously for over 1,000 hours, achieving complete conversion of hydrogen sulfide (99.95% hydrogen sulfide in the exhaust gas, and hydrogen purity >99.999%). Original technology contributes to achieving the ‘dual carbon’ goals. According to technology novelty search reports and the current industrial landscape at home and abroad, no similar technologies have been reported previously; the ‘electrocatalytic full decomposition of hydrogen sulfide to produce hydrogen and sulfur’ technology is an original innovation in this field that possesses independent intellectual property rights. This technology provides a new approach for the complete elimination and resource utilization of hydrogen sulfide, enabling the effective treatment of pollution emissions such as hydrogen sulfide and thus protecting the ecological environment. It achieves dual benefits in terms of resource utilization through both hydrogen production and sulfur recovery, thereby expanding the options for producing clean and low-carbon hydrogen in industrial applications. At the same time, this technology also plays a positive role in promoting the development of China’s hydrogen energy industry and the construction of a low-carbon energy system, offering both environmental and economic benefits. According to predictions by the International Hydrogen Association, by 2030, China’s planned production capacity for green hydrogen will be around 1.8 million tons. If this technology is powered by wind and solar energy, it could be used to treat approximately 8 billion cubic meters of hydrogen sulfide in China each year. In doing so, around 730,000 tons of clean, low-carbon hydrogen could be recovered, which amounts to 40% of the planned production capacity for green hydrogen. This is of great significance for helping related industries achieve the \"dual carbon\" goals.