Chinese scientists use off-site electrocatalytic technology to achieve complete decomposition of hydrogen sulfide

Recently, the team led by Academician Li Can from the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences successfully developed an off-site electrocatalytic technology that can fully deComposehydrogen sulfide to produce hydrogen and sulfur at room temperature and pressure. This technology is expected to replace the current Claus technology in the industry, achieve the elimination and resource utilization of hydrogen sulfide in natural gas extraction, oil refining and coal chemical processes, and become a new path for low-cost green hydrogen production. The relevant results were published in the international environmental journal Environmental Science and Technology.

Hydrogen sulfide is a highly toxic compound and an important resource. It is usually produced as a byproduct of natural gas extraction, oil refining and coal chemical processes. According to incomplete statistics, China’s annual hydrogen sulfide production is about 8 billion cubic meters, and the global annual production is about 70 billion cubic meters. The elimination and resource utilization of hydrogen sulfide is a long-term issue faced by industries such as natural gas extraction, oil refining, and coal chemical industry. The current high-temperature oxidation Claus process eliminates hydrogen sulfide by oxidizing it into sulfur and water, but a large amount of sulfur-containing compounds are discharged in the tail gas and require further secondary treatment. In addition, the Claus process only obtains sulfur, and the conversion of hydrogen into water also causes resource loss.

As early as 2003, Li Can's team began to work on the research of hydrogen sulfide decomposition reaction using unconventional technologies. They have successively used photocatalysis, electrocatalysis, photoelectrocatalysis and other technologies to explore the decomposition of hydrogen sulfide to produce hydrogen and sulfur, and verified the feasibility of the photoelectrocatalytic technology route in principle.

In this work, the R&D team decoupled the chemical reaction from the charge exchange reaction on the electrode surface through electron-mediated driving, and used modern chemical reactors to transfer the oxidation reaction (sulfur generation) and reduction reaction (hydrogen release process) away from the electrode, thus developing an off-site electrocatalytic technology. Currently, the team has completed the technical verification and long-term operation experiment of a small-scale laboratory test of 100 liters of hydrogen sulfide per day.

This technology has applied for 17 patents and 7 authorizations, and has considerable application prospects. Currently, many companies in the fields of natural gas extraction, oil refining, and coal chemical industry are planning the transformation and implementation of this technology.