Electro-absorption as a high-efficiency strategy for continuous H2S removal from gas streams
The electrooxidation of absorbed contaminants within the electrolyte of an electrochemical cell (electro-absorption) offers a promising avenue for the advanced treatment of gaseous pollutants, yet their application to non-volatile organic compounds remains underexplored. This study evaluates the con...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universidad de Castilla-La Mancha |
| Repositorio: | RUIdeRA. Repositorio Institucional de la UCLM |
| OAI Identifier: | oai:ruidera.uclm.es:10578/45414 |
| Acceso en línea: | https://doi.org/10.1016/j.jece.2025.119740 https://www.sciencedirect.com/science/article/pii/S2213343725044367 https://hdl.handle.net/10578/45414 |
| Access Level: | acceso abierto |
| Palabra clave: | Electro-absorption Gas treatment Hydrogen sulphide Jet mixer Packed column |
| Sumario: | The electrooxidation of absorbed contaminants within the electrolyte of an electrochemical cell (electro-absorption) offers a promising avenue for the advanced treatment of gaseous pollutants, yet their application to non-volatile organic compounds remains underexplored. This study evaluates the continuous electrochemical oxidation of hydrogen sulphide (H2S) using two absorption configurations—a packed column and a jet mixer—and two phosphate-based absorbents: sodium phosphate (Na3PO4) and sodium hydrogen phosphate (Na2HPO4), which produce different operation pH ranges (phosphate buffers). While both configurations demonstrated comparable H2S absorption capacities, Na3PO4 significantly outperformed Na2HPO4, achieving complete H2S removal and facilitating its full oxidation to sulphate. The jet mixer configuration notably enhanced the electrochemical conversion of absorbed H2S, attributed to increased turbulence and improved gas-liquid interaction. Under optimised conditions (Na3PO4, jet mixer, 10 mA cm?²), 100 % of the supplied H2S (2 mg min?¹) was continuously eliminated, with sulphate identified as the dominant oxidation product. The conversion efficiency increased with current density, although coulombic efficiency declined, peaking at 65 % under low current conditions. These findings underscore the critical role of electrolyte composition and reactor hydrodynamics in maximising pollutant removal and product selectivity. The superior performance of Na3PO4 is likely linked to its alkaline pH, which favours oxidation kinetics. Overall, the electro-absorption system, particularly the jet mixer coupled with Na3PO4, emerges as a robust, scalable, and environmentally sustainable technology for gas stream decontamination, with potential for valorising H2S into commercially viable sulphate compounds. |
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