Liquid Redox process is that converts hydrogen sulfide (H₂S) into elemental sulfur in the liquid phase based on the chelated iron solutions, with simultaneous sulfur recovery. During the oxidation of H₂S to elemental sulfur, ferric ions (Fe³⁺) in the catalyst are reduced to ferrous ions (Fe²⁺). The ferrous ions are then regenerated back to ferric ions (Fe³⁺) by air, enabling continuous cyclic reuse. Elemental sulfur produced in the reaction is separated and recovered using a plate-and-frame filter press.
H₂S in the gas is absorbed into the chelated iron solution and oxidized to elemental sulfur by ferric ions:
H₂S+2Fe3+→S↓+2Fe2++2H+
Ferrous ions are oxidized back to ferric ions by air (oxygen), realizing catalyst regeneration:
4Fe2++O₂+2H₂O→4Fe3++4OH−
2H₂S+O₂→2S↓+2H₂O
The produced sulfur particles are large and with clear solid-liquid separation, resulting in high separation efficiency and low solution loss.
The regeneration system off-gas contains only air, with no H2S or other pollutant emissions.
The working sulfur capacity can reach above 0.3%, while that of conventional catalyst is typically less than 0.1%.
No waste liquid or other by-products are generated during operation except elemental sulfur.
High-quality sulfur foam with high sulfur loading, no light/empty foam issues.
H₂S removal of natural gas
H₂S removal of associated gas
Acid gas tail gas treatment and sulfur recovery
Refinery gas H₂S removal
Biogas H₂S removal
Syngas H₂S removal
We provide one-stop after-sales service, including on-site installation guidance, operation training, remote guidance for troubleshooting, on-site support when necessary, and guarantee for catalyst supply.
It adopts the Liquid Redox method. Chelated iron act as catalysts: H₂S is oxidized to elemental sulfur (S) in alkaline absorption solution.
It is widely compatible with natural gas, biogas, petroleum gas, syngas and acid tail gas.
The outlet H₂S can be stably controlled below 10ppm, and even below 5mg/Nm³ with high-quality processes, meeting ultra-low emission requirements.
Yes, and the transformation is convenient. There is no need to rebuild the tower; only the spray, regeneration and sulfur recovery systems need to be optimized. The transformation cycle is short, the investment is low, and the shutdown time is minimized.
Absorption/regeneration towers can use carbon steel + anti-corrosion lining or 304/316 stainless steel; pipelines, pumps and tanks need internal anti-corrosion for carbon steel to avoid local corrosion.
The main operating costs include catalyst consumption (core cost), alkali consumption, power consumption (solution circulating pump, regeneration fan), and waste water treatment.
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