Liquid Redox for h2s treating sulfur recovery technology uses a chelated iron solution to convert H₂S elemental sulfur.
Single-Tower Oxidation-Regeneration and Dual-Tower Oxidation-Regeneration, allowing optimal selection based on specific project requirements. It is widely applied across natural gas, petrochemical, and biogas upgrading industries.
Our H₂S Treatment Solution List
Liquid Redox
Single-Tower Oxidation Regeneration Process
Dual-Tower Oxidation Regeneration Process
Catalysis and Adsorption
Skid-mounted System
Chelated Iron Solutions
Catalysis and Adsorption Solutions
Chemical
DEFINITION
What is Liquid Redox?
Liquid Redox is a chemical oxidation-based process used for hydrogen sulfide (H₂S) treatment in gas streams, wastewater, and industrial emissions. It removes hydrogen sulfide by converting it into elemental sulfur through a continuous liquid-phase reaction, making it an efficient and regenerable H₂S treatment technology for industrial applications.
Unlike one-time-use chemical hydrogen sulfide scavengers, the liquid redox for H₂S treating operates in a regenerative system, allowing the oxidizing solution to be continuously regenerated and reused. This makes it a cost-effective and environmentally friendly solution for large-scale hydrogen sulfide removal and sulfur recovery.
PRINCIPLE
Working Principle of Liquid Redox
The Liquid Redox process treats H₂S by converting it 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.
Reaction Mechanism & Process Flow
1. Absorption & Oxidation
H₂S in the gas is absorbed into the chelated iron solution and oxidized to elemental sulfur by ferric ions:
H₂S+2Fe3+→S↓+2Fe2++2H+
2. Regeneration of Catalyst
Ferrous ions are oxidized back to ferric ions by air (oxygen), realizing catalyst regeneration:
4Fe2++O₂+2H₂O→4Fe3++4OH−
3. Overall Reaction
2H₂S+O₂→2S↓+2H₂O
FEATURES
Technical Features of Liquid Redox
Easy Separation:
The produced sulfur particles are large and with clear solid-liquid separation, resulting in high separation efficiency and low solution loss.
No Exhaust Emissions:
The regeneration system off-gas contains only air, with no H2S or other pollutant emissions.
High Sulfur Capacity:
The working sulfur capacity can reach above 0.3%, while that of conventional catalyst is typically less than 0.1%.
Zero Liquid Discharge:
No waste liquid or other by-products are generated during operation except elemental sulfur.
Stable Foam Performance:
High-quality sulfur foam with high sulfur loading, no light/empty foam issues.
APPLICATIONS
Applications of Liquid Redox
H₂S removal of natural gas
H₂S removal of associated gas
Acid gas tail gas treatment and sulfur recovery
Refinery gas H₂S removal
Removal of H2S from biogas
Syngas H₂S removal
FAQs of Liquid Redox
Q
What after-sales support can you provide?
A
WINVO, as a professional H2S services company, 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.
Q
What is the core principle?
A
It adopts the Liquid Redox method. Chelated iron act as catalysts: H₂S is oxidized to elemental sulfur (S) in alkaline absorption solution.
Q
Which gases can be treated by liquid redox?
A
It is widely compatible with natural gas, biogas, petroleum gas, syngas and acid tail gas.
Q
What is the H₂S removal efficiency?
A
The outlet H₂S can be stably controlled below 10ppm, and even below 5mg/Nm³ with high-quality processes, meeting ultra-low emission requirements.
Can the existing HPF/ADA unit be transformed into Liquid Redox?
A
Yes, and the retrofit is straightforward 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.
Q
What material is suitable for the equipment?
A
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.
What are the main operating costs?
A
The main operating costs include catalyst consumption (core cost), alkali consumption, power consumption (solution circulating pump, regeneration fan), and waste water treatment.
Q
What is the difference between liquid redox and scavengers?
A
Liquid redox systems continuously regenerate a liquid solution to convert H₂S into elemental sulfur, making them suitable for large, continuous gas streams. In contrast, scavengers are typically chemical consumables that permanently react with H₂S and are not regenerated. Liquid redox is more economical for high-volume applications, while scavengers are better suited for smaller or intermittent gas flows.
