ORP as slurry oxidation index and model modification in wet desulfurization system

Area of Science:

• Environmental Engineering
• Chemical Engineering
• Industrial Process Control

Background:

• Wet flue gas desulfurization (WFGD) systems often lack precise control over the oxidation process.
• Current pH control in WFGD is insufficient as it doesn't fully capture redox conditions.
• Instability in sulfite oxidation and gypsum quality are common issues in WFGD operations.

Purpose of the Study:

• To improve the semi-empirical formula for Oxidation-Reduction Potential (ORP) using actual desulfurization system data.
• To establish ORP as a viable control index for optimizing the oxidation process in WFGD.
• To enhance the stability and efficiency of WFGD operations.

Main Methods:

• Utilized operational data from an actual wet desulfurization system.
• Refined a laboratory-derived ORP semi-empirical formula.
• Validated the model by correcting ORP measurements using conventional power plant data.

Main Results:

• ORP in the actual system is primarily influenced by sulfite concentration and pH.
• Dissolved oxygen concentration shows minimal impact from minor operational changes.
• The developed model effectively corrects ORP measurements, demonstrating its practical applicability.

Conclusions:

• ORP serves as a crucial indicator for slurry oxidation degree in WFGD.
• Implementing ORP control can prevent over-oxidation and under-oxidation, leading to improved process stability.
• The findings provide theoretical support for integrating ORP as a key control parameter in WFGD systems.