Power generation: analysis of the mnumber (alkalinity) in cooling water

Significance of Topic

Cooling water alkalinity control is fundamental to maintain protective oxide layers on metal piping in power plants, preventing corrosion and scale formation. Optimizing water chemistry ensures efficient heat transfer in condensers, reduces downtime, and lowers maintenance costs.

Objectives and Overview of the Article

• Describe the online measurement of m-alkalinity in cooling water via potentiometric titration.
• Demonstrate integration of Metrohm Process Analytics instruments with power plant control systems for real-time monitoring.
• Highlight how faster response times improve process control and efficiency.

Methodology and Instrumentation

• Titration to pH 4.5 with 0.1 mol/L HCl using a pH electrode to quantify total alkalinity (m-alkalinity).
• Endpoint detection based on pH/mV changes correlated with titrant volume.
• Instruments:
  
  • 2026 Titrolyzer – single-parameter potentiometric titration analyzer.
  • 2035 Process Analyzer – potentiometric titration and ion-selective measurements.
  • 2060 TI Process Analyzer – modular online wet chemistry platform supporting titration, photometry, and standard addition.

Main Results and Discussion

• Rapid determination of m-alkalinity in under 30 minutes provides near real-time data.
• Measurement range of 0–110 mmol/L (as CaCO₃) covers typical cooling water conditions.
• Online data feed to the Distributed Control System (DCS) enables immediate corrective actions.

Benefits and Practical Application of the Method

• Continuous monitoring prevents corrosion and scaling, extending equipment lifespan.
• Automated sampling and diagnostics reduce manual intervention and enhance safety.
• Integration with DCS lowers maintenance costs and increases plant uptime.

Future Trends and Opportunities

• Integration of advanced sensors and machine-learning algorithms for predictive maintenance.
• Expansion of multi-parameter analyzers for comprehensive water quality monitoring.
• IoT connectivity for remote monitoring and centralized data analytics across multiple plants.

Conclusion

Online potentiometric titration of m-alkalinity using Metrohm Process Analytics instruments delivers fast, accurate, and automated alkalinity monitoring in power plant cooling water. This approach enhances process control, mitigates corrosion and scaling risks, and reduces operational costs.

References

• Application Note AN-PAN-1003: Amine (rich and lean) and free & total CO2