Automated pH Monitoring and Control of TALSPEAK and Advanced TALSPEAK Processes

Area of Science:

• Chemical Engineering
• Analytical Chemistry
• Process Control

Background:

• Maintaining stable pH is critical for optimizing industrial processes, particularly solvent extraction.
• Solvent extraction in nuclear fuel reprocessing, like TALSPEAK and Advanced TALSPEAK, relies on pH-dependent metal ion separation.
• Precise pH control is challenging in these complex chemical environments.

Purpose of the Study:

• To develop and demonstrate an automated pH control system for solvent extraction processes.
• To integrate robust, real-time pH measurement with process control for enhanced efficiency.
• To validate the system's ability to maintain consistent pH during process perturbations.

Main Methods:

• Utilized Raman spectroscopy for accurate, near-instantaneous pH measurement of feed solutions.
• Developed a chemometric model to interpret Raman spectral data for pH determination.
• Integrated the Raman-based pH measurement with programmable logic controllers (PLCs) for automated control.
• Implemented a feedback loop where PLC adjustments corrected pH deviations.

Main Results:

• Achieved robust and rapid pH measurement using Raman spectroscopy and chemometrics.
• Demonstrated effective automated pH correction in response to acid/base perturbations.
• Successfully maintained a constant pH, enabling control over metal ion extraction.
• Validated the system's performance for real-time process control applications.

Conclusions:

• Automated pH control is feasible and effective for solvent extraction processes.
• Raman spectroscopy provides a powerful tool for real-time pH monitoring in industrial settings.
• The integrated system enhances process efficiency and control over critical separation steps.