Event-driven enabled regression aided multi-loop control for SEC minimisation in SWRO desalination considering...

Area of Science:

• Chemical Engineering
• Environmental Engineering
• Process Control

Background:

• Seawater reverse osmosis (SWRO) is crucial for desalination but energy-intensive.
• Maintaining consistent permeate flow during feed salinity fluctuations poses operational challenges and impacts energy efficiency.
• Specific energy consumption (SEC) is a key metric for evaluating desalination process efficiency.

Purpose of the Study:

• To develop an energy-minimized operation strategy for SWRO desalination.
• To identify optimal manipulating variables for controlling permeate flow under varying feed salinity.
• To propose an advanced control strategy that surpasses traditional methods in energy reduction and control smoothness.

Main Methods:

• Simultaneous manipulation of feed pressure and reject valve opening.
• Specific Energy Consumption (SEC) analysis under dynamic feed salinity conditions.
• Development of a multi-loop control strategy using event-driven programming and a regression-based predictive model.
• Validation using a previously established dynamic model of the SWRO process.

Main Results:

• The proposed control strategy significantly reduces energy requirements for SWRO.
• A reduction in feed pressure by approximately 300 kPa was achieved during feed salinity variations.
• The new methodology demonstrates smoother control transitions compared to traditional PID control.
• Energy-minimized operation of the reverse osmosis (RO) process is enabled.

Conclusions:

• The proposed event-driven, predictive control strategy offers superior performance over conventional PID control for SWRO.
• This approach effectively minimizes energy consumption in SWRO desalination.
• The strategy provides a viable solution for efficient water production in the face of changing environmental conditions.