Seawater Reverse Osmosis (SWRO) Desalination: Energy consumption in plants, advanced low-energy technologies, and future developments for improving energy efficiency

High-energy consumption is a critical issue associated with seawater reverse osmosis (SWRO) desalination, although the SWRO has been regarded as one of the most energy-efficient processes for seawater desalination. This means that SWRO involves a larger amount of fossil fuel and other energy sources for water production, which imposes a negative impact on the environment such as greenhouse gas emission. Therefore, the high-energy consumption of SWRO should be addressed to minimize environmental impacts and to allow for sustainable exploitation of seawater. However, the recent trend of energy consumption in SWRO seems to have  reached  a saturation point, which is still higher than theoretical minimum energy. To find new and innovative strategies for lowering current energy consumption, a comprehensive understanding of energy use in SWRO plants from theoretical analysis to actual energy consumption in real SWRO plants is required. This book can provide readers with information about the current state of energy consumption in actual SWRO plants, the fundamental understanding of energy use of SWRO plants from theoretical point of view, and advanced technologies and processes that could be applied for future energy reduction. In addition, this book will offer a detailed methodology for analyzing energy issues in seawater desalination. Through this book,  readers will obtain an insight into how to deal with and analyze the energy issues in SWRO desalination.

Chapter 1 Reverse osmosis
Introduction
Definition and Osmotic Pressure
Principle of RO

Chapter 2 SWRO desalination plants
Overall Process
SWRO Intake: Open water intakes, Subsurface intakes
Pre-Treatment: Dissolved air flotation, Dual media filtration, Membrane-based pretreatment, Cartridge filter
RO System Equipment: High-pressure pump, Energy-recovery device
RO Membranes
RO Configurations: RO pass configuration, SWRO system configuration, BWRO system configuration
Post-Treatment: Stabilization and corrosion control, pH adjustment, Alkalinity adjustment, Hardness (CaCO3) adjustment, Disinfection, Aeration and degasification
Discharge: Conventional discharge strategy, Discharge to injection wells, Discharge to offshore galleries and trenches, Zero liquid discharge (ZLD), Dilution of concentrate using forward osmosis process

Chapter 3 Energy consumption in SWRO operation
Membrane Transport Mechanism in a Small-Scale System: Solution–diffusion theory, Permeate resistance, Concentration polarization, RO fouling
Membrane Transport Mechanism in Module-Scale Operation
Energy Consumption Model in the RO Process

Chapter 4 Recent trends in the SEC of SWRO
SWRO Plants Worldwide: Data collection, Data processing, Trends in datasets
Increasing Large-Scale SWRO Applications
Using ERDs with High Energy Efficiency
Increasing Product Water Quantity
Improving Product Water Quality
Applying Multiple Pretreatment Methods for Harmful Algal Blooms
Performing Retrofitting and Expansion
Utilizing Renewable Energy

Chapter 5 Factors affecting the SEC of SWRO plants
Specific Energy Consumption of Pre- and Post-Treatment
Feed Conditions: Feed salinity, Feed temperature, Overall feed conditions
Equipment Efficiency: ERD efficiency, Pump efficiency
Target Conditions: Permeate quality, Permeate quantity
Summary and Future Directions

Chapter 6 Advanced technologies for a low-energy SWRO process
Theoretical Energy Calculation of the SWRO Process: Exergy analysis for theoretical minimum energy, Analysis of future directions for low-energy SWRO, Maximum available margin for low-energy SWRO
Minimizing Irreversibility in a High-Pressure Pump: Multistage RO, Semi-batch RO, Batch RO, Hybrid batch RO, Energy comparison of minimizing irreversibility in HPP
Reducing the Osmotic Pressure of Seawater: Split partial single pass, FO and reverse osmosis (RO) hybrid process, Draw solution-assisted RO, Energy comparison of reducing the osmotic pressure of seawater
Osmotic Energy Recovery in Concentrate Streams: Pressure retarded osmosis, Reverse electrodialysis, Osmotic energy recovery in a concentrate stream
Improvement of RO Membranes: Introduction of novel building blocks, RO membrane surface modification, Biomimetic RO membranes, Inorganic RO membranes, Mixed matrix RO membranes

Chapter 7 Concluding remarks and epilogue

Acknowledgments

References

Index