Energy, economic and environmental (3E) analysis and multi-objective optimization of a spray-assisted low-temperature desalination system

Energetic, environmental and economic (3E) performances are major effective criteria that one needs to consider when designing and optimizing a desalination plant. In order to optimize all the three variables, it is important to determine an optimal system configuration and operation strategy at early design stages. Therefore, 3E analyses and multi-objective optimization of desalination systems are the areas of significant research interests. This paper specially conducts a 3E analysis and multi-objective optimization exercise of a spray-assisted low-temperature desalination technology through a judiciously developed mathematical model. Several optimization scenarios are studied to emphasize different performance variables. A multi-objective optimization is also performed to obtain the best trade-offs among these variables. Results revealed that the specific energy consumption highly conflicts with the initial investment, while the specific CO₂ emission and the initial investment present a positive correlation. The specific CO₂ emission can be minimized through the use of upward spray condensers, while the initial cost can be reduced by designing more compact spray evaporators and using cheaper materials.