A novel zero-liquid discharge desalination system based on the humidification-dehumidification process: A preliminary...

Area of Science:

• Environmental Engineering
• Chemical Engineering
• Materials Science

Background:

• Brine, a byproduct of desalination, poses environmental risks.
• Current zero-liquid discharge (ZLD) systems face challenges with high energy intensity and costs.
• Crystallizers in ZLD systems are a key area for cost and energy reduction.

Purpose of the Study:

• To introduce a novel crystallization method for ZLD systems based on humidification-dehumidification (HDH).
• To evaluate the feasibility, energy consumption, and cost-effectiveness of the proposed HDH crystallization process.
• To address the limitations of existing ZLD crystallizers.

Main Methods:

• Development and testing of a novel crystallization method using humidification-dehumidification (HDH).
• Experimental setup utilizing heated air (40 °C) as the heat source for brine concentration and salt crystallization.
• Thermo-economic analysis of the complete ZLD system.

Main Results:

• Successful brine concentration and salt crystallization were achieved using the HDH method.
• The proposed system demonstrated significantly lower energy consumption (700-900 kJ/kg brine thermal, 5-11 kJ/kg brine electrical).
• A 56% reduction in energy consumption and a 58% reduction in initial plant cost compared to conventional evaporative crystallizers were observed.

Conclusions:

• The novel HDH crystallization method is a feasible and effective approach for ZLD systems.
• This method offers substantial reductions in energy consumption and plant costs.
• The system presents a promising, cost-effective, and energy-efficient solution for managing desalination brine and reducing environmental impact.