Experimental Study on Water Recovery from Flue Gas Using Macroporous Ceramic Membrane

Area of Science:

• Material Science
• Chemical Engineering
• Environmental Engineering

Background:

• Flue gas emissions contain valuable resources like water vapor and waste heat.
• Efficient recovery systems are crucial for industrial sustainability and energy conservation.
• Ceramic membranes offer potential for selective separation and heat exchange applications.

Purpose of the Study:

• To investigate the performance of a ceramic membrane tube for simultaneous moisture and waste heat recovery from flue gas.
• To analyze the impact of operational parameters on recovery efficiency.
• To determine optimal conditions for maximizing water and heat recovery.

Main Methods:

• Experimental setup using a 1 μm pore size ceramic membrane tube (800 mm length, 8/12 mm inner/outer diameter, 27.2% porosity).
• Flue gas flowed on the shell side, with counter-current water coolant flow through the membrane.
• Systematic variation of flue gas flow rate, flue gas temperature, water coolant flux, and water coolant temperature.

Main Results:

• Increased flue gas flow rate and temperature led to higher recycled water amounts and recovered heat.
• Elevated water coolant temperature reduced recycled water, recovered heat, and heat recovery rate, with a sharp drop above 30 °C.
• Maximum recovery achieved: 2.93 kg/(m²·h) recycled water, 3.63 kW/m² recovered heat, and a total heat transfer coefficient of 224.3 W/(m²·K).

Conclusions:

• Ceramic membrane technology is viable for recovering moisture and waste heat from flue gas.
• Optimizing flue gas conditions and maintaining lower coolant temperatures are key for efficient recovery.
• The system shows significant potential for industrial waste stream valorization and energy savings.