Enhancing performance of ceramic membranes for recovering water and heat from flue gas

Transport membrane condenser can efficiently recover water and heat from wet flue gas. Ceramic membrane is the heat and mass transfer medium in the process. However, the relationship between membrane property and the recovery performance is only partially reported based on current research state. This work focuses on the effects of permeability, material, and ceramic particle size of membrane on the water and heat recovery. Membranes were prepared from three different sizes of coal fly ash and an alumina powder. Water and heat recovery performances of the membranes are experimentally compared. Results indicate that increasing membrane permeability improves water and heat recovery because the resistance of heat and mass transfer is reduced. The alumina membrane performs 3-10% more water recovery than the coal fly ash-based membrane while thermal conductivity of the alumina membrane was 11.5 times that of the coal fly ash-based membrane. Increasing ceramic particle size shows two opposite effects on the water and heat recovery, promotion because of the permeability rising, and undermine because of the thermal conductivity reduction. Low-cost membranes with high perme-ability and high thermal conductivity are recommended in transport membrane con-denser application.

Automated summary

Transport membrane condenser efficiently recovers water and heat from wet flue gas using ceramic membrane as the medium for heat and mass transfer. This study investigates the impact of membrane permeability, material, and ceramic particle size on water and heat recovery. Experimental comparison of membranes prepared from coal fly ash and alumina powder of different sizes reveals that increasing membrane permeability improves recovery, with alumina membrane outperforming coal fly ash-based membrane in water recovery by 3-10% despite having a thermal conductivity 11.5 times higher. Increasing ceramic particle size has conflicting effects on recovery, promoting it through permeability increase but impairing it due to reduced thermal conductivity. Therefore, low-cost membranes with high permeability and thermal conductivity are recommended for transport membrane condenser application.