Heat exchange and water recovery experiments of flue gas with using nanoporous ceramic membranes

The application of a 20 nm pore-sized porous ceramic membrane for condensation heat transfer in artificial flue gas was presented in this work, and the phenomenon of capillary condensation was investigated. A parametric study was conducted to illustrate the behavior of heat transfer and water recovery by varying the parameters of feed gas, cooling water and vacuum in water side. Results indicate that the amount of recovered water and heat increase with the growth of the feed gas flow rate, feed gas temperature, relative humidity, but decrease with the increase of cooling water inlet temperature. Within a certain range of vacuum (above −5 kPa), changing the cooling water flux has little influence on water recovery. The water recovery rate of the module can be up to above 80% and the heat recovery efficiency can be up to above 40% as well, using the low temperature cooling water. These values can both reach 90% in proper conditions. In addition, when the cooling water temperature is higher than the feed gas dew point, the water recovery rate can still reach above 20% with the help of capillary condensation.