Moisture recovery from gas-fired boiler exhaust using membrane module array

Many studies on the moisture recovery of flue gas by the membrane method use a single ceramic membrane tube to recover the simulated flue gas. In this paper, a membrane module array containing 46 ceramic membrane tubes was constructed to recover moisture and heat in real flue gas produced by a gas-fired boiler. The maximum recovered water flux was 15.77 kg/(m2·h), and the maximum heat flux was 14.83 MJ/(m2·h). Based on the experimental results, applying membrane module array in the thermal power plants could recover a considerable amount of water and heat. Recovering moisture could solve the water shortage problem of some thermal power plants, and decrease overall humidity in the lower atmosphere, which is conducive to the spread of pollutants in the lower atmosphere. Furthermore, the optimal boundary conditions of the experiments are discussed for guiding the actual production in the future. According to the results, the optimal operation temperatures of flue gas and cooling water are about 50 °C and 25 °C, respectively.