Heat and water recovery from gaseous stream using a flat-sheet ceramic membrane as a transport membrane condenser

Abstract

Ceramic-membrane technology has been employed to recover waste heat and vapor from moist gases. In addition to the hydrophilicity, pore size, and porosity of separation materials, a membrane condenser can achieve a high recovery rate. In this study, a transport membrane condenser (TMC) was successfully constructed using a flat-sheet ceramic membrane (FCM) with a large pore size of 45.54 μm. The membrane characteristics, including the mean pore size, pore size distribution, and porosity, were investigated to determine their recovery mechanism. Their water and heat fluxes, recovery rates, and thermal resistance were compared under several experimental conditions. The inlet conditions significantly affect the TMC recovery performance. Higher recovery fluxes were obtained at lower water temperatures, higher gas temperatures, and higher gas flow rates. However, when the Reynolds number of water increased, the heat flux increased rapidly, and the recovered water decreased slightly. The highest TMC water recovery rate was 84.1%. In addition, to further analyze the separation mechanisms, a two-dimensional model was developed using ANSYS Fluent code. The simulation results were compared with the experimental data to verify the accuracy of the numerical method. The comparison results showed a high degree of consistency.

Keywords

• Flat-sheet ceramic membrane
• Heat recovery
• Water recovery
• Transport membrane condenser
• Computational fluid dynamics