The role of membrane characteristics in improving vacuum membrane distillation efficiency: A lattice Boltzmann study

Abstract

With increasing water scarcity, membrane distillation technology has gained widespread attention as an innovative method for seawater desalination. However, existing studies often overlook the influence of membrane characteristics on mass transfer efficiency. This study, based on the lattice Boltzmann method, proposes a model for a novel Poly(tetraethynylpyrene) membrane material to reveal the influence of membrane characteristics on the performance of vacuum membrane distillation. The model considers factors such as porosity, tortuosity, membrane thickness, pore size, membrane surface wettability, temperature difference and vacuum pressure on the permeate flux. The results show that the permeate flux increases linearly with both the increase in porosity and the decrease in vacuum pressure, while it decreases exponentially with the tortuosity factor. The results show that the permeate flux increases linearly with the porosity and decreases exponentially with the tortuosity factor. There is an optimal membrane thickness (2 μm) beyond which the permeate flux decreases exponentially. In addition, the permeate flux increases exponentially with increasing temperature difference and pore size. Further analysis of the effect of membrane surface wettability shows that permeate flux increases with increasing hydrophobicity. Finally, the feed temperature and the tortuosity factor have the most significant effect on the permeate flux, followed by the membrane thickness, the pore size and finally the vacuum pressure, which has the least significant effect. The model can be further extended to study other configurations of membrane distillation technologies.