Mass transfer performance of water recovery from flue gas of lignite boiler by composite membrane

摘要

Membrane technology is a potential way for water recovery from the flue gas of the lignite boiler. Consider the influences of the micro-scale configuration of the membrane and the operating parameters, the physical process was modeled based on the Stefan Maxwell theory, as well as the composite membrane resistance model for numerical simulation. The mass transfer process of flue gas in coating, transition layer and support layer of the composite membrane was analyzed respectively. The theoretical results were both verified by experiments and numerical simulations. The influences of different materials, pressure difference, porosity and transition layer thickness on the water vapor permeation flux were revealed. The results show that the high Henry coefficient and the high selectivity of water vapor have great advantages in the application, and the increase of pressure, porosity and thickness of the transition layer are all beneficial to increase the water vapor flux. Based on the theoretical model, the multi attribute decision making method was employed to provide suggestions for membrane material selection of gas water recycling in the experimental researches as well as in the engineering applications.