Study Of Porosity On The Mass Transfer Performance In Microporous Membrane Gas Absorption

Membrane absorbers are a novel technology for replacing conventional scrubbers for flue gas cleaning. Owing to their high specific surface area, membrane absorbers provide higher volumetric mass transfer rates than convention scrubbers. Numerous former approximate empirical models that described mass transfer process in the literature all neglected the influence of the surface porosity of the membranes, and the models have put forward to adapt the definite module in given systems in their experiments. When two kinds of hollow fiber membrane (HFM), which have different surface porosity, were used in the experiments under various operation conditions, it was found that the actual mass transfer area is not equal to the total area of the HFM wall. Several plate membranes that have different surface porosity were applied in the experiment and the result also proved the effect of the diversity of the mass transfer area. A generic theoretical model for overall mass transfer coefficient calculation has been developed, which incorporates these effects and describes the influence of the surface porosity. Thereby, the results corrected expressions for the real mass transfer capacity of the membrane and the actual value of the mass transfer coefficient can be calculated.