Modeling Study On Mass Transfer Enhancement In Membrane Absorption Process By Dispersed Particles

Membrane absorption technology is novel separate technology that combines membrane separation technology and traditional gas absorption technology. By adding the third phase particles into the liquid absorbent is the important method to enhance the traditional gas-liquid mass transfer process. In this work, the traditional of the enhancement of gas-liquid mass transfer model has been developed to describe the mass transfer behavior in membrane absorption process.For the steady-state membrane absorption process without the dispersed particles, a theoretical model, including the effect of membrane structure characteristics, liquid velocity and absorbent pH, has been developed based on the mass transfer differential equations and use the finite volume method to discretize the equations. The model calculated the mass transfer coefficient of the membrane absorption.For the steady-state membrane absorption process with the dispersed particles, an steady heterogeneous mass transfer model was proposed according to the partition of mass transfer region in which the shuttle effect mechanism and surface renewal theory were employed. The simulation uses CO2/H2O or C02/NaOH solutions as experimental system. The influence of particle concentration, stirrer speeds, particle sizes, flow rate, pH and viscosity of the absorbent were investigated. The results showed that with increase of particle concentration or decrease of the particle sizes, the enhancement factor started increased and then flattened. The enhancement factor reduced with increasing of the stirrer speeds. At the same particle concentration, the enhancement factor decreased when the flow rate of the absorbent was increased or pH was decreased. The enhancement factor reduced with the high viscosity of the absorbent. This model predictions agree well with the experimental data.