A Three-Dimensional Macrocosmic Mass Transfer Model for Gas Absorption Enhanced by Adsorptive Solid Particles

A three-dimensional heterogeneous macrocosmic mass transfer model was proposed. The effect of some parameters such as solid adsorptive capacity and diameter distribution on gas absorption was studied in detail. From the results, the adsorption capacity of particles played an important role in gas absorption. With an increase of particle capacity, the adsorption driving force increases greatly, resulting in higher enhancement factors. Different change trend of the enhancement factor with particle diameter was found for different particle adsorption capacity. For high adsorptive capacity particles, the enhancement factor decreases with an increase of particle diameter monotonically, while an initial increase and a subsequent drop of enhancement factor was observed for the particles with small adsorptive capacity. When the particle capacity is high, the effect of size distribution should be taken into account, otherwise a large error may occur. The turbulent degree of liquid could change the residence time of the particle at gas-liquid interface, interfacial coverage and liquid mass transfer rate and consequently affect the mass transfer. The influence of stirring speed on mass transfer should be an overall result of the above aspects. The model was validated by experiments and the prediction valves agreed well with the experimental data.