Study On The Mass Transfer Enhancement Of CO₂Absorption Into Zeolite/water Slurry

The enhancement of mass transfer of lower solubility gas is an importantproject for chemical process research, especially introducing a third dispersedphase to improve gas-liquid mass transfer drew wide attention in recent years.The intensifications of four different SiO₂/Al₂O₃ratio zeolites to CO₂absorption under different conditions were experimentally investigated. And aone dimensional （1-D） and a three dimensional （3-D） heterogeneous masstransfer models were proposed to depict the intensification of mass transfer inCO₂absorption.The experiments were carried out in a thermostatic stirred tank, the effectof SiO₂/Al₂O₃ratios, initial pressure, CO₂partial pressure, solid loading onCO₂absorption were investigated, respectively. The results indicated that theenhancement factor increased with the increase of SiO₂/Al₂O₃ratios, butreduced with the increase of initial pressure, CO₂partial pressure and stirringspeed. When solid loading increased, the enhancement factor increasedsharply at first and then gradually leveled off to a constant value. Furthermore,the effect of ultrasound to enhancement factor was also investigated, theintensification of mass transfer by zeolite was improved when the slurry wasultrasounded.A1-D heterogeneous model was proposed based on the classical“shuttle” mechanism, the calculated average enhancement factor by thismodel under different conditions agreed well with the experimental results.Furthermore, a3-D heterogeneous model was proposed, and the effect ofdifferent factors on the enhancement factor from multi-dimensional wasstudied. The average and instantaneous enhancement factors were calculatedby the3-D heterogeneous model. Compared to the1-D model, the average andinstantaneous enhancement factors calculated by3-D model were moreprecise which proved that the3-D model was more reasonable.