Modeling And Experimental Studies On Absorption Of Carbon Dioxide By Higee Technology

This paper systematically reviewed previous researches on Rotating Packed Bed (RPB), including removal of carbon dioxide in RPB and theoretical and experimental researches about gas-liquid mass transfer in RPB. It is reported alkanolamines were used as absorbents when some researchers tried to remove carbon dioxide in RPB. While, Benfield solution, widely adopted in the prosess of ammonia synthesis, is never used to do that in RPB. Many papers were published on the studies of gas-liquid mass transfer in RPB. However, most of them were focused on the experiments and few on modeling and simulation. Therefore, this study is tried to make some breakthrough in these two aspects.In this study, experiments of removing carbon dioxide by Benfield solution in RPB under low pressure (the whole pressure is 0.4 MPa) were first carried out. The results demonstrated that, in the scope of experiments, the carbon dioxide removal efficiency increased with the increasement of liquid flow rate, rotating speed, temperature and concentration of the absorbent. Then, experiments under high pressure (the whole pressure is 1.2 MPa) were carried out. It was found the carbon dioxide removal efficiency was much higher compared with that under low pressure and its variation pattern against rotating speed was similar with that under low pressure.A mechanism model was presented to describe the gas-liquid mass transfer process with reactions in RPB operated at higher gravity level. The validity of the model is demonstrated by the agreement of the predicted results with the experimental data under various conditions (liquid flow rate, gas flow rate, ratating speed, temperature). Moreover, profile of gas-phase volumetric mass transfer coefficient along the radial direction of the packing was caltulated and it could reasonably illustrate end effect in RPB.Using the model in this study, simulation of removing carbon dioxide in flue gas was carried out under following different conditions, including high liquid flow rate, low liquid flow rate, increasing both inner and outer radius of packing, increasing outer radius of packing, decreasing outer radius of packing and packing containing two end effect zones. These simulation results could help us in operation and design of RPB.