| A rotating packed bed (RPB, also called Higee device) is a novelequipment for the intensification of mass transfer and multiphase mixing.It consists mainly of a packed rotor. Due to the high-speed rotation of therotor, liquid is submitted to the action of a strong centrifugal force,usually dozens to thousands times larger than the gravitationalacceleration on the earth, when flowing through the packed rotor.Because of the continuous collision between liquid and packing, theturbulence and surface renewal rate of the liquid is enhanced, leading to asignificant increase of the mass transfer and micromixing efficiency inthe RPB. In view of the unique properties of RPB in mass transfer andmixing, it has been widely used in chemical processes such as absorption,desulfurization, nanomaterials preparation, water treatment, distillationand so on.Simultaneous absorption of multicomponent gases is an emergingabsorption process in recent years. The production processes and cost canbe reduced by using the simultaneous absorption processes, resulting in the increase of comprehensive benefits of enterprises. This dissertationinvestigated the mechanism and rule of the simultaneous absorption ofCO2and NH3into water in an RPB. The effects of different operationconditions on the absorption process of CO2and NH3into water in theRPB were studied. In order to develop a feasible methodology for theutilization of NH3, CO2and certain salt solution, the preparation ofinorganic micro/nano-materials by simultaneous absorption of NH3andCO2in salt solution in an RPB was also studied. The main researchcontents are as follows:1. Investigated the mechanism and characteristics during thesimultaneous absorption of CO2and NH3into water, NaCl solution,CaCl2solution, and MgCl2solution in an RPB. The precise designequation and part design equation of an RPB were deduced by adoptingthe practical boundary conditions. A reaction mass-transfer model wasestablished and used for the prediction of the mass-transfer coefficient(KGa) of the simultaneous absorption of CO2and NH3into water in anRPB. By the comparison of the predicted value and experimental value,we found that the deviation is within10%, and the model exhibits goodprediction ability for KGa value in the RPB.2. Investigated the effects of different operating conditions,including NH3/CO2molar ratio, rotation speed, liquid volumetric flowrate, gas volumetric flow rate and temperature, on the mass-transfer coefficient of NH3and CO2during the simultaneous or separateabsorption of CO2and NH3into water in an RPB. And the optimaloperating conditions of a rotation speed of1000rpm, a liquid volumetricflow rate of200L h-1, a gas volumetric flow rate of2400L h-1, aNH3/CO2molar ratio of2and a temperature of293K were obtained inthis simultaneous absorption process. A NH3absorption rate of99.2%, aNH3mass-transfer coefficient of1.8×10-4mol Pa-1 m-3s-1, a CO2absorption rate of50.6%and a CO2mass-transfer coefficient of2.6×10-5mol Pa-1 m-3s-1can be achieved under the optimal operating conditions.3. Investigated the effects of different operating conditions,including rotation speed, liquid volumetric flow rate, gas volumetric flowrate, NH3/CO2molar ratio and temperature, on the mass-transfercoefficient of NH3and CO2during the simultaneous or separateabsorption of CO2and NH3into saturated NaCl solution in an RPB. Andthe optimal operating conditions of a rotation speed of800rpm, a liquidvolumetric flow rate of25L h-1, a gas volumetric flow rate of1100L h-1,a NH3/CO2molar ratio of2and a temperature of293K were obtained inthis simultaneous absorption process. A NH3absorption rate of99.04%, aNH3mass-transfer coefficient of7.4×10-5mol Pa-1 m-3s-1, a CO2absorption rate of42.2%, a CO2mass-transfer coefficient of8.1×10-6mol Pa-1 m-3s-1can be achieved under the optimal operating conditions.4. Investigated the preparation of nano-CaCO3by simultaneous absorption of NH3and CO2into CaCl2solution in an RPB, andinvestigated the effects of different operating conditions, includingreaction temperature, rotation speed, liquid volumetric flow rate, gasvolumetric flow rate and initial concentration of CaCl2solution, on thecharacteristic of nano-CaCO3. And the optimal operating conditions of arotation speed of1000rpm, a liquid volumetric flow rate of200L h-1, agas volumetric flow rate of2400L h-1, a NH3/CO2molar ratio of2, atemperature of293K, a NH3concentration of14%and a CO2concentration of7%were obtained in this process. The nano-CaCO3witha mean size of50nm, a particle size distribution of10-80nm wasprepared under the optimal operating conditions. The process provides apromising pathway for the utilization of CaCl2wastewater and NH3-andCO2-containing exhausts as resources.5. Investigated the preparation of basic magnesium carbonate (BMC)by simultaneous absorption of NH3and CO2into MgCl2solution in anRPB, and investigated the effects of different operating conditions,including rotation speed, liquid volumetric flow rate, gas volumetric flowrate, reaction temperature and initial concentration of MgCl2solution, onthe shape, structure and size of BMC. And the optimal operatingconditions of a rotation speed of1100rpm, a liquid volumetric flow rateof300L h-1, a gas volumetric flow rate of1000L h-1, a NH3/CO2molarratio of2, a temperature of343K, a NH3concentration of6%and a CO2 concentration of12%were obtained in this process. The BMC with amean size of5.3μm, a nano-slice microstructure of25nm, a particle sizedistribution of2.8-7μm was prepared under the optimal operatingconditions. This process shows potentials for the utilization of MgCl2wastewater and NH3-and CO2-containing exhausts as resources.
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