| On the basis of rotating packed bed (RPB), a noval Higee device named rotor-stator reactor (RSR) was invented in 2006. It consists mainly of a series of concentric rotor-rings and stator-rings alternately configured in the radial direction. In the RSR, high speed rotation of the rotor creates a centrifugal field and shear force which cause the liquid stream to split into small liquid droplets, thin liquid films and violent turbulence of the gas and liquid streams, resulting in a remarkable intensification of both micromixing and mass transfer processes. Therefore, the RSR has broad application prospects in chemical processes controlled by mass transfer.In this dissertation, the liquid flow and gas-liquid mass transfer process in the RSR were studied, and NH3-water-in-oil (W/O) microemulsion system and W/O emulsion were employed to synthesize Ce0.5Zr0.5O2 and MgCl2 respectively in the RSR with the aim of controlling size and size distribution of the particles. The main research contents are as follows:1. Visual study on liquid flow in the RSR was carried out with a high-speed camera, and the effects of various operating conditions such as the number of rotor-ring/stator-ring layers, the rotation speed and the liquid volumetric flow rate on the average diameter as well as the average velocity of liquid droplets and the average angle of velocity vector were investigated. The results showed that the average diameter of water and microemulsion droplets were in the range of 311-1045 μm and 271-775 um, respectively; the average velocity of water and microemulsion droplets were in the range of 1.73-8.86 m·s-1 and 2.08-7.34 m·s-1, respectively. Correlations were established to predict the average diameter and the average velocity of the liquid droplets, and the predicted values were found to be in agreement with the experimental values with deviations within 15%.2. The effective gas-liquid specific interfacial area (ac) in an RSR was investigated by chemical absorption of CO2 into NaOH solution, and the effects of operating conditions such as the rotation speed, the liquid volumetric flow rate and the gas volumetric flow rate on ae were examined. The results showed that ae in the RSR were in the range of 126.6-211.6 m2·m-3. Correlations were established to predict ae, and the predicted values were found to be in agreement with the experimental values with deviations within 5%.3. The overall volumetric mass transfer coefficient (Kya) in an RSR was incestigated by absorption of NH3 into water, and the effects of operating conditions such as the rotation speed, the liuqid volumetric flow rate and the gas volumetric flow rate on Kya were inveatigated. The results showed that Kya in the RSR was in the range of 47.3-97.5 mol·m-3·s-1.A correlation was established to predict Kya, and the predicted values were found to be in agreement with the experimental values with deviations within 10%. A comparison of Kya between the RSR and the RPB showed that the Kya in the RSR was 13% higher than that in the RPB due to the better mass transfer intensification,4. The NH3-water-in-oil (W/O) microemulsion system was employed to study the mass transfer process in an RSR. The effects of water content on the density and viscosity of the microemulsion and the Henry’s constant of the NH3-microemulsion system as well as the influences of operating conditions such as the water content of the microemulsion, the rotation speed, the liquid volumetric flow rate and the gas volumetric flow rate on Kya were investigated. The results showed that Kya in the RSR was in the range of 19.5-73.0 mol·m-3·s-1. A comparison of Kya between the RSR and packed tower showed that the Kya in the RSR was 65% higher than that in the packed tower due to the better mass transfer intensification,5. Nano-Ce0.5Zr0.5O2 particles were prepared by absorption of NH3 into W/O microemulsion in an RSR. The effects of different operating conditions including the reaction temperature, the rotation speed and the gas-liquid volumetric ratio were investigated. Nano-Ce0.5Zr0.5O2 with an average diameter of 5 nm, a specific surface area of 216 m2·g-1 and a size distribution of 4-8 nm was obtained under the optimum operating conditions of reaction temperature of 303 K, rotation speed of 800 rpm and gas-liquid volumetric flow ratio of 2.7. The as-prepared nano-Ce0.5Zr0.5O2 was loaded with Au to prepare nano-Au/Ce0.5Zr0.5O2 catalyst which was subsequently used for CO oxidation test. CO conversion rate reached 100% at room temperature, indicating high catalytic activity of the nano-Au/Ce0.5Zr0.5O2 catalyst.6. An emulsion system was employed to prepare spherical MgCl2 supporter in an RSR. The effects of different operating conditions including rotation speed, emulsifying time and the length of tube were investigated. MgCl2 particles with an average diameter of 28-138 μm and a span of 1.0 was obtained under the optimum operating conditions of rotation speed of 800 rpm, emulsifying time of 40 min and tube length of 1.0 m. The as-prepared MgCl2 supporter was loaded with Ti to obtain the catalyst which showed high catalytic activity in the liquid-phase bulk polymerization and can meet the requirements for the preparation of spherical polypropylene. |
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