Studies On Mass Transfer Performance And Applications Of A Two-Stage Rotating Packed Bed With Foam Nickel Packing

Foam nickel packing makes up for foam ceramic’brittleness and foam plastic’s low temperature resistance and mechanical strength. It has high cost-efficiency and simple preparation process. Foam nickel packing has been widely used in chemical equipments and demonstrated good structural characteristics and excellent functions.In previous study, two-stage counter-current rotating packed bed (TSCC-RPB) showed high separation efficiency in continuous distillation. However, the TSCC-RPB has complex rotor structure with the combination of static and rotating rings. The high manufacture precision are demanded and resulted in high cost, which brings some obstacles to its industrial application. A novel two-stage rotating packed bed with foam nickel packing (TSFN-RPB) was developed in present work. In a TSFN-RPB, the rotor structure was simplified by using monolithic foam nickel packing. Firstly, the pressure drop characteristics and mass transfer performance of the TSFN-RPB were studied. The experimental results indicated that the pressure drop of the TSFN-RPB increased with increasing rotational speed and gas flowrate. The change of liquid flowrate has little influence on pressure drop of the TSFN-RPB. Under the same experimental conditions, the pressure drop in wet TSFN-RPB increased by20%～30%compared with that of the TSCC-RPB.The effective interfacial area (ae) and the gas phase overall volumetric mass transfer coefficient(KGae) of TSFN-RPB increased with increasing rotational speed, gas flowrate and liquid flowrate.In addition, the performance of the TSFN-RPB in distillation and absorption was investigated. For methanol-water system, the height equivalent of a theoretical plate(HETP) of the TSFN-RPB was24.1～40.8mm, and the separation efficiency increased by20%compared with that of TSCC-RPB. The absorption rate of CO2was closed to100%when the molar proportion of MDEA to PZ was0.5:0.5, the total molarity was3mol/L, the rotational speed was400r/min and the liquid-gas ratio was10L/m3, and the absorption rate of CO2in TSFN-RPB was increased by40%than that in one-stage RPB.