疏水性中空纤维膜组件操作过程模拟

Process Simulation for Module Operation of Hydrophobic Hollow Fiber Membrane

采用疏水性中空纤维膜组件和去离子水分离混合气中CO2,研究了气液流速、混合气CO2浓度和操作温度以及膜形态等因素对总传质系数的影响。通过传质阻力层方程和质量微分方程的关联,建立了新型数学模型,模拟了各种条件下的传质过程。结果表明,流体力学状态的改变能够加强传质,但加强程度有限;提高气相CO2浓度能够提高总传质系数;具有高孔隙率的膜组件拥有高传质系数;提高操作温度能够促进扩散,提高传质系数,在较高温度下,存在膜孔湿润的现象。模型能够较好地模拟膜接触器—物理吸收过程,模型值能够较准确地反映疏水性中空纤维模组件传质过程。

Separation of CO2 from the gas mixture was performed by a module with the hydrophobic PP （polypropy lene） microporous membrane and using the deion water. Effects of gas and liquid flowrates, CO2 concentration and operation temperatures as well as membrane configuration on overall mass transfer coefficient were investigated. A mathematical model was presented by correlating the resistance in series and the mass differential equation. Mass transfer was simulated under the various operation conditions. Results show that the change of hydrodynamics in the module can enhance mass transfer finitely. Overall mass transfer coefficient can be increased with the increase of CO2 concentration. Membrane modules with high porosity possess a high mass transfer coefficient. Elevation of operation temperatures can accelerate the diffusion and enhance the mass transfer. Partial micropores may be wetted at higher operation temperatures. The operation process of hydrophobic hollow fiber membrane module can be better simulated by the model. The modeling results are in good agreement with experiments.