热致相分离聚偏氟乙烯膜接触器法高压吸收CO_2过程及数学模拟

Physical Absorption of CO_2 Using Polyvinylidene Fluoride Membrane Contactor at High Pressure and Mathematical Simulation

研究了膜接触器法高压吸收混合气中CO2的过程,考察水作为吸收剂时,操作压力、气体和吸收剂流量对聚偏氟乙烯(PVDF)中空纤维膜脱除CO2效果的影响.通过物理传质模型得出气相、膜相和液相的传质方程式,构建了二维数学模型,并结合边界层条件和多物理场耦合分析软件(COMSOL MULTIPHYSICS)对膜接触器法高压物理吸收CO2的过程进行了模拟预测.结果表明,吸收过程中膜的润湿情况显著影响CO2传质效果;在数学模型中引入润湿率,可以较准确预测CO2的物理吸收效果.

The removal of CO2 from natural gas using polyvinylidene fluoride （PVDF） hollow fiber membrane contactor was studied at high pressure. The distilled water was used as absorbent. The effects of operating pressure, inlet gas flow rate and liquid flow rate on removal efficiency of CO2 were investigated. Based on the physical mass transfer process, the mass transfer equation of gas phase, membrane phase and liquid phase were established. The outlet CO2 content could be predicted using Muhiphysics （COMSOL） combined with 2-D mathematical model and corresponding boundary conditions. The results showed that the removal efficien- cy of CO2 was affected significantly by the partial wetting of membrane. The predicted results were in good agreement with the experimental data if the wetting ratio of membrane was considered in the mathematical model.