中空纤维膜接触器精馏过程传质性能的研究

The mass transfer performance of hollow fiber membrane contactors in the distillation of ethanol-water mixtures

以乙醇-水体系的精馏分离为研究对象,选用不同装填分率的中空纤维膜组件,研究了中空纤维膜接触器的气液传质性能。结果表明:不同装填分率的中空纤维膜接触器,随着装填分率的减小,壳程膜丝分布更加均匀、传质阻力减小、传质性能提高;乙醇-水体系的精馏传质过程为液膜控制,可通过控制液相传质来改善总传质效果;当装填分率一定时,随着气相速度的增加,总传质系数增大、传质性能增强,且其实际值与理论值存在差异。

Hollow fiber membrane modules with different packing densities were used in the separation of ethanol-water mixtures by distillation to investigate the gas-liquid mass transfer performance of the hollow fiber membrane contactors. The results show that when the packing density decreases,the membrane distribution is more uniform on the shell-side which,as a result,decreases the transfer resistance and enhances the mass transfer performance.The ethanol-water distillation process is liquid controlled and the overall mass transfer effects could be improved by controlling the liquid phase. When the packing density is constant,the overall mass transfer coefficient is larger,and the mass transfer performance is enhanced,with increasing vapor velocity,and the experimental mass transfer coefficient differs from the theoretical one.