Maxwell-Stefan理论模拟NaA沸石膜分离一氯甲烷中微量水的渗透特性

通过热浸渍晶种法制备了高质量的NaA沸石膜，并将其应用于蒸汽渗透脱除一氯甲烷中的微量水. 实验结果表明，NaA膜对该体系显示了优异的分离性能，水对一氯甲烷的分离系数高达74831，产品中的水含量从0.2582%(w)降低到0.005%(w). 将基于Maxwell-Stenfan理论和Langmuir理想吸附理论推导的吸附-扩散模型用于模拟水渗透流速与渗透侧真空度和进料温度的关系，预测趋势与实验值吻合很好，且拟合得到的参数与文献报道较接近，表明水蒸汽在NaA沸石膜中的传递为表面扩散机制，水蒸汽的吸附对渗透速率的贡献很大. 水蒸汽的吸附热为-34.15 kJ/mol.

Permeation Property of Trace Water in the Chloromethanes through NaA Zeolite Membrane Simulated by Maxwell-Stefan Theory

High quality NaA zeolite membrane was prepared secondary hydrothermal synthesis using hot dip-coating seeding and studied for the removal of trace water from chloromethanes by vapor permeation. The NaA zeolite membrane showed an excellent separation selectivity of water over chloromethanes as high as 74831, the water content of product decreased from 0.2582%(ω) to 0.005%(ω). The observed water permeation dependencies of pressure and temperature were simulated by Maxwell-Stefan approach. There was good agreement between the simulated and observed results. It reveals that water vapor permeation is governed by surface diffusion, and the adsorption isotherm of water is Langmuir type, the adsorption water plays an important role in the water permeation flux. Furthermore the calculated adsorption enthalpy of water was -34.15 kJ/mol.