关键词:

水, ZSM-5型分子筛, 吸附, 分子模拟

Abstract:

The adsorption behavior of water on ZSM-5 was simulated by using the grand canonical ensemble Monte Carlo (GCEMC) method.The geometric structure and properties of ZSM-5 were first analysed by the Connolly surface methods and Solvent surface methods.Simulation results showed that Connolly free volume and the volume of water molecular inaccessible in zeolite gradually decreased with decreasing zeolite ratio n_Si/n_Al.ZSM-5 zeolite was strongly hydrophobic under low pressure conditions, and its adsorption capacity would increase with increasing pressure.Desorption curves had a certain lag, and this proved the existence of capillary rally phenomenon.The adsorption capacity of ZSM-5 zeolite exchanged by K⁺, Na⁺, Ca²⁺ had a significant change, and increased with increasing aperture size.The adsorption capacity of zeolite increased with Si atoms replaced by Ti atoms in zeolite matrix, while it would decrease with increasing number of Al atoms replaced by Ti atoms.At the same adsorption capacity, the absorption heat reduced with increasing n_Si/n_Al ratio or aperture size.

Key words:

水, ZSM-5型分子筛, 吸附, 分子模拟