MOLECULAR SIMULATION OF n-HEXANE ADSORPTION ON HZSM-5 ZEOLITES WITH DIFFERENT Si/Al RATIO

Abstract

Abstract: The adsorption behavior of n-hexane on HZSM-5 zeolites with different Si/Al ratios has been simulated by Grand Cannonical Monte Carlo method. By simulating the adsorption of n-hexane molecules on HZSM-5 zeolites with different Si-Al ratios at 298 K and 423 K, some parameters such as the adsorption isotherm, adsorption energy density, adsorption potential energy, radial distribution function and other related parameters were obtained and analyzed, and the effect of Si/Al ratio on the adsorption behavior of n-hexane was also analyzed. The results show that the adsorption between n-hexane and HZSM-5 zeolite accords with the Langmuir-Freundlich adsorption model. When the Si/Al ratio is high, n-hexane molecules adsorbs preferentially on B acid sites of T3 and T9 in the inter channels of HZM-5 zeolites and the interaction between n-hexane molecules is more obvious than other B acid sites. With the decrease of Si/Al ratio, the saturated adsorption capacity of n-hexane was increased, the adsorption ratio of n-hexane molecules adsorbed in the straight channel was increased, and the interaction between hexane molecules was weaken.

Key words: Monte Carlo, molecular dynamics, n-hexane, HZSM-5 zeolite, Langmuir-Freundlich adsorption model

References

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