镧改性LaZSM-5 分子筛固定床动态吸附分离甲酚 性能研究

Lanthanum-modified LaZSM-5 zeolite was synthesized using lanthanum nitrate and HZSM-5 as raw materials via ion exchange method. XRF and nitrogen adsorption-desorption were used to characterize zeolites. Both static adsorption and fixed-bed adsorption process were employed to investigate the separation performance of LaZSM-5 for m-cresol and p-cresol. Effects of adsorbent type, cresol feed concentration, and packing height on the fixed-bed breakthrough curves were systematically investigated. The breakthrough curves were analyzed and predicted using the Thomas model, and an industrial mixed cresol sample was used to investigate the practical separation performance of LaZSM-5. The results demonstrated that LaZSM-5 exhibited an enhanced adsorption selectivity for p-cresol of 6. 27, triple more than that of HZSM-5. Lower feed concentrations and greater packing heights significantly improved the separation efficiency. LaZSM-5 achieved adsorption capacities of 38. 1 mg·g^-1for p-cresol and 8. 9 mg·g^-1for m-cresol in the separation of industrial mixed cresol, still maintaining efficient separation performance. This study is of great value for the application of ZSM-5 zeolite in the adsorption and separation of cresols.