Template-free Synthesis Of ZSM-5/Y Composite Zeolite And Desulfurization Performance

ZSM-5, Y and ZSM-5/Y composite molecular sieves were synthesized through template-free hydrothermal synthesis method. The preparation conditions for ZSM-5/Y composite molecular sieve were investigated and analyzed. The traditional synthesis methods were to make use of the structure directing agent. Despite the excellent template effect of cations, It caused many adverse problems such as high product coast, organic species contained in channel system due to incomplete decomposition and environment problems from thermal de composition of organic species. Cu-ZSM-5/Y and Fe-ZSM-5/Y composite molecular sieves were prepared by liquid phase ion exchange method with Cu2+ and Fe3+ cations. ZSM-5/Y based sorbent was developed for adsorptive desulfurization?ADS? of the thiophene/cyclohexane model oil as feedstock with static desulfurization.ZSM-5, Y and ZSM-5/Y composite molecular sieves were prepared through template-free hydrothermal synthesis method. On the basis of characterization and analysis, the different factors that influence the crystallization of ZSM-5 molecular sieve was the crystallization temperature, crystallization time, and SiO₂/Al₂O₃; the different factors that influence the crystallization of Y molecular sieve was the crystallization time, and SiO₂/Al₂O₃; the different factors that influence the crystallization of ZSM-5/Y composite molecular sieve was the crystallization time, Y directing agent dose and SiO₂/Al₂O₃. The experimental results indicated that:?1? The better ZSM-5 molecular sieve was synthesized at 175 ?C for 72 h after stirring at high speed;?2? The better Y molecular sieve was synthesized under the conditions which was crystallized at 100 ?C for 24 h;?3? The better ZSM-5/Y composite molecular sieves was synthesized under the conditions which was crystallized at 100?C for 24 h, the Y directing agent amount was 20 % on SiO₂. Besides, Y molecular sieve was synthesized by microwave radiation under microwave temperature 100 ?C, power 300 W and microwave time 4 h.Cu-ZSM-5/Y and Fe-ZSM-5/Y composite molecular sieves were prepared by liquid phase ion exchange method with Cu2+ and Fe3+ cations. ZSM-5/Y based sorbent was developed for adsorptive desulfurization?ADS? of the thiophene/cyclohexane model oil as feedstock with static desulfurization. On the basis of experimental evaluation, the different factors that influence the adsorptive desulfurization of ZSM-5/Y composite molecular sieve included adsorption time, adsorption temperature, adsorbent dosage, adsorbent activation temperature and the kind of metal ions. The experimental results indicate:?1? The desulfurization of metal ions prepared by liquid-phase ion-exchange is better than H-ZSM-5/Y composite molecular sieve;?2? The desulfurization rate is highest under the condition of adsorption time 60 min, adsorption temperature for ambient temperature and stirring;?3? Several performance desulfurizer to remove thiophene sulfur compounds experiment were prepared: Cu-ZSM-5/Y > Fe-ZSM-5/Y > H-ZSM-5/Y > Cu-ZSM-5 > Cu-Y.