Synthesis of high crystalline ZSM-5 zeolite and M(II)(Zn, Cu & Ni)-ZSM-5 and evaluation of their adsorptive desulfurization performance

摘要

High crystalline ZSM-5 was synthesized by hydrothermal method using localKaolin (Zonouz-EastAzarbaijan- Iran). The effect of several parameters such as time and template type on ZSM-5 crystallization and also calcination medium were studied. The as-synthesized ZSM-5 was characterized by XRD, FT-IR, SEM, TEM and BET surface area techniques. The ratio of Si:Al of synthesized ZSM-5 was 13 with a surface area of around 300 m2/g usingTPABr as template. The Zn(II)-ZSM-5,Cu(II)-ZSM-5 andNi(II)-ZSM- 5 sorbents were prepared through liquid phase ion exchange (LPIE) method at roomtemperature. Cation Exchange Capacity (CEC) for this zeolite was determined with ICP-AES technique. The ion exchanged ZSM-5 zeolites were used as adsorbents for removing of fuel organosulfurs in order to reduce air pollutants. The effect of each individual adsorbent is studied by using a model fuel (2000 ppm thiophene in toluene). The efficiency of the adsorbents was determined by Gas Chromatography analysis. Ð- complexation between thiophene ring and metal loaded in adsorbents is considered as removing mechanism. By increasing the cation amount in the adsorbents, the removing process improves. The Zn(II)-ZSM-5 adsorbent with themostmetal loading amount showed the best performance in thiophene removing (~64%).