Effect of sequential dealumination and desilication on adsorptive desulfurization performance of NaY zeolite

The presence of sulfur compounds in transportation fuels have always been one of the most important issues discussed in scientific and industrial associations. In recent years, due to the adoption of global policies to address environmental problems, the study of efficient systems for desulfurization of fuels has attracted much attention. In this study, the adsorption desulfurization method was used to remove the sulfur compounds of thiophene and dibenzothiophene from fuel samples using NaY zeolite adsorbent. Mesoporosity was introduced in the NaY zeolite by the dealumination - desilication method with different concentrations of EDETA, HCL and NaOH solutions to increase the zeolite adsorption capacity. The synthesized samples were charectrized by BET, XRD and FE-SEM analysis. The BET results revealed that high mesopre surface area up to ۷۶ m۲/g was obtained for meso-NaY sample when the parent NaY zeolite was subjected to dealumination - desilication by EDETA - NaOH and it showed dealumination - desilication treatment by EDETA - NaOH was created more mesopores and lower destruction at zeolite structure, compared to dealumination - desilication by HCL - NaOH. According to experimental results in desulfurization performane, the zeolite adsorption capacity of samples increase in order of ۰.۱۱ M HCL - ۰.۴ M NaOH < NaY parent < ۰.۲ M EDETA - ۰.۸ M NaOH. This result showed that dealumination by HCL solution destructed the zeolite structure.

Keywords:

NaY , Dealumination - Desilication , Adsorption Desulfurization , Sulfur Compounds