Abstract
Adsorptive removal of nitrogen containing compounds (NCCs) from high temperature coal tar over Y zeolites has received more attention for its mild operating conditions. In order to eliminate the diffusion limitation caused by zeolites micropores, a series of nanosheet hierarchical Y zeolites have been synthesized through a three–stage temperature method without the addition of template in this work. The results indicate that the particle size, pore structure and acid properties of synthesized samples can be easily tuned by controlling the H2O/SiO2 ratio of precursor gel, which was confirmed by a series of analysis. The adsorbent with the H2O/SiO2 ratio at 20.1 consists of best relative crystallinity of primary zeolite, the highest BET surface of 850 m2·g−1, the highest total acidity of 0.43 mmol·g−1 and the largest amount Lewis acid sites (LAS) of 928.2 μmol·g−1, which made it a superior candidate for denitrogenation adsorbents. In addition, the relationship between the structure of adsorbents and their denitrogenation performance was evaluated by batch adsorption experiments in model fuels. The results demonstrate that the ZY20.1 exhibited the highest adsorption capacity of 17.09 mg N·g−1 adsorbent for quinoline (QUI) and 21.51 mg N·g−1 adsorbent for indole (IND), respectively, which is roughly twice that of the conventional NaY. ZY20.1 also has an excellent adsorption selectivity for NCCs and can effectively resist the effect of competitive components. Furthermore, the adsorption performance in real fraction and its good regeneration performance of ZY20.1 confirm its potential commercial application. In this study, a kind of structurally controllable nanosheet Y zeolite with enhanced adsorptive denitrogenation was prepared by a green and environmental method, which will provide useful guidance for the development of efficient denitrogenation material.
Published Version
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