(177c) Novel Approach to Remove Efal in Commercial Y-Zeolites and Its Catalytic Activity on Paraffin Cracking
AIChE Annual Meeting
2018
2018 AIChE Annual Meeting
Materials Engineering and Sciences Division
Synthesis and Application of Inorganic Materials: Synthesis
Monday, October 29, 2018 - 1:08pm to 1:27pm
The framework Si/Al atomic ratio of zeolites is an important parameter that exerts a strong influence on catalytic applications. Zeolite-Y is the prominent member of zeolite family cannot be directly synthesized with Si/Al ratios over ~2.5, which tenders low acidity and low hydrothermal stability.1 The low acidity of low-silica faujasites is usually explained in terms of a high density of Al substitutions in next-nearest neighboring positions.2 Customarily, post-synthetic modification such as hydrothermal dealumination was found to be most feasible way to increase the Si/Al ratio in the framework, thus enhancement of acidity and stability in zeolites.3-6 Most often, the âAlâ removed from zeolitic framework will fall into non-framework (extra framework). Due to EFAL species, the zeolite possesses low degree of crystallinity, which leads to complicated issues on catalytic applications. To avoid this, selective removal of extra framework aluminum (EFAL) is important to meet out various catalytic applications. In this study, a novel approach has been developed to remove only EFAL species from commercial Zeolite-USY. Various concentration of water glass was added to commercial zeolites and treated at various temperatures (RT to 100 °C) and duration (0-24 hrs) to remove EFAL from the zeolite materials. All the samples were well characterized by XRD, N2 adsorption-desorption measurements, ICP-AES, TEM and NMR. Cracking of Dodecane was studied as model catalytic cracking reaction to evaluate the catalytic properties of the EFAL removed samples and the results are compared with commercial zeolites.
References
- C. S. Symp. Ser., Washington, D.C, 1984, 248, 157.
- R. Sohn, S. J. Decanio, P. O. Fritz, J. H. Lunsford, J. Phys. Chem. 1986, 90, 4847.
- J. Kooyman, P. van der Waal, and H. van Bekkum, Zeolites 1997, 18, 50-53.
- Giudici, H.W. Kouwenhoven and R. Prins, Appl. Catal. A: Gen. 2000, 203, 101-110.
- S. Triantafillidis, A. G. Vlessidis and L. Nalbandian, N. P. Evmiridis, Micropor. Mesopor. Mater. 2001, 47, 369-388
- T.C. Vogt and B. M. Weckhuysen, Chem.Soc.Rev. 2015, 44, 7342-7370