Reza Yazdanpanah, Eshagh Moradiyan, Rouein Halladj* and Sima Askari Pages 1 - 12 ( 12 )
Aim and Objective: The research focuses on recent progress in the production of light olefins. Hence, the common catalyst of the reaction (SAPO-34) deactivates quickly because of coke formation, we reorganized the mechanism combining SAPO-34 with a natural zeolite in order to delay the deactivation time.
Materials and Methods: The synthesis of nanocomposite catalyst was conducted hydrothermally using experimental design. Firstly, Clinoptilolite was modified using nitric acid in order to achieve nano scaled material. Then, the initial gel of the SAPO-34 was prepared using DEA, aluminum isopropoxide, phosphoric acid and TEOS as the organic template, sources of Aluminum, Phosphor, and Silicate, respectively. Finally, the modified zeolite was combined with SAPO-34's gel.
Results: 20 different catalysts due to D-Optimal design were synthesized and the nanocomposite with 50 weight percent of SAPO-34, 4 hours Crystallization and early Clinoptilolite precipitation showed the highest relative crystallinity, partly high BET surface area and hierarchical structure.
Conclusion: Different analysis illustrated the existence of both components. The most important property alteration of nanocomposite was the increment of pore mean diameters and reduction in pore volumes in comparison with free SAPO-34. Due to low price of Clinoptilolite, the new catalyst develops the economy of the process. Using this composite, according to formation of multi-sized pores located hierarchically on the surface of the catalyst and increased surface area, significant amounts of Ethylene and Propylene, in comparison with free SAPO-34, were produced, as well as deactivation time that was improved.
Methanol to olefins conversion, SAPO-34/clinoptilolite, hydrothermal, nanocomposite design, response surface methodology, D-optimal design.
Faculty of Chemical Engineering, Amirkabir University of Technology, Tehran Polytechnic, P.O. Box 15875-4413, Hafez Ave., Tehran, Faculty of Chemical Engineering, Amirkabir University of Technology, Tehran Polytechnic, P.O. Box 15875-4413, Hafez Ave., Tehran, Faculty of Chemical Engineering, Amirkabir University of Technology, Tehran Polytechnic, P.O. Box 15875-4413, Hafez Ave., Tehran, Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran