Catalytic Cracking and Coking of Supercritical n-Dodecane in Microchannel Coated with HZSM-5 Zeolites

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• 作者：Fanxu Meng ; Guozhu Liu ; Shudong Qu ; Li Wang ; Xiangwen Zhang ; Zhentao Mi
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2010
• 出版时间：October 6, 2010
• 年：2010
• 卷：49
• 期：19
• 页码：8977-8983
• 全文大小：382K
• 年卷期：v.49,no.19(October 6, 2010)
• ISSN：1520-5045

文摘

To improve the cracking rate of supercritical hydrocarbon fuels, HZSM-5 coating was prepared over the inner surface of microchannels reactors by the washcoating method. Thermal or catalytic cracking of n-dodecane, a model compound of hydrocarbon fuels, was experimentally investigated in the stainless steel microchannel coated with HZSM-5 coatings under supercritical conditions (p > 4 MPa, T > 450 °C). It is found that cracking of n-dodecane was enhanced more than 100% by HZSM-5 coatings in 30 min reaction durations at 525 and 550 °C despite gradual deactivations of catalytic activities due to conversion coke from pyrolysis and acid-catalyzed reaction. Cokes deposited on the microchannels with and without HZSM-5 coating were characterized by scanning electron microscopy (SEM) and temperature-programmed oxidation (TPO), indicating that HZSM-5 coating effectively reduces formation of filamentous cokes and its damage on the micro channel surface by shielding surface metals when the temperature is higher than 600 °C.