Kinetics of the catalytic cracking of naphtha over ZSM-5 zeolite: effect of reduced crystal size on the reaction of naphthenes

Content Provider	Semantic Scholar
Author	Konno, Hiroki Ohnaka, Ryota Nishimura, Jun-Ichi Tago, Teruoki Nakasaka, Yuta Masuda, Takao
Copyright Year	2014
Abstract	The catalytic cracking of model naphthenes (cyclohexane and methylcyclohexane) over ZSM-5 zeolites of different crystal sizes (macro- and nano-ZSM-5) was examined at reaction temperatures ranging from 748 to 923 K under atmospheric pressure, focusing on the associated reaction rate constants and activation energies. The catalytic cracking was found to follow first-order kinetics with respect to the naphthene concentrations and the activation energies for cyclohexane and methylcyclohexane cracking over nano-ZSM-5 were determined to be 119 and 116 kJ mol−1, respectively. In order to elucidate the rate-limiting step in the cracking process, the Thiele modulus and the effectiveness factor obtained from cracking over the two ZSM-5 zeolites were evaluated. Cracking with nano-ZSM-5 proceeded under reaction-limiting conditions, whereas the reaction over macro-ZSM-5 at 923 K took place under transition conditions between reaction- and diffusion-limiting. Nano-ZSM-5 was applied to the catalytic cracking of a model naphtha and the results demonstrated that this catalyst was both effective and stable and generated a high yield of light olefins.
Starting Page	4265
Ending Page	4273
Page Count	9
File Format	PDF HTM / HTML
DOI	10.1039/C4CY00733F
Alternate Webpage(s)	https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/59518/1/Tago_accept.pdf
Alternate Webpage(s)	https://doi.org/10.1039/C4CY00733F
Volume Number	4
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article