TY - JOUR
T1 - Non-oxidative aromatization and ethylene formation over Ga/HZSM-5 catalysts using a mixed feed of methane and ethane
AU - Lee, Byung Jin
AU - Hur, Young Gul
AU - Kim, Do Huei
AU - Lee, Seong Ho
AU - Lee, Kwan Young
N1 - Funding Information:
We thank Elizabeth Bickel for technical feedback on this manuscript. This research was supported by the C1 Gas Refinery Program through the National Research Foundation of Korea (NRF)and funded by the Ministry of Science, ICT & Future Planning (2016M3D3A1A01913252). Also, this work was supported by a National Research Foundation of Korea (NRF)grant funded by the Korean Government (MSIP)(NRF-2015R1A2A1A13001856).
PY - 2019/10/1
Y1 - 2019/10/1
N2 - The effects of the total number of acid site and gallium loading on Ga/HZSM-5 catalysts for non-oxidative aromatization and ethylene formation were investigated using a mixed feed of methane and ethane, analogous to shale gas. When the acid sites of the catalysts increased with the change in the Si/Al ratio, the total conversion of hydrocarbons and the total yield of BTX and ethylene increased, but the selectivity of ethylene tended to decrease. This suggests that the Brønsted acid sites of catalysts is responsible for the dispersion of gallium species and the aromatization of intermediate. On the other hand, when the gallium loading of HZSM-5(15)catalysts increased from 1.0 to 7.0 wt%, the ethylene yield increased, but the BTX yield decreased. The excessive gallium loading resulted in the drastic change of textural properties and the dealumination leading to the decrease of Brønsted acid sites, which caused the decrease of BTX selectivity and the increase of ethylene selectivity. In addition, with the increase of the gallium loading of the HZSM-5(15)catalysts, while the ethane conversion did not change, the methane conversion and ethylene yield gradually increased. This suggests that the dehydrogenative coupling of methane was promoted by the gallium species formed at high gallium loading catalysts such as gallyl ion. Characterizations by N2 adsorption/desorption, ICP-AES, XRD, XPS, TEM, NH3-TPD, pyridine FT-IR, H2-TPR, AAS, and 27Al NMR were used to investigate the relationship between the catalytic performance for aromatization and ethylene formation.
AB - The effects of the total number of acid site and gallium loading on Ga/HZSM-5 catalysts for non-oxidative aromatization and ethylene formation were investigated using a mixed feed of methane and ethane, analogous to shale gas. When the acid sites of the catalysts increased with the change in the Si/Al ratio, the total conversion of hydrocarbons and the total yield of BTX and ethylene increased, but the selectivity of ethylene tended to decrease. This suggests that the Brønsted acid sites of catalysts is responsible for the dispersion of gallium species and the aromatization of intermediate. On the other hand, when the gallium loading of HZSM-5(15)catalysts increased from 1.0 to 7.0 wt%, the ethylene yield increased, but the BTX yield decreased. The excessive gallium loading resulted in the drastic change of textural properties and the dealumination leading to the decrease of Brønsted acid sites, which caused the decrease of BTX selectivity and the increase of ethylene selectivity. In addition, with the increase of the gallium loading of the HZSM-5(15)catalysts, while the ethane conversion did not change, the methane conversion and ethylene yield gradually increased. This suggests that the dehydrogenative coupling of methane was promoted by the gallium species formed at high gallium loading catalysts such as gallyl ion. Characterizations by N2 adsorption/desorption, ICP-AES, XRD, XPS, TEM, NH3-TPD, pyridine FT-IR, H2-TPR, AAS, and 27Al NMR were used to investigate the relationship between the catalytic performance for aromatization and ethylene formation.
KW - BTX
KW - Dehydrogenative coupling of methane
KW - Ethylene
KW - Ga/HZSM-5
KW - Non-oxidative aromatization
KW - Shale gas
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U2 - 10.1016/j.fuel.2019.05.014
DO - 10.1016/j.fuel.2019.05.014
M3 - Article
AN - SCOPUS:85065520562
VL - 253
SP - 449
EP - 459
JO - Fuel
JF - Fuel
SN - 0016-2361
ER -