Investigation on the light alkanes aromatization over Zn and Ga modified HZSM-5 catalysts in the presence of methane

• Published in: Fuel (Guildford) Vol. 219; no. C; pp. 331 - 339
• Main Authors: Li, Qingyin, Zhang, Fengqi, Jarvis, Jack, He, Peng, Yung, Matthew M., Wang, Aiguo, Zhao, Kai, Song, Hua
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2018; Elsevier BV; Elsevier
• Subjects: 09 BIOMASS FUELS; Alkanes; Aromatic compounds; Benzene; BTX; Catalysis; Catalysts; Co-aromatization; Coexistence; Gallium; Heptanes; Hydrocarbons; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Intermediates; Light alkane; Metals; Methane; Natural gas; Paraffin; Paraffins; Petrochemicals; Petrochemicals industry; Synergistic effect; Toluene; Xylene; Zeolites; Zinc; Zinc compounds; ZSM-5; Methane; Co-aromatization; BTX; ZSM-5; Light alkane
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2018.01.104

•Co-aromatization of long-chain alkane and methane is technically feasible.•Methane presence favors formation of benzene, toluene, and xylene (BTX).•Zinc and gallium loaded on ZSM-5 exhibit a synergetic effect on BTX formation.•Catalytic performance on co-aromatization is closely related to its physical properties. The catalytic co-aromatization of methane and paraffin-rich raffinate oil was investigated along with hexane, heptane and octane as its model compounds over zinc and gallium modified ZSM-5 zeolite catalysts. The benzene, toluene and xylene (BTX) components derived from light alkane aromatization were highly promoted with the assistance of methane. The co-existence of Zn and Ga metal species has a positive effect on the formation of BTX components, whereas the individual metal loaded catalyst resulted in the production of heavy aromatics, suggesting that zinc and gallium have a synergistic effect on the formation of BTX under the methane environment. When concerned with gaseous analysis, the introduced methane might interact with smaller intermediates and then transform into larger hydrocarbons. From the DRIFT observation, it was witnessed that the interaction between light alkane and methane occurred on the surface of the charged Zn-Ga/ZSM-5 catalyst. According to the comprehensive catalyst characterizations, the excellent catalytic performance may be closely associated with greatly dispersed metal species on the zeolite support, improved microporous characteristic, moderate Brönsted and increased Lewis acidic sites during the paraffin-rich liquid feedstock aromatization under methane environment. This research provides a promising pathway for the highly effective and profitable utilization of petrochemical resources and natural gas.