Catalytic conversion of light alkanes to aromatics by metal-containing HZSM-5 zeolite catalysts—A review

Synthesis of Zeolite Catalysts Containing Zn and Ga for Aromatization of <i>n</i>-Hexane

“…The aromatization of light alkanes including ethane, propane, and n-hexane is an important process for producing value-added aromatic compounds, especially benzene, toluene, and xylenes (BTX), because the aromatization process can be adapted to use natural gas, to meet the increased demands for raw chemicals in the petrochemical industry in recent decades. For the aromatization of alkanes, various metal-loaded zeolite catalysts based on ZSM-5 1) 14) , MCM-22 15) , ZSM-11 16) , and L zeolite 17) 21) have been extensively developed. In particular, Zn-or Ga-containing ZSM-5 provides high catalytic activities and selectivities for aromatic compounds because of the combination of the dehydrogenation over the metal species and Brønsted acidity of the ZSM-5 zeolite 1),3),5),6), 10) .…”

Ex‐situ catalytic fast pyrolysis of low‐rank coal over HZSM ‐5 and modified Mg/ HZSM ‐5 catalysts

“…Several studies have examined the effectiveness of zeolite catalysts (HZSM‐5, USY, and SBA‐15) in the catalytic cracking of coals 21,23‐25 . HZSM‐5 has the strongest Brønsted acid sites that promote the aromatization reaction to convert hydrocarbon materials to BTX 26‐28 . Chareonpanich et al examined the catalytic pyrolysis of Millmerran coal using metal‐loaded zeolite catalysts 29 .…”

“…The USY zeolite catalyst demonstrated remarkable catalytic activity, such as hydrogenation and cracking, which led to the highest level of BTX production (14 wt%) compared to that obtained by other metal oxide catalysts. Nevertheless, USY zeolites tend to restrain the highest selectivity to BTX because of additional reactions, such as hydride transfer or protolytic cracking 27 . This might inhibit the availability of the active sites and obstruct the dispersion of bulky molecules into the pore structure.…”

“…Nevertheless, USY zeolites tend to restrain the highest selectivity to BTX because of additional reactions, such as hydride transfer or protolytic cracking. 27 This might inhibit the availability of the active sites and obstruct the dispersion of bulky molecules into the pore structure. Zeolites have high deactivation for cracking the macromolecules of coal having a large acidic component during the catalytic pyrolysis.…”

“…21,[23][24][25] HZSM-5 has the strongest Brønsted acid sites that promote the aromatization reaction to convert hydrocarbon materials to BTX. [26][27][28] Chareonpanich et al examined the catalytic pyrolysis of Millmerran coal using metal-loaded zeolite catalysts. 29 The USY zeolite catalyst demonstrated remarkable catalytic activity, such as hydrogenation and cracking, which led to the highest level of BTX production (14 wt%) compared to that obtained by other metal oxide catalysts.…”