Abstract:
Aromatic synthesis from n-heptane using modified MFI-type zeolite catalysts were investigated. It was shown that gallium and zinc improved both the activity and selectivity of n-heptane aromatization. Gallium and zinc modification was achieved by incorporation method which simplified the catalyst preparation procedure. It has been found that H-Ga. Al-silicate having Si/Ga loading ratio of 100, Si/Al ratio of 40 and H-Zn.Al-silicate having Si/Zn loading ratio of 150, Si/Al ratio of 40 exerted considerably high selectivity for aromatics. This selectivity was comparable to that of Ga or Zn exchanged MFI with the same amount of Ga or Zn loading. However, the bimetalloaluminosilicate catalysts can be prepared in only one step crystallization and thus simplifies the catalyst preparation procedure. The influence of different reaction parameters such as reaction temperature, space velocity and stability were also studied. The selectivity for aromatic is maximum at 550 ํC and GHSV 2000 h-1 for 1 hour on stream. The activity of deactivated H-Ga.Al-silicate and H-Zn.Al-silicate can be restored via the regeneration at 550 ํC for 2 hours.
