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Dehydroaromatization of methane in the absence of oxygen over supported W based catalysts

Kusmiyati, Kusmiyati and Saidina Amin, Nor Aishah (2004) Dehydroaromatization of methane in the absence of oxygen over supported W based catalysts. In: 18th Symposium of Malaysian Chemical Engineers (SOMChe) 2004, 13 - 14 Dec. 2004, UTP, Perak, Malaysia.

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Abstract

Dehydroaromatization of methane (DHAM) was studied over W-based catalysts with different types of supports, i.e. HZSM-5, Hβ, USY and A2O3. Among them, HZSM-5 showed the best support. The performance between W/HZSM-5 and W-H2SO4/HZSM-5 prepared using different conditions was further compared. Next, the effect of Si/Al ratio of W-H2SO4/HZSM-5 catalyst was also investigated. It was shown that the nature and dispersion of the tungsten species was dependent on the type of support, preparation condition as well as Si/Al ratio of HZSM-5. As a result, the catalyst activity and stability were strongly affected. W-H2SO4/HZSM-5 with Si/Al ratio=30 exhibited remarkable methane conversion and aromatic products due to the presence of a major component assigned to polytungsten species and tetrahedral monomeric. However, the effect of Si/Al ratio on W-H2SO4/HZSM-5 indicated that higher the Si/Al ratio lowerer the DHAM activity. This is attributed to lower amount of strong acid sites as revealed by TPD-NH3. This result suggests that in addition to polymeric and monomeric tungsten species, a proper amount of acid sites is needed to enhance the catalyst performance.

Item Type:Conference or Workshop Item (Paper)
Uncontrolled Keywords:Dehydro-aromatization, methane, supported tungsten species, W/HZSM-5
Subjects:T Technology > T Technology (General)
Divisions:Chemical and Natural Resources Engineering (Formerly known)
ID Code:6024
Deposited By: Norhani Jusoh
Deposited On:31 Jul 2008 10:24
Last Modified:01 Jun 2010 15:37

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