Oxidative Dehydrogenation of Methanol on Chromium Oxide/Montmorillonite K10 Catalysts |
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Authors: | Maged Samir Ghattas |
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Affiliation: | Petroleum Refining Division , Egyptian Petroleum Research Institute (EPRI) , Nasr City, Cairo, Egypt |
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Abstract: | Abstract Methanol conversion was carried out on a mesoporous material—chromia/montmorillonite K10 (MK10)—in a pulse microcatalytic system. Methanol was converted to formaldehyde and ethylene by two different mechanisms. Methanol dehydrogenation increases by increasing reaction temperature (300–400°C) and as chromia loading decrease. On the other hand, the dehydration of methanol occurs at a higher temperature (400–500°C) and as chromia loading increase, 3–18% Cr. Redox and exposed nonredox Cr3+ are responsible for formaldehyde formation. There is a relationship between increased C2H4 production and the increase of Cr6+ phase according to the acidity of chromia catalysts 34 and 76 μL tert-Butylamine/g catalyst for 3% Cr and 18% Cr, respectively. Formaldehyde formation is diffusionally controlled at high temperatures (400–500°C) and kinetically controlled at a lower reaction temperature (300–400°C), while methanol dehydration to ethylene is surface reaction controlled at 400–500°C. |
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Keywords: | chromia catalysts methanol conversion surface acidity |
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