Effect of Water Pretreatment on Alumina-based Catalysts in Methanol Dehydration PDF Download

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Category : Aluminum oxide
Languages : en
Pages : 140

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Book Description
In this study, gamma-Al[subscript 2]O[subscript 3] and amorphous AlPO[subscript 4] were synthesized and tested in methanol dehydration reaction. Both gamma-Al[subscript 2]O[subscript 3] and AlPO[subscript 4] catalysts showed increasing of activity when temperature direction during reaction test changed from step-up (150>200>250>300) to step-down (300>250>200>150). The effect of the presence of water product was studied by pretreatment of AlPO[subscript 4] catalyst with water various conditions. FT-IR and FT-Raman results indicated formation of P-OH group on the pretreated catalysts, which was one of intermediate for methanol dehydration. Amine titration also showed increasing of both strength and amount of acid sites on surface of the treated catalysts. The appropriate temperature on AlPO[subscript 4] catalyst was determined to be 200-250 degrees celsius for 10% mol of water in 5,300 h[superscript -1] GHSV for 15 minutes. On the other hand, the presence of water at 100 degrees celsius pretreatment became AlPO[subscript 4] poison which indicated by TGA and FT-Raman that physisorbed water could block the adsorption of methanol on catalyst active sites instead.