Continuous iC4/C4= Alkylation under iC4 Supercritical Conditions over K2.5H0.5PW12O40 and H-Beta Solid Acids

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• 作者：Ana Lilia Mota Salinas ; Dejin Kong ; Younes Ben Tâ ; arit ; and Nadine Essayem
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2004
• 出版时间：September 29, 2004
• 年：2004
• 卷：43
• 期：20
• 页码：6355 - 6362
• 全文大小：177K
• 年卷期：v.43,no.20(September 29, 2004)
• ISSN：1520-5045

文摘

The solid-acid-catalyzed iC₄/C₄⁼ alkylation reaction has been investigated in a continuous fixed-bed reactor in supercritical isobutane and compared with that in the liquid phase. Theperformances of heteropolyacids were compared with those of H-beta zeolites with differentSi/Al ratios. Over the two types of catalysts, enhanced catalyst lifetimes were observed whendense supercritical (SC) isobutane was used. It was observed that, when adequate solid acidcatalysts are used together with convenient experimental conditions, high alkylate yields (gramsof C₅⁺ per gram of C₄⁼) are obtained. This demonstrates that alkylation reactions might be theoperative pathways under supercritical iC₄ conditions. Otherwise, if the cracking activity underthe iC₄ SC phase is increased relative to that in the liquid phase, it is seen that, by using aconvenient catalyst of lower acid strength, as shown in the present study, one can partlycircumvent this drawback. With catalyst aging, the following successive steps are observed: iC₄self-alkylation-cracking/pure alkylation-cracking/multiple alkylation-cracking.