Kinetics and mechanism of the oxidative dehydrogenation of n-butane over a SiO2-supported VMgO catalyst

• Norka Armas Universidad Central de Venezuela-Venezuela
• José Manuel López Nieto Universidad Central de Venezuela-Venezuela
• José Papa Universidad Central de Venezuela-Venezuela
• B. Solsona Universidad Polit í¨cnica de Valencia-España
• A Briceño Universidad Central de Venezuela-Venezuela

Abstract

An experimental study, and the corrresponding simulation, for the oxidative dehydrogenation of n-butane over a SiO2(30 wt%)-supported VMgO catalyst (with a Mg/V atomic ratio of 4 and a surface area, SBET, of 73 m2/g) is presented. Experimental data were obtained using a packed bed quartz tubular reactor operating under steady-state conditions, isothermal, and uniform flow conditions, varying the temperature within the range of 475-550°C, the contact time from 10 to 60 gcat/(moln-butane/h), the inlet molar fraction of n-butane from 2 to 8% and that of oxygen from 8 to 20%. The proposed model is based on a sound reaction scheme, with kinetics expression derived using the redox mechanism of Mars-Van Krevelen. The best fitting was obtained with a correlation coefficient of 0.8715 and a variance of 1.33 x10-3.