An experimental kinetic model for the oxidative coupling of methane using a bench‐scale reactor

Abstract

The aim of this work is to develop a kinetic model for the oxidative coupling of methane (OCM) based on the gas‐hourly space velocity (GHSV) and methane‐to‐oxygen ratio. The experiments were carried out in a bench‐scale tubular‐fixed bed reactor, using 30 g of perovskite titanate as the reaction catalyst. Different GHSVs (3000–6000 h−1) and methane‐to‐oxygen ratios (2,2.5 and 3) were selected. A mechanism was assumed in which the consumption rate of methane is always twice the production rate of C2 hydrocarbons. A power‐law model was assumed for rate of reaction in terms of partial pressure of oxygen and methane. Using a linear regression analysis, the kinetic model was determined. Comparison of the calculated rate of reaction with the experimentally measured data confirmed the accuracy and applicability of the developed model under various reaction conditions. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.

Kinetics investigation of direct natural gas conversion by oxidative coupling of methane

“…Kinetics of OCM reaction to C 2 hydrocarbons has been studied extensively based on the various reaction mechanisms (Bistolfi et al, 1992;Lehmann and Baerns, 1992;Yaghobi et al, 2008;Arutyunov et al, 1997;Wolf, 1992;Vereshchagin and Ross, 1995;Couwenberg et al, 1996a;Peil et al, 1991;Zeng et al, 2001;Amorebieta and Colussi, 1995). Indeed, kinetics of OCM reaction is very complicated in terms of proposed mechanism since it involves several chemical species (Kao et al, 1997;Su et al, 2003;Couwenberg et al, 1996b;Xin et al, 2008).…”

“…Theoretical simulations are possible using such parameters, and rather remarkable coincidence with the experimental results has been obtained. The selectivity for C 2 molecules (ethane and ethylene) is poor without a catalyst; however, these studies are useful to evaluate the contribution of gas phase reactions to the reaction with a catalyst, especially under high temperatures and pressure (Laidler, 1965;Zanthoff and Baerns, 1990;). Fig.…”

“…Power rate law expression of C 2 (ethane and ethylene) and C 1 (CO and CO 2 ) formation This is a typical style of reaction engineering, which is simplistic and can be easily applied to process design. This could be the most practical approach when the best catalyst is selected (Ali Emesh and Amenomiya, 1986;Santamaria et al, 1991;Al-Zahrani, 2001;Yaghobi and Ghoreishy, 2008). Al-Zahrani (2001) used the two-phase theory which considers the fluidized bed reactor to consist of a bubble phase and a dense phase.…”

Perovskite catalysts for oxidative coupling of methane improved by Y‐doping

“…Recently, the direct chemical conversion process has received great attention, in which methane is directly converted into high value‐added products, such as ethylene, aromatic hydrocarbons, and methanol 8–11 . Because the oxidative coupling of methane (OCM) was firstly proposed by Keller in 1982, 12 many studies on the OCM have been reported in the past 40 years 13–17 . However, this reaction has not yet reached the target of 35% C 2 yield and 90% C 2 selectivity; 18 thus, it still cannot be used as a successful industrial process for ethylene production.…”

“…[8][9][10][11] Because the oxidative coupling of methane (OCM) was firstly proposed by Keller in 1982, 12 many studies on the OCM have been reported in the past 40 years. [13][14][15][16][17] However, this reaction has not yet reached the target of 35% C 2 yield and 90% C 2 selectivity; 18 thus, it still cannot be used as a successful industrial process for ethylene production.…”