Kinetic Studies of Carbon Dioxide Reforming of Methane over Ni−Co/Al−Mg−O Bimetallic Catalyst

Abstract

The kinetics of CO2 reforming with CH4 over a Ni−Co/Al−Mg−O bimetallic catalyst was investigated in a fixed bed reactor at a temperature range of 650−750 °C and the partial pressures of CO2 and CH4 ranging from 30 to 190 kPa. Owing to the simultaneous occurrence of the CO2 reforming reaction and the reverse water−gas shift reaction (RWGS) in the system, the apparent activation energies with respect to reactant consumption and product formation were found different and they are 69.4 and 25.9 kJ/mol for CH4 and CO2 consumption and 85.1 and 61.8 kJ/mol for H2 and CO formation, respectively. It was also found that the reforming rate in terms of CH4 consumption was less sensitive to CO2 partial pressures but had stronger dependence on CH4 partial pressures. At a constant CH4 partial pressure, the increase in CO2 partial pressure did not cause significant change in the reforming rate, whereas at a constant CO2 partial pressure the reforming rate increased with the increase in CH4 partial pressure. The increase in extra CO2 at a constant CH4 pressure led to decreases in hydrogen (H2) formation but increase in carbon monoxide (CO) formation due to the simultaneous occurrence of the reverse water-gas shift reaction. A Langmuir−Hinshelwood (L–H) model was also developed assuming that the dissociation of CH4 and the reaction between the carbon species and the activated carbon dioxide are the rate determining steps over the Ni–Co/Al–Mg–O. It satisfactorily fits the experimental data as well.

Kinetic study of methane reforming with carbon dioxide over NiCeMgAl bimodal pore catalyst

“…Comparison of data between Figures and indicates that the CH 4 consuming rate was more sensitive to CH 4 partial pressure than to CO 2 partial pressure. At a constant CO 2 partial pressure, the reforming rate increased fast with the increase in CH 4 partial pressure; while at a constant CH 4 partial pressure, the increase in CO 2 partial pressure cause a relative slow rise in the reforming rate, which is in conformity with the results on a Ni‐Co/Al‐Mg catalyst but contrasts with the observations on Ni/La 2 O 3 catalyst and Ni‐Cr‐Al metallic foam with Ru/Al 2 O 3 catalyst …”

A review on coke management during dry reforming of methane

“…Even though Oyama and coworkers [17] reported the process as uneconomical for hydrogen production because Revisiting coke management in dry reforming of methane O. Muraza and A. Galadima of the presence of reverse water gas shift reaction, which consumes hydrogen in the reaction network, the huge reserves of methane and CO 2 are very strategic for dry reforming technology [18,19]. In this development, dry reforming of methane has been applied at the large scale by Midrex, for steel industry [20].…”

Kinetic assessment of dry reforming of methane on Pt + Ni containing composite of fluorite-like structure

“…However, we shall suppose another reason of the inflexion observed for the plots at the There is no generally accepted kinetic model available for CO 2 reforming of CH 4 . A LangmuirHinshelwood type of model has been most often used in the kinetic studies of CO 2 reforming of CH 4[1,[54][55][56][57][58]. For the Pt+Ni/PrSmCeZrO/YSZ nanocomposite catalyst, a kind of Pt-Ni interactions certainly exists, which is responsible for variations in the dissociative adsorption capacity of methane and carbon dioxide.…”