Partial oxidation of methane on a nickel catalyst: Kinetic Monte-Carlo simulation study

Abstract

Kinetic Monte-Carlo simulation is applied to study the partial oxidation of methane over a nickel catalyst. Based on the Langmuir-Hinshelwood mechanism, the kinetic behavior of this reaction is analyzed and the results are compared with previous experiments. This system exhibits kinetic phase transitions between reactive regions with sustained reaction and poisoned regions without reaction. The fractional coverages of the adsorbed species and the production rates of H 2 , CO, H 2 O, and CO 2 are evaluated at steady state as functions of feed concentration of the methane and oxygen, and reaction temperature. The influence of lattice coordination number, diffusion, and impurities on the surface is also investigated. The simulation results are in good agreement with the experimental studies where such results are available. It is observed that when the lattice coordination number is increased to eight, the width of the reactive region increases significantly. Moreover, the phase transition becomes continuous. The diffusion of adsorbed O and H on the surface plays a measurable role in the reaction, increasing the maximum production rates as the diffusion rate increases. In systems with impurities, the production rates are greatly reduced and the phase transition is also changed from being abrupt to continuous.

RETRACTED: Computational Fluid Dynamics Modeling of the Catalytic Partial Oxidation of Methane in Microchannel Reactors for Synthesis Gas Production

“…The reaction mechanism has attracted increasing attention recently [15,16,[67][68][69]. The reaction may proceed through a combination of direct partial oxidation and steam reforming [39][40][41].…”

Development of Composite Materials by Combustion Synthesis Method for Catalytic Reforming of Methane to Synthesis Gas

“…2018 components of catalysts, relate to such promising methods [15][16][17][18][19]. The main advantages of these methods are: low energy costs, short synthesis times, no need for expensive equipment, the possibility of a onestage conversion of inorganic materials to final products using chemical reaction energy, an increase in non-stoichiometric phases of products due to high thermal gradient and rapid cooling rate [20][21][22].…”

Kinetic Monte-Carlo Simulation of Methane Steam Reforming over a Nickel Surface

“…In this simulation, lattice sizes of 64 × 64, 128 × 128, and 256 × 256 sites were examined under the same operating conditions, and it could be observed that the lattice size had no significant effect on the fractional coverages and rates of product formation, which is similar to the other works [34,[36][37][38]. Therefore, the lattice size of 64 × 64 sites was selected in this simulation study.…”

“…on the fractional coverages and rates of product formation, which is similar to the other works [34,[36][37][38]. Therefore, the lattice size of 64 × 64 sites was selected in this simulation study.…”

“…In the simulation, the kMC model defines the surface of the catalyst as a two-dimensional square lattice of L × L sites with periodic boundary conditions [34,48]. The lattice is in contact with an infinite reservoir of methane (CH 4 ) and steam (H 2 O), with fixed feed concentrations.…”