Chemical Kinetic Model Essay
Chemical Kinetic Models
Simplified Global Chemical Kinetic Model
In order to compare the two reactors used in our experiment, a simplified global kinetic model was used to describe the DRM reaction behavior in different plasma reactor. This model was already used by authors in the field of pollutant removal by using a plasma reactor [15, 21–23]. It is generally accepted that free radical processes are the main mechanisms in non-equilibrium plasma reaction [21, 24-25].
The chemical kinetics model was based on the following step process:
The reactant molecules CH4 or CO2 (S) are attacked by active species R (radicals and Ar active species) produced by plasma discharges: S + R →products The reaction rate would be: r = k1 R.S, with k1: reaction rate constant, R = radical concentration, S = (CH4 + CO2) concentration. The …show more content…
Table 3 reports the obtained values of rR and k2/k1 for CH4 and CO2. It shows that the production rate of radicals depends strongly on the nature of reactant, while for CH4 it is quite twice the value for CO2. From the k2/k1 ratio value, it is possible to indicate the dominating reaction: The reaction between actives species and reactant driving to products formation, or the active species loss reaction by recombination or desexcitation.
In corona and glow discharge plasma, For CO2, the value of k2/k1 ratio (0.24, 0.21) respectively; indicates that the reaction of active species is favored compared to their loss. For CH4 (k2/k1 ratio: 0.33, 0.31) respectively, the loss of active species is quite as important as the reaction, so the recombination of active species originated from methane occurs more readily than from carbon dioxide. CH4 and CO2 conversions can be foresee according to the energy transfer to the gas (P×τ). The β values for both reactants were calculated for different dilution factors by Ar from the 〖β(s〗_0) linearity law (Table 3), and introduced in the following
Simplified Global Chemical Kinetic Model
In order to compare the two reactors used in our experiment, a simplified global kinetic model was used to describe the DRM reaction behavior in different plasma reactor. This model was already used by authors in the field of pollutant removal by using a plasma reactor [15, 21–23]. It is generally accepted that free radical processes are the main mechanisms in non-equilibrium plasma reaction [21, 24-25].
The chemical kinetics model was based on the following step process:
The reactant molecules CH4 or CO2 (S) are attacked by active species R (radicals and Ar active species) produced by plasma discharges: S + R →products The reaction rate would be: r = k1 R.S, with k1: reaction rate constant, R = radical concentration, S = (CH4 + CO2) concentration. The …show more content…
Table 3 reports the obtained values of rR and k2/k1 for CH4 and CO2. It shows that the production rate of radicals depends strongly on the nature of reactant, while for CH4 it is quite twice the value for CO2. From the k2/k1 ratio value, it is possible to indicate the dominating reaction: The reaction between actives species and reactant driving to products formation, or the active species loss reaction by recombination or desexcitation.
In corona and glow discharge plasma, For CO2, the value of k2/k1 ratio (0.24, 0.21) respectively; indicates that the reaction of active species is favored compared to their loss. For CH4 (k2/k1 ratio: 0.33, 0.31) respectively, the loss of active species is quite as important as the reaction, so the recombination of active species originated from methane occurs more readily than from carbon dioxide. CH4 and CO2 conversions can be foresee according to the energy transfer to the gas (P×τ). The β values for both reactants were calculated for different dilution factors by Ar from the 〖β(s〗_0) linearity law (Table 3), and introduced in the following