[marshalrj1986]

I am doing my PG project in reforming methane with carbon dioxide to produce hydrogen and carbon monoxide.

CH₄+CO₂ 2CO+2H₂

I am doing the project using matlab. The catalyst used is activated carbon. the order of methane is 0.5 and carbon dioxide is 0 in the presence of activated carbon. I understand the reaction is a adsorption isotherm reaction. for adsorption the rate constant equation i got is

k_ads = e^(-E_a/RT) P /(2πmkT)^0.5

and the rate constant equation for desorption

k_des =A e^(-E_a/RT)

the equation to find A the pre-eponential factor while calculated experimentally or Z collision frequency. I am using

Z = N_avoσ_AB(8k_BT/(πμ))^0.5

the experimental conditions I consider are
Ea for adsorption = 4.55 kJ/mol
Ea for desorption = 14.5 kJ/mol
T = 1273K
P = 1 bar
by calculation the values i got are

k_ads = 1.5 * 10¹²

the k_des is calculated considering the hydrogen molecule will desorb the activated carbon.

k_des = 5.34 * 10⁵

I calculated the active sites per m² of carbon is 2.65 * 10¹⁸

the thing worrying in me is i found in a journal paper that the conversion percentage of methane over the activated carbon is 90% at 1273K and what i get is too high.

the rate of surface reaction of CH₄ is calculated with the equation found from the web. is

R = k_des * Θⁿ

that is same as the desorption rate of the hydrogen from the surface. is it correct.
I am in a need to know if the equations being used and value of Ea are correct.
if there is an equation to find the activation energy from ΔH_r.