I am doing my PG project in reforming methane with carbon dioxide to produce hydrogen and carbon monoxide.
CH
4+CO
2 2CO+2H
2 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
kads = e(-Ea/RT) P /(2πmkT)0.5
and the rate constant equation for desorption
kdes =A e(-Ea/RT)
the equation to find A the pre-eponential factor while calculated experimentally or Z collision frequency. I am using
Z = NavoσAB(8kBT/(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 * 10
12the k
des is calculated considering the hydrogen molecule will desorb the activated carbon.
k
des = 5.34 * 10
5I calculated the active sites per m
2 of carbon is 2.65 * 10
18the 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 CH
4 is calculated with the equation found from the web. is
R = kdes * 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.