TITLE:
Thermodynamics of the Reaction CO + H2O = CO2 + H2
AUTHORS:
Slavko Đurić, Marko Jarić, Žarko Bojić, Zdravko Božičković
KEYWORDS:
Temperature, Thermodynamic Functions, Equilibrium Constant
JOURNAL NAME:
Journal of Applied Mathematics and Physics,
Vol.13 No.3,
March
13,
2025
ABSTRACT: The paper presents the values of thermodynamic functions
ΔH, ΔG, ΔS
reactions
CO+
H
2
O=
CO
2
+
H
2
in the temperature range 298 - 1500 K. In the considered temperature interval, the reaction is exothermic (
ΔH<0
) with a negative entropy change (
ΔS<0
). Free reaction enthalpy (
ΔG
) is determined by the ratio of the enthalpy and entropy terms. This means that the reaction is
CO+
H
2
O=
CO
2
+
H
2
thermodynamically favorable at lower temperatures. Above 1092 K the free reaction enthalpy is positive (
ΔG>0
) so the reaction enters thermodynamically unfavorable conditions. At lower reaction temperatures the equilibrium reaction constant
CO+
H
2
O=
CO
2
+
H
2
is much larger than one (
K
p
≫1
) which means that the products of the reaction are in excess of the reactants, i.e. the reaction is shifted in the direction of building up the products of the reaction. In an equilibrium mixture with a stoichiometric ratio of reactants
CO:
H
2
O=1:1
and at an ambient temperature of 298 K, the degree of conversion of reactants into products is 99.69% and at 1500 K it is 38.08%.