Reforming of carbon monoxide mixture gas by water-gas shift reaction

Update: July 28, 2017
OpenFOAM 4.x

Case directory

$FOAM_TUTORIALS/multiphase/reactingTwoPhaseEulerFoam/RAS/bubbleColumnEvaporatingReacting

Summary

Model geometry Model geometry

We calculate how air containing carbon monoxide blown into water is reformed by the water-gas shift reaction CO\ + H2O\ \rightleftarrows\ CO2\ + H2 for 100 seconds. The calculation is performed as a two-dimensional problem with one mesh in the Z direction.

At initial state, the analysis domain is assumed to be half filled with water. Liquid water and gaseous air containing 10% carbon monoxide flow in from the region "inlet" at the bottom of the analysis region at a velocity of (0, 0.1, 0) m/s. The water evaporates into water vapor, and the carbon monoxide reacts with the water vapor to produce carbon dioxide and hydrogen, which flow from the region "outlet".

The properties of the chemical reactions are specified in the file "constant/reactions.gas" as follows.

species
(
    CO
    CO2
    H2
    H2O
    AIR
);

reactions
{
    waterGasShift
    {
        type        reversibleArrheniusReaction;

        reaction    "CO^0.93 + H2O^0.24 = CO2^0.69 + H2^1";

        A           1e8;
        beta        0.86;
        Ta          1e4;
    }
}

Here, the parameters A, β, and Ta correspond to the parameters of the Arrhenius equationk = A T^\beta \exp\left(-\frac{T_{\mathrm{a}}}{T}\right), which determines the chemical reaction rate k from the temperature T.

The meshes are as follows, and the number of mesh is 1875.

Mesh Meshes

The calculation result is as follows.

Carbon monoxide (CO.gas)
Air at final time (AIR.gas) Air at final time (AIR.gas)
Carbon monoxide at final time (CO.gas) Carbon monoxide at final time (CO.gas)
Water vapor at final time (H2O.gas) Water vapor at final time (H2O.gas)
Carbon dioxide at final time (CO2.gas) Carbon dioxide at final time (CO2.gas)
Hydrogen at final time (H2.gas) Hydrogen at final time (H2.gas)

It can be seen that the inflowing carbon monoxide is almost completely gone near the outlet due to the water-gas shift reaction.

Commands

cp -r $FOAM_TUTORIALS/multiphase/reactingTwoPhaseEulerFoam/RAS/bubbleColumnEvaporatingReacting bubbleColumnEvaporatingReacting
cd bubbleColumnEvaporatingReacting

blockMesh

setFields
decomposePar
mpirun -np 6 reactingTwoPhaseEulerFoam -parallel
reconstructPar

paraFoam

Calculation time

3 hours 50 minutes 26.14 seconds *Single, Inter(R) Core(TM) i7-2600 CPU @ 3.40GHz 3.40GHz

Reference