Learning Forum

[Anshul]

Hi all,

I am working of methanol steam reforming using packed bed. The main species involved in this are CH3OH, H2O, CO2, H2 and CO. Their reaction is shown in the image attached.

While selecting species order in mixture template, I am using this order:

CH3OH > H2O > CO2 > H2 > CO.

However, In FLUENT guide it is stated that the last species should be bulk (overall largest mass fraction) as as FLUENT solves for n-1 species only and for the last one it gives automatically.

How to chose this species as initially we have only two species CH3OH and H2O with certain mass fraction, that will get converted to other species like H2, CO2 and CO during reforming reaction.

I then ended up using N2 as last species as it is not involved in given reaction. But still, as at inlet we have 0.33 mole fraction CH3OH and 0.67 mole fraction of H2O, So, N2 will zero!. so how I should go ahead with this species order situation? Is adding N2 is valid even if it is not involved in reaction ?

[DrAmine]

Just provide the ballast specie the one which is not involved in any reactions. n

[DrAmine]

Is really facultative and is not a showstopper here to decide which specie to be considered as ballast one.n