The differential equation for a PFR with catalyst is :

Assuming that the reaction is elementary since we are not told otherwise, the reaction rate is defined as :

through stoichiometry, this becomes:

Substituting the reaction rate back into the differential equation gives :

which can be integrated from X=0 when W=0 to X=X when W=W :

to give :

Placing the known values into the equation :

Solving gives a conversion of :

Back to Heterogeneous Example 1