This is a model of the partial oxidation of o-xylene in a large excess of oxygen in a 1.5 m long plug flow reactor.

The first-order rate expression:

,

where

is rate of reaction (

),

is the pre-exponential factor in the rate constant (1/s),

is activation energy (kJ/mol),

is the ideal gas constant (kJ/[mol K]),

is absolute temperature in the reactor (K),

is pressure (atm),

is the ideal gas constant (

),

is the molar flow rate of the reactant o-xylene (kmol/s), and

is the total molar flow rate of the feed (kmol/s).

Mole balance as a function of reactor length:

,

where

is distance down the PFR (m),

is the cross section area of the PFR (

), and

is the PFR radius (m).

Energy balance as a function of length:

,

,

,

where

and

are simplification terms,

is the temperature of heat transfer fluid surrounding the reactor (K),

is heat of reaction (kJ/kmol),

is mass flow rate (kg/s),

is the mass heat capacity of gas in reactor (kJ/[kg K]) and

is the overall heat transfer coefficient (

).

At the PFR inlet (

)

and

, where

is the feed temperature (K) and

is the mole fraction of reactant in the feed.

The screencast video at [2] explains how to use this Demonstration.

[1] J. B. Rawlings and J. G. Ekerdt,

*Chemical Reactor Analysis and Design Fundamentals*, Madison, WI: Nob Hill Publishing, 2002 pp. 323–326.