Consider the gas-phase chlorination of propylene with

to produce allyl chloride. The reaction network is as follows:

,

,

.
Propylene and allyl chloride are labelled species

and

, respectively.
The reaction rates are given by

,

,

.
These reaction rate expressions are postulated based on the following observation: step 1 is faster than step 3 at 500°C and step 3 occurs at temperature as low as 100°C, while steps 1 and 2 have negligible velocities.
Yield of allyl chloride versus conversion of propylene for the isothermal behavior of a plug-flow reactor is given by the following relationship:
This expression can be easily derived using the
Mathematica built-in command
DSolve, assuming product-free feed (i.e.,

and

). Indeed,

and

are subject to the following differential equation and initial condition:

and

.
This Demonstration provides insights into how temperature will affect the yield.