# Economic/Statistic Problems

Butene is cracked in the presence of steam at an absolute pressure of 3.0 bar and a temperature
of 500K according to the reaction:
C4H8 → C4H6 + H2
which follows a second order kinetics with respect to butene. 100 mol s-1 of butene and 200 mol
s-1 of steam are fed together to the reactor. If the operation is isothermal and the rate constant is
12.0 m3mol-1 s-1 and assuming that the volumetric flow does not change linearly with conversion.
Task 1 – Design a reactor to achieve 4a% of butene conversion (where a is the digital from your
group number, i.e., if your group number is B1, a will be 1, so 41% of butene conversion is the
target).
Make sure you cover the following aspects:
1) Description of the process: Theoretical background and reactor choice. (10 marks)
2) Derive the design equation in term of the butene conversion. (20 marks)
3) Determine the reactor volume by solving the design equation. (20 marks)
4) Detailed sketch of the reactor. (10 marks)
5) Mechanical design and overall reactor costing. (10 marks)
Task 2 – Write a Matlab program to evaluate the dependence of the reactor volume on the butene
conversion. Your Matlab program needs to be able to calculate the reactor volume automatically
for the range of butene conversion from a% (where a is the digital from your group number) to
100% with an interval of 1%, (20 marks)
AND
plot the variation of the reactor volume with the butene conversion. (10 marks) 