Reactor sizing (CSTR & PFR) worksheet with answers

Free printable Reactor sizing (CSTR & PFR) worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
V = ?, k = 0.3 min⁻¹Q = 25 L/minX = 90%

A first-order liquid-phase reaction A → B with k = 0.3 min⁻¹ is carried out in a continuous stirred-tank reactor (CSTR) fed at 25 L/min. The density is constant and the reactor is at steady state. Find the reactor volume V in litres for 90% conversion of A.

Q = 25 L/mink = 0.3 min⁻¹X = 90%
V = L
2.Easy
τ = ?k = 0.08 min⁻¹X = 50%

A first-order liquid-phase reaction with k = 0.08 min⁻¹ runs in a CSTR at steady state. What space time τ is needed to reach 50% conversion?

k = 0.08 min⁻¹X = 50%
τ = min
3.Medium
Q = 40 L/minX = 70%V = ?, k = 0.5 min⁻¹

A first-order liquid-phase reaction A → B with k = 0.5 min⁻¹ is carried out in a plug-flow reactor (PFR) fed at 40 L/min. The density is constant and the reactor is at steady state. Find the reactor volume V in litres for 70% conversion of A.

Q = 40 L/mink = 0.5 min⁻¹X = 70%
V = L
4.Medium
Q = 10 L/minX = 95%V = ?, k = 0.08 min⁻¹

A first-order liquid-phase reaction A → B with k = 0.08 min⁻¹ is carried out in a plug-flow reactor (PFR) fed at 10 L/min. The density is constant and the reactor is at steady state. Find the reactor volume V in litres for 95% conversion of A.

Q = 10 L/mink = 0.08 min⁻¹X = 95%
V = L
5.Hard
V = 200 LQ = 80 L/minX = ?

A first-order liquid-phase reaction (k = 0.3 min⁻¹) runs in a 200 L CSTR fed at 80 L/min. The density is constant and the reactor is at steady state. Find the conversion X in percent.

V = 200 LQ = 80 L/mink = 0.3 min⁻¹
X = %
6.Hard
V = 400 LQ = 10 L/minX = ?

A first-order liquid-phase reaction (k = 0.2 min⁻¹) runs in a 400 L CSTR fed at 10 L/min. The density is constant and the reactor is at steady state. Find the conversion X in percent.

V = 400 LQ = 10 L/mink = 0.2 min⁻¹
X = %

Answer key

  1. 1. V = 750 L
  2. 2. τ = 12.5 min
  3. 3. V = 96.32 L
  4. 4. V = 374.5 L
  5. 5. X = 42.86 %
  6. 6. X = 88.89 %

Full step-by-step solutions: practise this topic on examproblems.com.