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 = 200 L, k = 0.05 min⁻¹Q = 10 L/minCA0​ = 1.5 mol/LCA​ = ?

A liquid-phase first-order reaction A → B (k = 0.05 min⁻¹) runs in a 200 L continuous stirred-tank reactor (CSTR). The feed enters at 10 L/min with CA0 = 1.5 mol/L. The density is constant and the reactor is at steady state. Find the outlet concentration CA.

V = 200 LQ = 10 L/mink = 0.05 min⁻¹CA0 = 1.5 mol/L
CA = mol/L
2.Easy
V = 100 L, k = 0.3 min⁻¹Q = 50 L/minCA0​ = 2.5 mol/LCA​ = ?

A liquid-phase first-order reaction A → B (k = 0.3 min⁻¹) runs in a 100 L continuous stirred-tank reactor (CSTR). The feed enters at 50 L/min with CA0 = 2.5 mol/L. The density is constant and the reactor is at steady state. Find the outlet concentration CA.

V = 100 LQ = 50 L/mink = 0.3 min⁻¹CA0 = 2.5 mol/L
CA = mol/L
3.Medium
Q = 40 L/minCA0​ = 1 mol/LCA​ = ?V = 200 L, k = 0.05 min⁻¹

A liquid-phase first-order reaction A → B (k = 0.05 min⁻¹) runs in a 200 L plug-flow reactor (PFR). The feed enters at 40 L/min with CA0 = 1 mol/L. The density is constant and the reactor is at steady state. Find the outlet concentration CA.

V = 200 LQ = 40 L/mink = 0.05 min⁻¹CA0 = 1 mol/L
CA = mol/L
4.Medium
Q = 40 L/minX = 60%V = ?, k = 0.25 min⁻¹

A first-order liquid-phase reaction A → B with k = 0.25 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 60% conversion of A.

Q = 40 L/mink = 0.25 min⁻¹X = 60%
V = L
5.Hard
V = 500 LV = 500 LQ = 80 L/minX = ?

A first-order liquid-phase reaction (k = 0.25 min⁻¹) runs in two equal CSTRs in series, each of 500 L. The feed rate is 80 L/min, the density is constant and the reactors are at steady state. Find the overall conversion X in percent.

V = 500 L (×2)Q = 80 L/mink = 0.25 min⁻¹
X = %
6.Hard
Q = 10 L/minX = ?V = 100 L

A first-order liquid-phase reaction (k = 0.08 min⁻¹) runs in a 100 L plug-flow reactor (PFR) fed at 10 L/min. The density is constant and the reactor is at steady state. Find the conversion X in percent.

V = 100 LQ = 10 L/mink = 0.08 min⁻¹
X = %

Answer key

  1. 1. CA = 0.75 mol/L
  2. 2. CA = 1.563 mol/L
  3. 3. CA = 0.7788 mol/L
  4. 4. V = 146.6 L
  5. 5. X = 84.77 %
  6. 6. X = 55.07 %

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