Problem 12.11-1 (Geankoplis)

G2 5CHEA - JEAN RAYNELL BELLO

Problem 12.11-1

Crystallization of Ba(NO3)2. A hot solution of Ba(NO3)2 from an evaporator contains 30.6 kg Ba(NO3)2/100 kg H2O and goes to a crystallizer, where the solution is cooled and Ba(NO3)2 crystallizes. On cooling, 10% of the original water present evaporates. For a feed solution of 100 kg total, calculate the following:

a. The yield of crystals if the solution is cooled to 290 K (17°C), where the solubility is 8.6 kg Ba(NO3)2/100 kg total water.

b. The yield if cooled instead to 283 K, where the solubility is 7.0 kg Ba(NO3)2/100 kg total water.

Problem Set in Crystallization 2

3

Problem 12.11-1

CrystallizerFeed

100 kg solution30.6 kg Ba(NO3)2/100 kg H2O

W = 10% H2O

x kg solution

8.6 kg Ba(NO3)2/100 kg H2O

C kg Ba(NO3)2

crystals

The solution is cooled to 290 K

Problem Set in Crystallization

4

Problem 12.11-1

H2O BALANCE:

Ba(NO3)2 BALANCE:

Problem Set in Crystallization

5

Problem 12.11-1

CrystallizerFeed

100 kg solution30.6 kg Ba(NO3)2/100 kg H2O

W = 10% H2O

x kg solution

7.0 kg Ba(NO3)2/100 kg H2O

C kg Ba(NO3)2

crystals

The solution is cooled to 283 K

Problem Set in Crystallization

6

Problem 12.11-1

H2O BALANCE:

Ba(NO3)2 BALANCE:

Problem Set in Crystallization