The following reactions are to be carried out in a continuous flow system.

The reaction is liquid phase and carried out in 500 dm³ CSTR and the exit concentrations were found.

The entering flow rate of A is 25 mol/s and B is 50 mol/s at a temperature of 27C. The coolant temperature in the heat exchanger is constant at 350K, and the product of the overall heat transfer coefficient and the heat exchange area is 5000 cal/s�K.

(a)  If the activation energies are virtually zero (i.e. constant specific reaction rates, ks), what would be the temperature of the CSTR?

(b)  Outline how you would solve the problem if the activation energies were not zero and the concentrations were not measured.

Solution

Solution

a)   Activation energy = E = 0

Use energy balance:

*Note: the DH_Rxij must match the r_ij
For Example:

Expanded:
Reaction 1:
Reaction 2:
Reaction 3:
Solve for T:
Plugging in numbers:

Now calculate the numerator

Now calculate the denominator

 b)   If activation energies � 0

T and Ci unknown How to solve? Use the combined mole balance and rate law for each species to determine Ci: Example, for A:

Apply energy balance as in part a:

Solve using Polymath

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