Chapter 2: Conversion and Reactor Sizing


Example

Using the Ideal Gas Law to Calculate CA0 and FA0

The entering molar flow rate for a gas is

\( F_{A0} = v_{0} C_{A0} = v_{0} \frac{y_{A0} P_{0}}{RT_{0}} \)

where CA0=

entering concentration, mol/dm3

yA0=

entering mole fraction of A

P0=

entering total pressure, e.g., kPa

PA0=

yA0P0 = entering partial pressure of A, e.g., kPa

T0=

entering temperature, K

v0=

volumetric flow rate

R=

Ideal Gas Constant ( e.g \( R = 8.314 \, \frac{\text{kPa} \cdot \text{dm}^3}{\text{mol} \cdot \text{K}} \); see Appendix B)

The size of the reactor will depend on the flow rate, reaction kinetics, reactor conditions, and desired conversion. Let's first calculate the entering molar flow rate.


A gas of pure A at 830 kPa (8.2 atm) enters a reactor with a volumetric flow rate, v0, of 2 dm3/s at 500 K. Calculate the entering concentration of A, CA0, and the entering molar flow rate, FA0.

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