Derive the energy balance for a packed-bed membrane reactor. Apply the balance to the reaction in Problem P11-5A A ⇄ B + C
for the case when it is reversible with KC = 1.0 mol/dm³ at 300 K. Species C diffuses out of the membrane with kC = 1.5 s^–1.
(a) Plot and then analyze the concentration profiles for different values of KC when the reaction is carried out adiabatically.
(b) Repeat part (a) when the heat transfer coefficient is Ua = 30 J/s·kg-cat·K with T_a = 50°C.

Data From Problem P11-5A

The elementary, irreversible gas-phase reaction A → B + C is carried out adiabatically in a PFR packed with a catalyst. Pure A enters the reactor at a volumetric flow rate of 20 dm3/s, at a pressure of 10 atm, and a temperature of 450 K.
Additional information:

All heats of formation are referenced to 273 K.

1. Plot and then analyze the conversion and temperature down the plug-flow reactor until an 80% conversion (if possible) is reached. (The maximum catalyst weight that can be packed into the PFR is 50 kg.) Assume that ΔP = 0.0
2. Vary the inlet temperature and describe what you find.
3. Plot the heat that must be removed along the reactor (Q˙ vs. V) to maintain isothermal operation.
4. Now take the pressure drop into account in the PBR with ρb = 1 kg/dm³. The reactor can be packed with one of two particle sizes. Choose one.
α = 0.019/kg-cat for particle diameter D₁
α = 0.0075/kg-cat for particle diameter D₂
5. Plot and then analyze the temperature, conversion, and pressure along the length of the reactor. Vary the parameters α and P₀ to learn the ranges of values in
which they dramatically affect the conversion.

Transcribed Image Text:

CPA=40J/mol K CPB=25J/mol K CPC=15J/mol KHAo=-70kJ/mol HBo=-50kJ/mol HCo=-40kJ/mol