The irreversible gas-phase reaction A→cat B is carried out adiabatically over a packed bed of solid catalyst particles. The reaction is first order in the concentration of A on the catalyst surface
−rAs′=k′CAs
The feed consists of 50% (mole) A and 50% inerts, and enters the bed at a temperature of 300 K. The entering volumetric flow rate is 10 dm³/s (i.e., 10000 cm3/s). The relationship between the Sherwood number and the Reynolds number is
Sh = 100 Re1/2
As a first approximation, one may neglect pressure drop. The entering concentration of A is 1.0 M. Calculate the catalyst weight necessary to achieve 60% conversion of A for
a. isothermal operation.
b. adiabatic operation.
Additional information:

Transcribed Image Text:

Kinematic viscosity: u/p = 0.02 cm²/s Particle diameter: dp = 0.1 cm Superficial velocity: U = 10 cm/s Catalyst surface area/mass of catalyst bed: a = 60 cm²/g-cat Diffusivity of A: De = 10-2 cm²/s Heat of reaction: AHRX=-10000 cal/g mol A Heat capacities: CpA = CpB = 25 cal/g mol - K, Cps (solvent) = 75 cal/g mol. K k' (300 K) = 0.01 cm³/s. g-cat with E = 4000 cal/mol