The reaction A → B is carried out in a differential packed-bed reactor at different temperatures, flow rates, and particle sizes. The results shown in Figure P15-3B were obtained.

Reaction rates in a catalyst bed.
In the graph, the vertical axis represents the reaction rate ranging from 0 to 20 in increments of 5 and the horizontal axis represents flow rate ranging from 0 to 4500 in increments of 500. Horizontal lines are plotted for d subscript p of 0.03 centimeters, 0.1 centimeters, 0.3 centimeters and 0.8 centimeters. The curve plotted for reaction rate shows a value of 2.2 for flow rate of 500 (same value for d subscript p equals 0.3 and 0.8) and increases gradually to a value of 9 (400 K, d subscript p equals 0.8 centimeters) and becomes constant.
a. What regions (i.e., conditions d_p, T, F_T0) are external mass transfer–limited?
b. What regions are reaction rate–limited?
c. What region is internal-diffusion-controlled?
d. What is the internal effectiveness factor at T = 400 K and d_p = 0.8 cm?

Transcribed Image Text:

mol g-cates 20 15 10 5 0 500 1000 1500 2000 2500 3000 3500 4000 4500 Fro(mol/s) 400 k, d, = 0.03 cm 400K, d,-0.1 cm 400K, d,=0.6 cm 400 K d,=0.8 cm 300K, d,- 9.3 om 300 K, d.= 0.8 cm