A gas-phase reaction is being carried out in a 5-cm-diameter tubular reactor that is 2 m in length. The velocity inside the pipe is 2 cm/s. As a very first approximation, the gas properties can be taken as those of air (kinematic viscosity = 0.01 cm²/s), and the diffusivities of the reacting species are approximately 0.005 cm²/s.
a. How many tanks in series would you suggest to model this reactor?
b. If the second-order reaction A + B → C + D is carried out for the case of equimolar feed, and with C_A0 = 0.01 mol/dm3, what conversion can be expected at a temperature for which k = 25 dm³/mol·s?
c. How would your answers to parts (a) and (b) change if the fluid velocity was reduced to 0.1 cm/s? Increased to 1 m/s?
d. How would your answers to parts (a) and (b) change if the superficial velocity was 4 cm/s through a packed bed of 0.2-cm-diameter spheres?
e. How would your answers to parts (a) through (d) change if the fluid was a liquid with properties similar to water instead of a gas, and the diffusivity was 5 = 10^–6 cm²/s?