8-4A Consider the following system of gas-phase reactions:B is the desired product, and X and Y are foul pollutants that are expensive to get rid of. The specific reaction rates are at 27°C. The reaction system is to be operated at 27°C and 4 atm. Pure A enters the system at a volumetric flow rate of 10 dm3/min. (a) Sketch the instantaneous selectivities (SB/X, SB/Y, and SB/XY = rB/(rX + rY)) as a function of the concentration of CA. (b) Consider a series of reactors. What should be the volume of the first reactor?(c) What are the effluent concentrations of A, B, X, and Y from the first reactor?(d) What is the conversion of A in the first reactor?(e) If 99% conversion of A is desired, what reaction scheme and reactor sizes should you use to maximize SB/XY?(f) Suppose that E1 = 20,000 cal/mol, E2 = 10,000 cal/mol, and E3 = 30,000 cal/mol. What temperature would you recommend for a single CSTR with a space time of 10 min and an entering concentration of A of 0. 1 mol/dm3?(g) If you could vary the pressure between 1 and 100 atm, what pressure would you choose?
