P8-4 Consider the following system of gas-phase reactions: 1/2 A-X ry=kick2 k, = 0.004 mol/dm)2 min AB=k_CA kz=0.3 min A Y ry=k,ci k;=0.25 dm /mol-min 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 27C. The reaction system is to be operated at 27C and 4 atm. Pure A enters the system at a volumetric flow rate of 10 dm min. (a) Sketch the instantaneous selectivities (Sax, Sny, and Sexy=1/(x+ry)) as a function of the con- centration of CN (b) Consider a series of reactors. What should be the volume of the first reactor? (e) 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 max- imize Sexy? Suppose that E = 20,000 cal/mol, E, = 10,000 cal/mol, and E; = 30,000 cal/mol. What tempera- ture would you recommend for a single CSTR with a space time of 10 min and an entering concen- tration of A of 0.1 mol/dm?? (g) If you could vary the pressure between 1 and 100 atm, what pressure would you choose