(a) Example 14–1. How large would the error term be in Equation E14-1.4 if τA: = 0.1? τk =...

(a) Example 14–1. How large would the error term be in Equation E14-1.4 if τA: = 0.1? τk = 1?τk= 10?

(b) Example 14–2. Vary D„, k, U, and L. To what parameters or groups of parameters (e.g., kL2/D„) would the conversion be most sensitive? What if the first-order reaction were carried out in tubular reactors of different diameters, but with the space time, x, remaining constant? The diameters would range from a diameter of 0.1 dm to a diameter of 1 m for kinematic viscosity  υ= µ/ρ = 0.01 cm2/s, U = 0.1 cm/s, and DAB = 105 cm2/s. How would your conversion change? Is there a diameter that would maximize or minimize conversion in this range?

(c)Example 14–3. (1) Load the reaction and dispersion program from the COMSOL CD-ROM. Vary the Damkohler number for a second-order reaction using the Aris−Taylor approximation (part (b) in Example 14–3). (2) Vary the Peclet and Damkohler numbers for a second-order reaction in laminar flow. What values of the Peclet number affect the conversion significantly?

(d) Example 14–4. How would your answers change if the slope was 4 mitr1 and the intercept was 2 in Figure E14-4.2?

(e) Example 14–5. Load the Living Example Polymath Program. Vary a and (3 and describe what you find. What would be the conversion if α = 0.75 and β = 0.15?

(f) What if you were asked to design a tubular vessel that would minimize dispersion? What would be your guidelines? How would you maximize the dispersion? How would your design change for a packed bed?

(g) What if someone suggested you could use the solution to the flow-dispersion-reactor equation, Equation (14–27), for a second-order equation by linearizing the rate law by lettering Under what circumstances might this be a good approximation? Would you divide CA0 by something other than 2? What do you think of linearizing other non-first-order reactions and using Equation (14–27)? How could you test your results to learn if the approximation is justified?

(h) What if you were asked to explain why physically the shapes of the curves in Figure 14–3 look the way they do, what would you say? What if the first pulse in Figure 14.1(b) broke through at  = 0.5 and the second pulse broke through at  = 1.5 in a tubular reactor in which a second-order liquid-phase reaction

2A.→ B + C

was occurring? What would the conversion be if x = 5 min, CA0 = 2 mol/dm3, and k = 0.1 dm3/mol•min?