1. Lecture 20 Thursday 3/20/08 Multiple Reactions with Heat Effects

2. User Friendly Equations Relate T and X or F i

3. Heat Exchange Elementary gas phase reaction carried out in a PBR The feed consists of both inerts I and Species A with the ratio of inerts to the species A being 2 to 1. (a)Adiabatic. Plot X, X e, T and the rate of disappearance as a function of V up to V = 40 dm 3. (b)Constant T a. Plot X, X e, T, T a and Rate of disappearance of A when there is a heat loss to the coolant and the coolant temperature is constant at 300 K for V = 40 dm 3. How do these curves differ from the adiabatic case? (c)Variable T a Co-Current. Plot X, X e, T, T a and Rate of disappearance of A when there is a heat loss to the coolant and the coolant temperature varies along the length of the reactor for V = 40 dm 3. The coolant enters at 300 K. How do these curves differ from those in the adiabatic case and part (a) and (b)? (d)Variable T a Counter Current. Plot X, X e, T, T a and Rate of disappearance of A when there is a heat loss to the coolant and the coolant temperature varies along the length of the reactor for V = 20 dm 3. The coolant enters at 300 K. How do these curves differ from those in the adiabatic case and part (a) and (b)?

4. Mole Balance(1) Rate Law(2) (3) (4)

5. Stoichiometry(5) (6) Parameters(7) – (15)

6. Energy Balance Adiabatic and  C P = 0 (16A) Additional Parameters (17A) & (17B) Heat Exchange (16B)

7. A. Constant T a (17B) T a = 300 Additional Parameters (18B – (20B): T a,, Ua, B. Variable T a Co-Current (17C) C. Variable T a Counter Current (18C) Guess T a at V = 0 to match T a = T ao at exit, i.e., V = V f

13. User Friendly Equations Relate T and X or F i

22. Heat Exchange Elementary liquid phase reaction carried out in a PFR The feed consists of both inerts I and Species A with the ratio of inerts to the species A being 2 to 1.

23. Multiple reactions with heat effects Multiple Rxns Mole balances – every species (no conversion!) Rates – rate laws net/relative rates Stoichiometry – Heat effects –

24. Rate is given for 2C, but ΔH R is given for 2A! Make sure it is in respect to A; A needs a coefficient of 1!!!!!!! 1) Mole balance:

25. 2) Rate laws: 3) Stoich: 4) Heat effects: Parameters: