1. Chemical Reaction Engineering (CRE) is the field that studies the rates and mechanisms of chemical reactions and the design of the reactors in which they take place. Lecture 12

2. Lecture 12 – Tuesday 2/15/2011 Multiple Reactions Selectivity and Yield Series Reactions Complex Reactions 2

3. Series: A → B → C Parallel: A → D, A → U Independent: A → B, C → D Complex: A + B → C + D, A + C → E With multiple reactors, either molar flow or number of moles must be used (no conversion!) 3

4. InstantaneousOverall There are two types of selectivity and yield: Instantaneous and Overall. Selectivity Yield 4

5. To maximize the selectivity of D with respect to U run at high concentration of A and use PFR. Example:Desired Product: Undesired Product: 5

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7. FlowBatch 7 A) Mole Balance of each and every Species

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9. Example: A → B → C (1) A → B k 1 (2) B → C k 2 9

10. V=V 0 (constant batch) 10

11. Laws Net rates 11 Relative rates

12. example: A → B → C (1) A → B (2) B → C t t opt CiCi A B C 12

13. Relative: Laws: 13

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15. Using the integrating factor, at t = 0, C B =0 15

16. what is the optimal ? 16

17. Laws: Net: Relative: 17

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19. 19 Find that gives maximum concentration of B

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21. End of Lecture 12 21

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31. Many metabolic reactions involve a large number of sequential reactions, such as those that occur in the coagulation of blood. Cut → Blood → Clotting Figure A. Normal Clot Coagulation of blood (picture courtesy of: Mebs, Venomous and Poisonous Animals, Medpharm, Stugart 2002, Page 305) 31

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33. Cut A + B C D E F Clot 33