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Batch Stoichiometric Table

Batch Stoichiometric Table. Species. Symbol. Initial. Change. Remaining. A. A. B. B. C. C. D. D. Inert. I. -------. ____________. ________. and. where. Concentration: Batch Systems. Constant Volume Batch: Note:              if the reaction occurs in the liquid phase

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Batch Stoichiometric Table

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  1. Batch Stoichiometric Table Species Symbol Initial Change Remaining A A B B C C D D Inert I ------- ____________ ________ and where

  2. Concentration: Batch Systems Constant Volume Batch: Note:              if the reaction occurs in the liquid phase                                                or       if a gas phase reaction occurs in a rigid (e.g., steel) batch reactor Then etc. If then And we have –rA=f(X)

  3. Flow System Stoichiometric Table Species Symbol Initial Change Remaining A A B B C C D D Inert I ____________ ________ where and

  4. Concentration: Liquid Flow System • Flow Stystem: • Liquid Phase Flow System: • etc. If the rate of reaction were then we would have This gives us -rA = f(X). Consequently, we can use the methods discussed in Chapter 2 to size a large number of reactors, either alone or in series.

  5. Concentration: Gas Flow System THEN Note that the reaction is: A + (b/a)B - (c/a)C + (d/a)D IF the reaction rate is given by -rA = k CA2 CB THEN with

  6. Multiple Reactions Use molar flow rates and concentrations; DO NOT use conversion! Types of Multiple Reactions • Series Reactions • Parallel Reactions • Complex Reactions: Series and Parallel • Independent

  7. Selectivity and Yield InstantaneousOverall Selectivity Yield: Example: (1) desired product , rD=k1CA2CB (2) undesired product , rU=k2CACB

  8. Another example about Selectivity and Yield (1) desired product , rD=k1CA2CB (2) undesired product , rU=k2CACB (3) then SD/U1/U2 CA

  9. Algorithm for Multiple Reactions

  10. Mole Balances

  11. Net Rate of Reaction for Species A

  12. Series Reactions , t=0 CA=CA0

  13. Series Reactions

  14. Elementary Multiple Reactions

  15. Case 1:Liquid Phase Reaction in a CSTR

  16. Case 1:Liquid Phase Reaction in a CSTR

  17. Case 1:Liquid Phase Reaction in a CSTR

  18. Polymath Solution

  19. Polymath Solution

  20. Polymath Solution

  21. Elementary Multiple Reactions

  22. Example: Liquid Phase Reaction

  23. Example: Liquid Phase Reaction

  24. Example: Liquid Phase Reaction

  25. Example: Liquid Phase Reaction

  26. Multiple Reactions — Gas Phase Use Molar Flow Rates!!!

  27. The Algorithm

  28. The Algorithm (given)

  29. The Algorithm

  30. Heterogeneous Catalytic Reaction 1-External diffusion of reactants towards the external surface of the catalyst pellet 2-Internal diffusion of reactants into the pores of the catalyst pellet 3- Adsorption of reactants on the active sites 4- Surface reaction 5- Desorption of products from active sites into the pore volume of the catalyst pellet 6- Internal diffusion of products through the pores of the catalyst pellet towards the external surface of the catalyst pellet 7- External diffusion of products to the bulk of the fluid

  31. Molecular Adsorption

  32. Molecular Adsorption

  33. Steps of Catalytic Reaction B B

  34. B D C A B D C A + D C D C Steps of Catalytic Reaction B B B A + C + D

  35. Example: Catalytic Reaction to Improve the Octane Number of Gasoline Focusing on the second reaction:

  36. Example: Catalytic Reaction to Improve the Octane Number of Gasoline

  37. Example: Catalytic Reaction to Improve the Octane Number of Gasoline

  38. Different Surface Mechanisms

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