Presentation1
- 1. Presented By Mohsin Ali (2011-MS-CH-68)
- 2. Exercise 7.7 The following cost data, which include operating cost and depreciation of capital investment, pertain to Exercise 7.1. Determine by finding the total cost for each of the 14 possible sequences: The best The second-best The worst sequence sequence sequence Are the heuristics of Section 7.4 in agreement with the results based on costs?
- 3. Cost Data Split Cost ($/yr) Split Cost ($/yr) C3/B1 15,000 C3,B1,NB/B2 510,000 B1/NB 190,000 C3,B1/NB,B2 254,000 NB/B2 420,000 C3/B1,NB,B2 85,000 B2/C5 32,000 B1,NB,B2/C5 94,000 B1,NB/B2,C5 530,000 C3,B1/NB 197,000 B1/NB,B2,C5 254,000 C3/B1,NB 59,000 B1,NB/B2 500,000 C3,B1,NB,B2/C5 95,000 B1/NB,B2 247,000 C3,B1,NB/B2,C5 540,000 NB,B2/C5 64,000 C3,B1/NB,B2,C5 261,000 NB/B2,C5 460,000 C3/B1,NB,B2,C5 90,000
- 4. Feed Properties Component Feed Flow Rate Approx. Realtive (lbmol/hr) Volatility Relative to C5 Propane (C3) 10 8.1 Butene-1 (B1) 100 3.7 n-Butene (NB) 341 3.1 Butene-2 isomers (B2) 187 2.7 N-Pentane (C5) 40 1.0
- 5. C3 C3 B1 Separation B1 NB B2 Train NB C5 B2 C5
- 6. Number of Possible Sequences Here, P= Number of Products= 5 Hence, Ns = Number of Possible Sequences = 14
- 7. Sequence # 1 C3 B1 NB B2 C3 B1 NB B2 C5 B1 NB NB B2 B2 B2 C5 C5 C5 C5 Total Cost = $817,000
- 8. Sequence # 2 C3 c3 B1 C3 C3 NB B1 C3 B1 B2 NB B1 NB B2 C5 C5 B2 NB B1 Total Cost = $836,000
- 9. Sequence # 3 C3 B1 NB B1 NB C3 B2 B1 NB B2 NB B1 C5 B2 NB B2 C5 C5 B2 Total Cost = $851,000
- 10. Sequence # 4 C3 B1 C3 B1 B1 NB C3 NB B1 B2 NB B2 C5 B1 NB B2 C5 B2 NB Total Cost = $870,000
- 11. Sequence # 5 C3 B1 NB NB B2 C3 B1 NB B2 B1 C5 NB NB B2 B2 C5 C5 C5 B2 Total Cost = $828,000
- 12. Sequence # 6 C3 B1 B1 NB B1 B2 NB C3 B1 NB B2 B1 C5 NB B2 C5 C5 B2 NB Total Cost = $874,000
- 13. Sequence # 7 C3 B1 NB C3 B1 NB C3 B2 B1 NB B2 C5 B1 NB NB B2 B2 C5 B2 Total Cost = $847,000
- 14. Sequence # 8 C3 B1 C3 B1 C3 NB B1 C3 NB B2 B1 NB B2 C5 B1 NB C5 B2 NB Total Cost = $854,000
- 15. Sequence # 9 C3 C3 B1 NB C3 B1 NB B1 B2 C5 NB B2 C5 B2 C5 Total Cost = $760,000
- 16. Sequence # 10 C3 C3 B1 B1 C3 NB B1 NB B2 B2 C5 NB B2 C5 C5 Total Cost = $768,000
- 17. Sequence # 11 C3 C3 B1 NB B1 B2 NB C5 B2 C5 Total Cost = $784,000
- 18. Sequence # 12 C3 B1 C3 B1 NB NB B2 B2 C5 C5 Total Cost = $821,000
- 19. Sequence # 13 C3 B1 C3 B1 NB B1 B2 NB C5 NB B2 B2 C5 C5 Total Cost = $842,000
- 20. Sequence # 14 C3 C3 B1 C3 B1 NB B1 NB C3 B2 B1 NB NB B2 B2 C5 C5 B2 Total Cost = $784,000
- 21. Sequence # 9 C3 C3 B1 NB C3 B1 NB B1 B2 C5 NB B2 C5 B2 C5 Total Cost = $760,000
- 22. Sequence # 10 C3 C3 B1 B1 C3 NB B1 NB B2 B2 C5 NB B2 C5 C5 Total Cost = $768,000
- 23. Sequence # 6 C3 B1 B1 NB B1 B2 NB C3 B1 NB B2 B1 C5 NB B2 C5 C5 B2 NB Total Cost = $874,000
- 24. Now we willanalyze the three sequences in terms of Heuristics
- 25.
- 26. Heuristic # 1: Removethermally unstable, corrosive, or chemically reactive components early in the sequence. C3 C3 B1 NB C3 B1 NB B1 B2 C5 NB B2 C5 B2 C5
- 27. Sequence # 1 C3 B1 NB B2 C3 B1 NB B2 C5 B1 NB NB B2 B2 B2 C5 C5 C5 C5
- 28. Heuristic # 1: Remove thermally unstable, corrosive, or chemically reactive components early in the sequence. C3 C3 B1 NB C3 B1 NB B1 B2 C5 NB B2 C5 B2 C5
- 29. Heuristic # 2: Remove final products one by one as distillates (the direct sequence). C3 C3 B1 NB C3 B1 NB B1 B2 C5 NB B2 C5 B2 C5
- 30. Heuristic # 3: Sequence separation points to remove, early in the sequence, those components of greatest molar percentage in the feed. C3 C3 C3 B1 NB 341 lbmol/hr B1 NB B1 B2 C5 NB B2 C5 B2 187 lbmol/hr C5 40 lbmol/hr
- 31. Heuristic # 4: Sequence separation points in the order of decreasing relative volatility so that the most difficult splits are made in the absence of the other components. C3 8.1 C3 C3 B1 NB 3.1 B1 NB B1 B2 C5 NB B2 C5 B2 2.7 C5
- 32. Heuristic # 5: Sequenceseparation points to leave last those separations that give the highest-purity products. C3 C3 B1 NB C3 B1 NB B1 B2 C5 NB B2 C5 B2 C5
- 33. Heuristic # 6: Sequence separation points that favor near equimolar amounts of distillate and bottoms in each column. C3 9% 16% C3 C3 B1 NB 65% B1 NB B1 91% B2 C5 93% NB B2 C5 84% B2 35% C5 7%
- 34.
- 35. Heuristic # 1: Remove thermally unstable, corrosive, or chemically reactive components early in the sequence. C3 C3 B1 B1 C3 NB B1 NB B2 B2 C5 NB B2 C5 C5
- 36. Heuristic # 2: Remove final products one by one as distillates (the direct sequence). C3 C3 B1 B1 C3 NB B1 NB B2 B2 C5 NB B2 C5 C5
- 37. Heuristic # 3: Sequence separation points to remove, early in the sequence, those components of greatest molar percentage in the feed. C3 C3 B1 187 lbmol/hr B1 C3 NB B1 NB B2 B2 C5 NB 341 lbmol/hr B2 C5 C5
- 38. Heuristic # 4: Sequence separation points in the order of decreasing relative volatility so that the most difficult splits are made in the absence of the other components. C3 8.1 C3 B1 3.7 B1 C3 NB B1 NB B2 B2 C5 NB 3.1 B2 C5 C5
- 39. Heuristic # 5: Sequenceseparation points to leave last those separations that give the highest-purity products. C3 C3 B1 B1 C3 NB B1 NB B2 B2 C5 NB B2 C5 C5
- 40. Heuristic # 6: Sequence separation points that favor near equimolar amounts of distillate and bottoms in each column. C3 3% C3 23% 66% B1 B1 NB C3 97% B1 NB B2 B2 82% C5 NB 77% B2 34% C5 C5 18%
- 41. Conclusion In termsof cost, the best sequence is sequence #9, the second best is sequence #10 and the worst one is sequence #6. Although the Sequences 9 & 10 are best in terms of cost but they follow the heauristics to a minor extend.
- 42. THANKS FOR THE ATTENTION