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    Copyright
    Preface
    Acknowledgments
    About the Author
    Nomenclature
    Ch. 1. Introduction to Separation Process Engineering
    Ch. 2. Flash Distillation
    Ch. 3. Introduction to Column Distillation
    Ch. 4. Binary Column Distillation: Internal Stage-by-Stage Balances
    Ch. 5. Introduction to Multicomponent Distillation
    Ch. 6. Exact Calculation Procedures for Multicomponent Distillation
    Ch. 7. Approximate Shortcut Methods for Multicomponent Distillation
    Ch. 8. Introduction to Complex Distillation Methods
    Ch. 9. Batch Distillation
    Ch. 10. Staged and Packed Column Design
    Ch. 11. Economics and Energy Conservation in Distillation
    Ch. 12. Absorption and Stripping
    Absorption and Stripping Equilibria
    McCabe-Thiele Solution for Dilute Absorption
    Stripping Analysis for Dilute Systems
    Analytical Solution for Dilute Systems: Kremser Equation
    Efficiencies
    McCabe-Thiele Analysis for More Concentrated Systems
    Column Diameter
    Dilute Multisolute Absorbers and Strippers
    Matrix Solution for Concentrated Absorbers and Strippers
    Irreversible Absorption and Co-Current Cascades
    Summary—Objectives
    References
    Homework
    Chapter 12 Appendix. Computer Simulations for Absorption and Stripping
    Ch. 13. Liquid-Liquid Extraction
    Ch. 14. Washing, Leaching, and Supercritical Extraction
    Ch. 15. Introduction to Diffusion and Mass Transfer
    Ch. 16. Mass Transfer Analysis for Distillation, Absorption, Stripping, and Extraction
    Ch. 17. Introduction to Membrane Separation Processes
    Ch. 18. Introduction to Adsorption, Chromatography, and Ion Exchange
    Appx. A. Aspen Plus Troubleshooting Guide for Separations
    Appx. B. Instructions for Fitting VLE and LLE Data with Aspen Plus
    Appx. C. Unit Conversions and Physical Constants
    Appx. D. Data Locations
    Answers to Selected Problems
    Index
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    Homework

    A. Discussion Problems

    A1.How can the direction of mass transfer be reversed as it is in a complete gas plant? What controls whether a column is a stripper or an absorber?
    A2.Why is the Murphree efficiency often lower in chemical absorption than in physical absorption? (What additional resistances are present?)
    A3.After reviewing Chapter 10, outline the method of determining the column diameter for an absorber or stripper in a packed column.
    A4.As the system becomes dilute, L/G→L/V, Y → y, and X → x. At what concentration levels could you safely work in terms of fractions and total flows instead of ratios and flows of solvent and carrier gas? What variable will this depend on? Explore numerically.
    A5.Which methods will give accurate results for concentrated, nonisothermal absorber (circle all correct answers)?

    1. McCabe-Thiele diagram

    2. Kremser equation

    3. Aspen Plus

    4. None of the above

    A6.A stripper is unable to obtain the specified purity of the outlet liquid. The outlet liquid concentration of the impurity can be decreased (which might allow one to reach or exceed the specified purity) by doing which of the following changes? Circle all correct answers. There are five correct answers—one in each pair (A,B,C,D,E). Note: Think of this as doing each change by itself and determine if it decreases the concentration of impurity in the outlet liquid.

    A.a. Increase inlet gas flow rate.
     b. Decrease inlet gas flow rate.
    B.c. Increase inlet liquid flow rate
     d. Decrease inlet liquid flow rate.
    C.e. Increase number of stages.
     f. Decrease number of stages.
    D.g. Increase column pressure.
     h. Decrease column pressure.
    E.i. Increase temperature of inlet gas and inlet liquid.
     j. Decrease temperature of inlet gas and inlet liquid.


    A7.Explain how the single assumption that “solutes are independent of each other” can specify more than one degree of freedom.
    A8.Develop your key relations chart for this chapter.

    B. Generation of Alternatives

    B1.The Kremser equation can be used for more than just determining the number of stages. List as many types of problems (where a different variable is solved for) as you can. What variables would be specified? How would you solve the equation?
    B2.Many other configurations of absorbers and strippers can be devised. For example, there could be two feeds. Generate as many as possible.
    B3.You want to use both co-current and countercurrent absorbers in a process. Sketch as many ways of doing this as you can think of. What are the advantages and disadvantages of each method?


      

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