CE 407 Separations

Registration number: 16375

Prerequisites: CE 304 (Chemical Engineering Thermodynamics), CE 318 (Transport Processes II)

Credits: 3

Dr. David Courtemanche, 309A Furnas Hall, 645-0650, djcourte@buffalo.edu
Zoom Meeting Link: https://buffalo.zoom.us/j/4543279676?pwd=M0JHOUc4cW9kVWRKSS91ckduZ3VSdz09

Dr. Miao Yu, 504 Furnas Hall, 645-9302, myu9@buffalo.edu

Class Time and Location: Tuesday and Thursday, 9:30 to 10:50 am in 04 Knox Hall

Office hours:
djc Mondays and Wednesdays at 1:00 pm--2:00 pm in 309A Furnas Hall, or by arrangement (send email to arrange a meeting time) OPEN DOOR POLICY - djc will be happy to answer questions outside of office hours; students should feel free to email anytime with questions or stop by 203A Furnas Hall

my Tuesday 3:00 to 4:00 pm and Thursday 1:00 to 2:00 pm in 504 Furnas Hall, or by arrangement (students are encouraged to send email to arrange meeting time) .

Course description: Staged operations of distillation, absorption, leaching, and extraction. Phase equilibria and application of equilibrium data to calculational methods provide knowledge of solution methods and limitations for binary and multicomponent systems.

Required textbook: McCabe WL, Smith JC, Harriott P. 2005. Unit Operations of Chemical Engineering, 7th ed. McGraw-Hill, New York. Denoted by "MSH" below.

Supplementary textbooks:
Treybal RE. 1981. Mass Transfer Operations, 3rd ed. McGraw-Hill, New York. Denoted by "T" below.
Dohert MF, Malone MF. 2001. Conceptual Design of Distillation Systems. McGraw-Hill, New York. Denoted by "DM" below.

Summaries of lectures, and materials pertaining to each, are posted here.

Lect. Date Lecturer Description Pertinent are...
Text Notes Hmwk
L01 8/29
djc/my Introduction to course. Introduction to textbook. Introduction to gas absorption. Rigorous calculation allowing for evaporation of liquid. Simplified calculation neglecting evaporation of liquid ("the usual approximations").
MSH pp. 521-525 Lecture 01
Single-stage absorption
L02 8/31
djc Improving a gas absorption operating by adding stages; why countercurrent contact is best. Operating line, equilibrium curve, McCabe-Thiele diagram, counting of stages.
MSH pp. 643-653 Lecture 02
Countercurrent contact
Absorption tower example (everything except minimum liquid flow rate)
L03 9/05
djc Absorption factor method (Kremser equation). Absorption operations, including minimum liquid flow rate. Stripping operations, including minimum gas flow rate.
MSH pp. 653-660 Lecture 03
Absorption tower example (calculation of minimum liquid flow rate)
Stripping tower example
L04 9/07
djc Saturated vapor pressure and relative volatility. Binary vapor-liquid equilibria and phase diagrams. MSH pp. 663-666, 737-742 Lecture 04
L05 9/12
djc Graphical method for binary flash distillation. Analytical method for binary and multicomponent flash distillation. Why a column improves product purities relative to flash distillation. Column mass balances. Percent recovery.
MSH pp. 666-681 Lecture 05
Binary distillation introduction
Binary distillation column flows exampleFlash distillation example
L06 9/14
djc McCabe-Thiele diagram: rectifying section operating line, feed line, stripping section operating line, counting of stages, feed stage location.
MSH pp. 681-694 Lecture 06
Binary distillation McCabe-Thiele method
Binary distillation tray efficiency (pp. 1-11)
Binary distillation McCabe-Thiele examples
Binary distillation McCabe Thiele 1925
Binary distillation Murphree 1925
Binary distillation further calcs and design (p. 1)
L07 9/19
djc Partial versus total condensers. Minimum number of stages, Fenske equation. Minimum and optimum reflux ratio. Use of overall and Murphree tray efficiency.
Effective Equilibrium Excel Calculation
MSH pp. 674-675, 687-691,712-722 Lecture 07
Binary distillation McCabe-Thiele method (p. 6)
Binary distillation further calcs and design (pp. 2-3, 5-6)
Binary distillation nearly pure products examples
Binary distillation enthalpy balance examples
L08 9/21
djc Nearly pure products: use of the Kremser equation for distillation. Enthalpy balance calculations: liquid and vapor mixture enthalpies.
MSH pp. 694-701 Lecture 08
Binary distillation McCabe-Thiele method (p. 6)
Binary distillation further calcs and design (pp. 2-3, 5-6)
Binary distillation nearly pure products examples
Binary distillation enthalpy balance examples
L09 9/26
djc Enthalpy balance calculations: Condenser and reboiler duties. Design of columns: vapor pressure drop, downcomer level and tray spacing; flooding velocity and column diameter.
MSH pp. 701-712, 718-724 Lecture 09
Binary distillation tray efficiency (pp. 12-13)
Binary distillation further calcs and design (pp. 4-5, 7-11)
Binary distillation enthalpy balance examples
L10 9/28
djc Batch distillation.
MSH pp. 724-727 Lecture 10
Binary batch distillation theory
Binary batch distillation examples
L11 10/03
djc Introduction to multicomponent distillation: light and heavy keys, splits, non-distributed and distributed components, column sequencing. Short-cut methods: Fenske equation for minimum number of stages, Underwood's method for minimum reflux ratio, Gilliland correlation for number of ideal stages at operating reflux ratio.
MSH pp. 742-752, 757-759
DM pp. 144-145, 290-291
Lecture 11
L11 Example Problems
Multicomponent distillation column sequencing example
Multicomponent distillation short-cut examples
L12 10/05
djc Degrees of Freedom in a distillation process. Tray-to-tray calculations. Design versus performance models. Collection of VLE and LLE data!
MSH pp. 752-756
DM pp. 115-124, 144-145, 147
Lecture 12
Multicomponent distillation tray-to-tray examples
Multicomponent distillation performance models
VLE and LLE data DECHEMA series
L13 10/12
my Definition of leaching, everyday example (making tea), theory for countercurrent contact. Problem-solving procedure, solved example problem.
MSH pp. 764-772 Lecture 13
Leaching example
Leaching example
Leaching more examples
Leaching shanks process
L14 10/17
my Introduction to liquid extraction: basic process and uses, liquid-liquid equilibria, ternary phase diagrams, mass balances for a mixing step. Single-stage liquid extraction.
MSH pp. 772-783
T pp. 433-446
Lecture 14
Liquid extraction introduction
Liquid extraction single-stage examples
L15 10/19
my Multistage crosscurrent extraction. Multistage countercurrent extraction: overall mass balances.
MSH pp. 772-783
T pp. 446-448, 450-451
Lecture 15
Liquid extraction countercurrent examples (problems 1 and 2)
Exam 1 10/24
Covers Lectures 1-12, Homework 1-6
L16 10/26
my Multistage countercurrent extraction: Hunter-Nash and McCabe-Thiele methods for counting stages.
MSH pp. 772-783
T pp. 450-453
Lecture 16
Liquid extraction countercurrent examples (problems 3(b), 4, 5(b) and 6)
Video of LLE Countercurrent Example 3b
L17 10/31
my Multistage countercurrent extraction: minimum entering solvent flow rate. Liquid extraction equipment.
MSH pp. 783-789
T pp. 450-453
Lecture 17
Liquid extraction countercurrent examples (problems 3(a) and 5(a))
L18 11/02
my Introduction to mass transfer: where mass transfer is "hidden" in tray towers. Estimation of liquid- and gas-phase diffusion coefficients. Solute flux: definition
MSH pp. 527-540, 542-543 Lecture 18
Appendix 19
L19 11/07
djc Solute flux through 1D slab for cases of equimolar counterdiffusion and one-component mass transfer (A diffusing through non-diffusing B). Film theory and mass transfer coefficients. Two Film theory introduction
MSH pp. 547-548, 555-556 Lecture 19
L20 11/09
djc Two-film theory: interfacial mole fractions yi and xi, overall mass transfer coefficients Ky and Kx. Correlations for mass transfer coefficients: dimensionless groups (Sherwood number Sh, Stanton number St, Colburn j factor for mass transfer jM), correlation equations for various flow situations. Theory of Murphree tray efficiency.
MSH pp. 576-585 Lecture 20
Mass transfer two-film theory examples
Mass transfer correlations
Mass transfer theory of Murphree tray efficiency
L21 11/14
my Introduction to gas absorption with packed towers. Four alternate expressions for per-volume rate of mass transfer, integration of differential mass balance, height of transfer unit, number of transfer units.
MSH pp. 576-585 Lecture 21
Absorption packed towers introduction
Absorption packed towers example
Packed towers HTU (pp. 1-2, 5)
L22 11/16
my Mass transfer correlations for heights of a transfer unit (HTU's) Hy and Hx (equations and example). MSH pp. 576-585 Lecture 22
Packed towers HTU (pp. 3-4)
Packed towers mass transfer correlations
Table 18.1
Packed towers HTU example
L23 11/21
my Types of packing. Hydraulics of packed towers: loading and flooding, correlations for pressure drop and flooding velocity. Determination of tower diameter based on operation at a fraction (typically 50-60%) of the flooding velocity, or at an appropriate specified pressure drop.
MSH pp. 565-575 Lecture 23
Packed towers pressure drop and flooding example
L24 11/28
my Introduction to adsorption. Adsorption isotherms. Fixed beds: concentration profiles, mass transfer zone, break point and break-point time, breakthrough curve, length of unused bed.
MSH pp. 836-851 Lecture 24
Adsorption example
Exam 2 11/30
Covers Lectures 13-23, Homework 7-12
L25 12/05
my More detailed look at adsorption: fundamental mass transfer equations. Adsorbent regeneration.
MSH pp. 836-851 Lecture 25
Adsorption example 2
L26 12/07
djc Azeotropic Separations
Air Separation
Partial Condensers Revisited
Lecture 26
That's enough...

Learning outcomes: Click here for statement of learning outcomes

Composition of grade:
Homework 20%
2 Midterm Exams, 20% each 40%
Final Exam 40%

Assignment of grade: Final grades for all students will be determined by establishing an optimal correlation between total points earned over the course (computed according to the preceding table and scaled from 0 to 1000; essentially continuously distributed data) and grade points (4.00 for A, 3.67 for A-, 3.33 for B+, ..., 1.33 for D+, 1.00 for D; quantized results). The highest reasonably achievable score (considered "perfect") and the lowest passing score will be set according to the instructor's judgment and experience maintaining consistency with past offerings of the course, and will typically be ~900 (90%) and ~300 (30%) respectively. An effort will be made to position grade lines at gaps in the distribution of course totals. Click here to see a hypothetical example of this procedure.

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Grateful thanks to Johannes M. Nitsche for use of website and other course materials