1. Mass Transfer Equipment Design
Separation Process Principles, 4th Edition J.D. Seader, E.J. Henley, D.K. Roper, New York: Wiley, 2016.

2. Distillation Column

3. Distillation Column Design
Aspen: Material balance
Energy balance
Thermodynamic equilibrium
Bubble point / dew point summation
Specifications: Purity
Recovery

4. Aspen Equilibrium Stage Calculation1 D 2 F 3 B 4

5. Single Pass Sieve Tray
Active Area
Downcomer

6. Tray Efficiency
Steps: Run simulation to get physical properties and profiles
Calculate point efficiency (EOV) from Fair-Chan
Use tray mixing model and EOV to obtain Murphree efficiency (EMV)
Adjust EMV for tray entrainment to yield EMV,wet
Obtain overall efficiency Eo using EMV,wet and l

7. Point Efficiency Cyclohexane/n-Heptane
Tray Efficiency
Point Efficiency Cyclohexane/n-Heptane
Total Reflux
Dia, cm
Oldershaw
SRP
FRI

8. Fair-Chan Model
Chan, H., J.R. Fair,” Prediction of Point Efficiencies for Sieve Trays, 1. Binary Systems”,
Ind Eng. Chem. .Process Des. Dev., 23, (1984)
Chan, H., J.R. Fair, ,” Prediction of Point Efficiencies for Sieve Trays, 1. Multi-component Systems”,
Ind Eng. Chem. .Process Des. Dev., 23, (1984)

9. Fair-Chan Model

10. Fair-Chan Model (residence times)
Active (bubbling) area - A hL
Liquid Ua
Gas

11. Tray Mixing Enhancement
Barker, P.E. and Self, M.F, “The evaluation of liquid mixing effects on a sieve plate using unsteady and steady state tracer techniques”, Chem. Eng.Sci.,Vol. 17, pg (1962).

12. Murphree Tray Efficiency (EMV,wet)

13. Overall Efficiency (Eo)

14. Tray Diameter U C F foam factor for A D V M f where = - æ è ç ö ø ÷ ®
flood L ST HA h a T
vapor d = - æ è ç ö ø ÷ + é ë ê ù û ú r s p 1 2 20 10 5 06 4 / . : (
typical
value )
0.50

15. Pre-flooding Condition
Q Reboiler dP dP
Liquid Level
Liquid Level
Q Reboiler

16. Random Packing

17. Structured Packing

18. Design Equation
Area = S
HTUOG
NTUOG dZ

19. HTUOG Calculation
Two resistance theory - need individual coefficients and area from mass transfer model:
Onda, K., Takeuchi, H., Okumato, Y., “Mass Transfer Coefficients Between Gas
and Liquid Phases in Packed Columns,” Journal of Chemical Engineering of Japan,
1, 56 (1968).
Fair, J.R., Seibert, A.F., Behrens, M., Saraber, P.P., and Olujic, Z. “Structured Packing Performance-Experimental Evaluation of Two Predictive Models ”,Ind. Eng. Chem. Res. 39 (6), (2000).

20. Effective Area (aw)

21. NTUOG Calculation (Absorber Example)
Vout = 62 lbmol/hr
3.2 mol % NH3
Lin = 488 lbmol/hr 35
NTUOG
95 % NH3 removal 30 25 20 15 10
Vin = 100 lbmol/hr
40 mol % NH3 5
0.0
0.10
0.20
0.30
0.40 y

22. Packed Column HETP Behavior

23. Pressure Drop Behavior

24. Design Approach Renon SRK UniQUAC UniFAC RADFRAC Set Process
Specifications
Select Physical
Property Package
Run
Simulator
Determine
Final Dimensions
Apply
Efficiency Model
Evaluate
Hydraulics
Fair-Chan (Trays)
Onda (Random Packing)
Rocha-Bravo-Fair (Structured Packing)
AspenPlus

25. Reboilers

26. Reboilers Kettle Vertical Thermosiphon Top Tray Top Tray Heating
Medium
Heating
Medium
Bottoms Product
Bottoms Product
Kettle
Vertical Thermosiphon

27. Valve Tray Deck

28. Major Tray Damage

29. Fouling Resistant Design
Nutter V-Grid Trays’ strength, corrosion resistance and run lengths (fouling resistance) make them the petrochemical industry standard for corrosive or dirty services.

30. Distance from tower top
Gamma Scan Technology
Tower Scan
Distance from tower top
Tray Number

31. Liquid-Liquid Extraction Process

32. Typical Extractor Light Phase Dispersed Heavy Phase Dispersed
Out
Light Phase
Out
Heavy Phase In
Heavy Phase In
Light Phase In
Light Phase In
Heavy Phase
Out
Heavy Phase
Out
Light Phase Dispersed
Heavy Phase Dispersed

33. Sieve Tray Extraction
Photo of Sieve tray

34. Trayed Extractor Efficiency (Treybal Empirical Model)
Where: Ht = tray spacing (ft)
Ud = superficial dispersed
phase velocity
Uc = superficial continuous
s = interfacial tension (dyne/cm)

35. Packed Liquid-liquid Extraction
IMTP
Pall Rings
Structured

36. Membrane Technology

37. Membrane Nomenclature
Retentate (residue)
Feed
Permeate
Stage Cut = Permeate Flow / Feed Flow

38. Solution-Diffusion Model
Upstream pressure
pfeed
Downstream pressure
pperm JA
But before I go into how to improve the barrier properties, what is permeability and Barrer that I’ve been talking about? They can be best described by the solution-diffusion model which is a three step process for describing gas transport. First, the gas molecules sorb into the upstream surface of the film, followed by the diffusion of the gas through the film. The final step is the desorbing from the downstream surface.
The flow or flux of the gas through the film is defined as the permeability times the pressure difference divided by the film thickness. Permeability is a polymer property and is the product of the diffusion and solubility coefficients. The diffusion coefficient describes how fast the gas moves through the polymer and the solubility coefficient describes the attraction between the gas and polymer.
The unit for permeability is Barrer which contains the units for flux in volume per area per time, length, and pressure.
Component A
Component B
Wijmans, J.G., Baker, R.W. Journal of Membrane Science 107, 1-21, (1995)

39. Permeability – Selectivity Plot (glassy polymer)

40. Hollow Fiber Membranes

41. Membrane Module Designs
Retentate (residue)
Permeate
Tube side feed

42. CO2 Recovery - Amine Unit vs Membrane System

43. Hybrid System Composed of Both an Amine and
Membrane System for CO2 Processing
Sales Gas
Amine Contactor
Membrane Unit
Acid Gas
Feed
Acid Gas
Amine Stripper
Compressor

44. Adsorption Technology

45. Adsorbent Pore Structure
“A” Zeolite X
X = 3A (K+ form)
4A (Na+ form)
5A (Ca+ form)
Na12 (AlO2)12(SiO2)12 -H2O (Na form)

46. Adsorbent Cycles Contaminated Pure Air Air Stoiciometric Breakthrough
Mass Transfer Driven Breakthrough

47. Thermal Swing Regeneration
Mole sieve
drying bed
on process
Low Temp Separation
System
Tmin = -180 F
“Wet” natural gas
T = 450 F
Mole sieve
drying bed
on regen
Sales Gas

48. Pressure Swing Adsorption (PSA)
Langmuir Isotherm
Concentration on solid
Partial Pressure in Gas Phase