Overall Review CHE 1008

1
Overall ReviewCHE 1008

• Chapters 1-5, 6.4, 7, 9, 11, 12, 15

2
Exam Details

• Date, Time, Place Tuesday, 20 April, 2-4 PM,
  FMLC
• Closed book, closed notes, I will provide an
  equation summary sheet
• Bring a calculator, ruler, pencils
• Test will include
• Multiple choice
• Short answer
• Calculations (by calculator, not Mathcad or
  Aspen)
• Test will be comprehensive

3
What Could Be On The Exam?

• Anything in the reading assignments
• Hint Review your reading. If you have marked
  your book carefully this will not be very
  difficult to do
• Anything in the homework---you will not have to
  do Mathcad---you will have to know how to solve
  the problems
• Hint Review all the homework and homework keys,
  know how to solve every problem
• Anything covered in class lectures
• Hint Review the lecture notes, make sure you
  understand the concepts
• Anything covered in recitation

4
What Will Not Be On The Exam?

• Aspen or Mathcad problems
• Dialysis problems
• Problems that required very detailed calculations
• Multi-part problems (like the problems on the
  previous exams)

5
Concepts Covered

• Chapter 2
• Phase equilibria
• Plotting Txy xy VLE data
• Reading labeling Txy, xy, Ponchon-Savarit
  diagrams
• Lever arm rule
• Define use K values
• Know how to find dew-points bubble-points
  (algorithms)

6
Concepts Covered

• Chapter 3
• Describe the flash distillation process
• Plot the operating line for binary flash on an xy
  diagram
• Know how to solve sequential and simultaneous
  flash problems
• Algorithms
• Rachford-Rice energy balances

7
Concepts Covered

• Chapter 4
• Explain how distillation works
• Sketch and label the parts of a distillation
  column and know how the parts work
• Solve external mass and energy balances

8
Concepts Covered

• Chapter 5
• Write solve mass and energy balances for each
  stage in a column
• Know when CMO is valid and why it is typically
  assumed
• Use the operating equations for CMO distillation
• Calculate feed quality
• Find the number of stages and optimal feed stage
  using the McCabe-Thiele method

9
Concepts Covered

• Chapter 6
• Know what total reflux is and why it is useful
• Know what minimum reflux is and why it is useful
• Chapter 7
• Know why multicomponent distillation is
  trial-and-error
• Use assumptions to solve external mass and energy
  balances for multicomponent distillation

10
Concepts Covered

• Chapter 9
• Know when the Fenske equation can be used
• Use the Fenske equation to compute Nmin, NF,min,
  and splits of non-key components
• Use the Underwood equations
• Use the Gilliand correlation

11
Concepts Covered

• Chapter 11
• Describe how simple batch distillation works
• Explain how multistage batch distillation works
• List the differences between batch and continuous
  distillation
• List advantages and disadvantages of each
• Solve simple batch distillation problems
• Describe how to solve multistage batch
  distillation problems

12
Concepts Covered

• Chapter 12
• Describe different types of trays, listing
  advantages and disadvantages for each
• Discuss the concept of efficiency
• Compute the diameter of sieve and value trays
• Chapter 15
• Compare and contrast adsorption and stripping
  operations
• Compare and contrast adsorption/stripping with
  distillation
• Describe how to use the McCabe-Thiele method for
  adsorption and stripping
• Discuss calculation of the operating lines for
  adsorption/stripping

13
Sample Questions

• List the assumptions of constant molal overflow
• Given a value of a, and fractional recovery,
  compute Nmin
• Compute the top and bottom operating lines (given
  sufficient information)
• Identify features of Txy and xy phase diagrams
• Use a Ponchon-Savarit diagram to find the
  enthalpy and composition of the outlet streams
  from a flash drum
• Draw operating lines and stages on a xy diagram
  to estimate the number of trays in a distillation
  column using McCabe-Thiele analysis
• You can assume that the mass flow rates of the
  liquid and vapor streams are constant in an
  absorber problem when
• (a) The solute concentrations are lt 10
• (b) Henrys law is valid
• (c) The solute concentrations are 1 or less
• (d) Both (b) and (c)