ChE 414
Chemical Engineering Laboratory II
Instructor
Dr. C. Niu
September, 2006
Website:
http://www.engr.usask.ca/classes/CHE/414/index.html
Text:
ChE 414.2 Laboratory Manual
(available online at course website)
Office hours: Thurs & Fri 10:00 a.m. – 11:00 a.m.
Rm: 1C129 Eng. Bld.
What Labs ?
• Surge Tank Data Acquisition and Process
Dynamics
• Fermentation: Kinetics of Yeast Growth
• Packed Column: Pressure Drop and
Flooding
• Filtration
• Centrifugal Pump
What Courses related?
Surge Tank:
CHE 413, 423
(process dynamics and control);
CHE 210, 320 (fluid mechanics)
Fermentation:
CHE 461 (biochemical engineering)
Packed column:
CHE 315, 421 (mass transfer)
Filtration:
CHE 315, 421 (mass transfer);
CHE 210, 320 (fluid mechanics)
Centrifugal Pump: CHE 210, 320 (fluid mechanics)
COURSE OBJECTIVES:
Develop skills in
- Equipment operation
- Data recording
- Analysis of the data using academic theory
- Technical report writing
in the selected typical Chem. Eng. processes
Marking
•
•
•
•
•
Lab performance: (4X2.5%)
Lab notebook: 10%
Technical letters: (2X10%)
Brief report: 25%
Formal report: 35%
Overall mark: 100%
No exam
Plagiarism is DEFINITELY NOT
acceptable!
– Copy other people’s report
– Citing without referencing the source
Plagiarism results in 0 mark for the report
Be aware of & Follow the new University of Saskatchewan
Academic Honesty/Dishonesty definitions, rules and procedures
www.usask.ca/honesty.
Due Date and Overdue Penalty
• Due date
– 2 weeks after the experiment date.
10 “free” late hand-in days for the whole course
Indicate on your report when use it.
• Penalty
– 10% of the full marks (100) per week
(2%/day) deducted from the late reports
– submissions will NOT be accepted after
Dec. 18th, 2006.
Requirements
• Lab performance
• Write-ups: technical writing
• Fundamentals of each lab
Lab performance
Be prepared for:
•
•
•
•
•
•
Objectives
Theory / knowledge
Design of experiment
Parameters to be measured
Apparatuses, procedures and principles
Find out: what to learn
Initiate the contact for the pre-lab help
with the demonstrators & the lab coordinator
Lab performance
During the experiments:
•
•
•
•
Follow the experimental procedures
Record observations in Lab Notebook
Test the validity of data and/or results
Pay attention to SAFETY issues
– personnel
– equipment
Write-ups / Reports
• Technical memo
• Brief report
• Formal report
• Lab notebook: during the experiments
Write-ups / Reports
One student is required to hand in
–
–
–
–
2 technical letters
1 brief report
1 formal report
1 lab notebook
Write-ups / Reports
No repetition in each group for
– formal report
– brief report
– technical letters
Write-ups / Reports
You
Your partner
Tech. letters
Labs A and B
Labs C and D
Brief report
Lab C
Lab A
Formal report
Lab D
Lab B
Lab notebook
Labs A,B,C,D
Labs A,B,C,D
In one group, you may label the 4 labs by A, B, C, and D in your own order.
Each member of the group should keep the same order.
Lab Notebook
No sheets of paper
Permanently bounded & recorded
• Briefly outline the title, apparatus,
experimental conditions and procedures
before labs
Suggest making table for recording data
• Record clearly all original observations
& simple calculations of data
• MUST be examined, dated and initialed by
the TAs before leaving the laboratory
Lab Notebook
Refer to ChE 333 class website for
RULES FOR LABORTORY NOTEBOOKS
Submit the lab notebook
at the end of the term for marking
Technical Memorandum
• Body of text: maximum two pages
• Introduction
- concise introduction of the system used
- a brief statement of the objectives of the experiment
- a general description of the procedure followed
• Results
- discussions and comparison of all required results with
values from literature
- equations used
- a brief table of results or major graphs attached to
support the conclusions.
• Conclusions and recommendations
• Sign your memo on the last page below the text
To:
From: (your name, group X)
Re: (Lab name)
Date: (of the preparation of the memo)
The text of memo is put here below the line.
Your group logo
(optional)
ChE 414 - TECHNICAL MEMORANDUM GRADE SHEET
Student: ______________________________________
Experiment: ______________________________________
Due Date: ___/___/___ Date Rec’d: ___/___/___ Late Penalty: ___ %
MAX
PRESENTATION
(FORMAT)
3
READABILITY
TECHNICAL
CONTENT
(RESULTS & CONCL.)
3
Total
10
4
MARK
Formal Technical Report
–
–
–
–
–
–
–
–
–
–
–
–
Title page and Table of Contents
Abstract
Table of contents, table of figures, table of tables
Introduction
Review of theory or literature
Experimental Section: apparatus and procedure
Results and Discussion
Conclusions
Recommendations
Nomenclature
Reference
Appendices
Formal Technical Report
Title page
• Course number
• Name (Your name and state the partner’s name)
• Lab title
• Prepared for (instructor’s name)
• Date lab done
• Date report due
Table of contents
Formal Technical Report
Abstract
• State briefly the purpose of the investigation
• Describe briefly how the results are obtained
• Give all required results in a concise and
quantitative format if possible.
• Use words, no tables, figures and equations
• Normally no more than 250 words.
Formal Technical Report
Introduction
• Include information on the subject of the
investigation and its importance in industry
• Cite the references;
• Describe clearly the objectives of the lab.
Formal Technical Report
Literature review or theory
• Provide sufficient theoretical background
to the particular experiments
• Develop the equations or models to correlate
your experimental data.
detailed derivation placed in Appendix
• Describe how to obtain the model parameters
and predict the particular system
• Cite the references
Formal Technical Report
Apparatus and Experimental Procedures
• Specify the main apparatuses used
make, model and use
• Describe the procedures
Highlight important experimental conditions
• Give the names of quality of the materials.
Make sure other people can repeat your work and obtain the same
results if they follow your description.
Formal Technical Report
Results and Discussions
• Present the significant experiment results
required in the Lab Manual in words and graphs.
• State the data treatment processes and the outcomes.
• Discuss the results of experiments and model simulations or
predictions.
• Compare your results with that in literatures if available.
• Logically discuss and lead to conclusions.
Attention
• Consistent format
• The unit for every parameters in the equations has to
be conformed.
• Figures or Tables in the body of text
– Titles of figures, axes, and tables
– Briefly state the experimental conditions
– Experimental data: represented by unique symbol for each
group of data in figures
– Modeling curves: different lines with legends
– Show model significance when fitting models
Cr uptake (mmol/g)
0.8
0.7
0.6
model predicting curve
relative dev.: 5.1%
model prediction when g =1
relative dev.: 11.5%
error bar: 95% confidence interval
w ithout NaCl
addition
0.5
0.4
0.1M NaCl
0.3
0.1M NaCl
0.2
pH 2.0
0.1
0
0
2
4
6
8
10
Equilibrium Cr concentration (mM)
Modeling the effect of IS on Cr uptakes
40±1 mg AWUS, 20±0.2 mL solution
Formal Technical Report
Conclusions and Recommendations
• Conclusions should be summarized following
the discussions.
• Lists your suggestions on how we can improve
the labs.
Formal Technical Report
Nomenclature
• Completely lists the symbols that appear
in your report, their definition and unit in a
professional and consistent format.
Refer to a published paper.
Formal Technical Report
Reference
• Completely lists every reference cited,
mentioned or used in the text of the report in a
professional and consistent format.
• Follows either the number order or the
alphabetical order.
Formal Technical Report
Reference format examples
In the text:
……Adams concluded that ……1. However, that conclusion may be suspicious because
……2
In the Reference section:
References
1. Adams, A. B. title of publication. ……
2. Cook, H. M., Author #2, ……
Ref: Industrial and Engineering Chemistry Research
or in the text:
It was concluded ( Adams, 2001) that ……. However, that conclusion may be suspicious
(Davis and Volesky, 2001) because ……(Niu, et. al., 2005)
References
Adams, A. B. year, title of publication, publisher, page (book)
Davis, T. and B. Volesky, year, title of paper, volume, issue, pages (paper)
Niu, C., M. Huang and M.Volesky, year ….
Ref: Canadian Journal of Chemical Engineering
Formal Technical Report
Appendices
• Raw data (neat with tables)
• Calculated data
• Sample calculation (using a set of data to
show the steps of calculations)
• Tables and Figures
Brief Technical Report
– Title page and Table of contents
– Summary
a brief introduction stating the nature and purpose of
the investigation
a brief explanation of the procedures and apparatuses
a summary of all the required results
– Results and Discussion: include major graphs or tables
– Conclusions
– Recommendations
– Appendices: only raw experimental data and a sample
calculation
Absence of abstract, introduction, theory/literature review,
materials and methods sections
A good report
• Careful measurements
• Correct calculations
• Understanding and use of the
theory or models
• Logical discussions
• Correct conclusions
Organized
Clarity
No grammar & typographical errors
• References
Fundamentals of labs
Filtration
A Standard Unit Operation:
physical separation of solid particles from liquid
or gas.
a porous medium: fluid to pass through
solid particles to be retained.
Filter cake
Filter medium
Slurry flow
Filtrate
a filtration plant for Water Treatment System
(http://www.carrolltown.pa.us/CBMA/)
Filtration Theory
• The driving force of filtration separation:
the pressure upstream of the filter
Filter cake
Filter medium
L
Slurry flow
Filtrate
Filtration
Objectives:
- Determine the relationship between the
upstream filter pressure and the flowrate
- Evaluate the applicability of the selected model
- Determine the model parameters
- Demonstrate the effect of filter aid (perlite) on
the filtration of CaCO3 slurry
- Develop skills on design of a filtration process
Theory:
The upstream filter pressure P (Pa)
(Bennett and Myers, 1982)
P=(K1V+K2)Q
if the cake is incompressible
For constant flowrate filtration Q,
V=Qt, then
P=K1Q2t+K2Q
Plot P~t, get K1 and K2
where
V: the volume of filtrate collected (m3)
Q: the flowrate of filtrate (m3/s);
t: time(s);
K1 and K2 : constants, highly dependent on the characteristics
of cake and filter medium, respectively
K1 and K2 values:
• Dependent on the characteristics
of cake, liquid and filter medium
• Determined by measuring
the upstream filter pressure P
as a function of time at specific Q
• Evaluate the resistances of the cake
and filter medium
• for filter design:
theoretically predict the required driving force
Fermentation: Kinetics of Yeast
Growth
• Involves in Yeast growth on substrate
glucose
• Major end products:
Ethanol: beer, wine, fuel
yeast biomass: high poundage product
500million pounds/year
Yeast needed for daily life
Fermentation: Kinetics of Yeast
Growth
Objectives:
- Demonstrate the yeast batch growth curve
- Determine the parameters of Monod equation.
- Calculate the yields of the products
- Design a fermentor for ethanol production
Fermentation theory
(J.M. Lee, 1992)
C6H12O6 → 2C2H5OH + 2CO2
•
•
•
•
Substrate: glucose
Microorganism: yeast
Low oxygen concentration
theoretical yielded ethanol: 51.1% by
weight
Typical growth curve for microorganism cells
Theory cont.
The production of the yeast biomass in a batch system in this lab is
 dX 
 X


 dt  growth
X is the cell concentrat ion g/L, t is time (h).
Then,
1 dX

X dt
 is the specific growth rate of the microorgan ism (1/hr)
Theory cont.
 is often modeled according to Monod equation :
m S

KS  S
where S is the substrate (glucose) concentrat ion (g/L)
 m is the maximun specific growth rate of biomass (h -1 );
K S is saturation constant (g/L), usually less than 1 g/L,
when S  K S ,    m .
Therefore,
X
ln
  mt
X0
experiment ally measure X versus t,  m is determined .
Theory cont.
- biomass yield YXS : the ratio of the biomass produced
to the amount of substrate consumed
dX
dS
 YXS
dt
dt
- ethanol yield YPS : the ratio of the product produced
to the amount of substrate consumed
dP
dS
 YPS
dt
dt
P is the end product enthanol concentrat ion (g/L).
Theory cont.
When the yield is constant,the above equations becomes :
(X  X )
0
Y

XS
(S  S )
0
P
Y

PS ( S  S )
0
S and X are the inital concentration of substrateand biomass, respectively.
0
0
Experiment ally measure X , P versus S , Y
and Y are determined .
XS
PS
Surge Tank Data Acquisition and
Process Dynamics
(http://www.ih.navy.mil/cbf/images/SurgeTank)
• Common problem: propagation of disturbances between processes
• Solution : surge tank
– Damp out the changes of the inlet flowrate
– Deliver a steadier outlet flowrate to the downstream process
Surge Tank Data Acquisition and
Process Dynamics
Objectives:
- Evaluate the applicability of selected models
relating the outlet flowrate versus head
- Derive and test mathematical models for the
transient behavior of a liquid surge tank
- Record the data with automatic acquisition
system - LabVIEW
Surge Tank
• Data acquisition and control: a computer
with LABVIEW Software package
Automation, more precise.
• Collect data: water flow rate and water
head in the tank
Familiar with the software
Surge Tank
A
h
qout
qin
h: the height of the liquid level in the surge tank (head) (ft);
qin: the inlet water flowrate (ft3/s);
qout: the outlet water flowrate (ft3/s)
A: the cross sectional area (ft2).
Surge Tank Theory
Mass balance at transient period:
dh
 (qin  qout ) / A
dt
t: time (s),
where the density of the liquid is constant
Theory cont.
• Flow exit a surge tank through a valve follows:
(D. R. Coughanowr and L. B. Koppel, 1965, p.60)
qout ~ h½
e. g. qout = C1h½ (qout is linearly proportional to h½ )
qout = Co+C1h½
or
qout = Co+C1h½ + C2 (h½)2 + C3 (h½)3 +…+ Cn (h½)n
(n> 1, qout is non-linearly proportional to h½ )
• Constant Ci is determined by fitting the above equations,
respectively, to the experimental data (qout ~ h1/2) at
steady state, where qout = qin. (Microsoft Excel)
• Compare the fitting results of different models
Theory cont.
Substituting the qout in the mass balance equation yields
non-linear differential equation:
dh
 (qin  qout ) / A
dt
Solutions:
-Analytical:
closed-form, a general picture of the process behavior
independently of the particular values of the input variables
process design and control limited to linear processes
-Numerical:
dependent on the values of the input variables.
Analytical Solution
• Linearize the non-linear differential equation by Taylor
series expansion of the non linear term around a point
(e.q. steady state) (Stephanopoulos, G., 1985, p.116-121)
• Convert the differential equation to algebraic equation by
Laplace transforming
(D. R. Coughanowr and L. B. Koppel, 1965, p.13-41, 67-70)
• Invert the transform to get h as a function of time
(D. R. Coughanowr and L. B. Koppel, 1965, p.13-41)
Use this equation to describe the experimental data at unsteady
state
Analytical Solution
• For example, qout = C1h½ ,
• Linearize the non-linear differential equation:
(Stephanopoulos, G., 1985, p.116-121)
dh
 (qin  C1h1/ 2 ) / A
dt
Take the first order of Taylor series expansion of the term qout
around a point (e.q. steady state):
qout qout, s q ' out, s (h  hs )
q out  q out, s 
1
R  2hs 2 C1
1
(h  hs )
R
Linear form
Subscript s represents the steady state.
Analytical Solution
Substitute the first order Taylor series expansion of qout in
the differential equation,
h  hs
dh
 (qin  qout, s 
)/ A
dt
R
at steady state, q in, s q out, s
h  hs
dh
 ( qin  qin, s 
)/ A
dt
R
use deviation varibles,
H  h  hs , Qin  qin  qin, s ,
obtain
dH
H
 (Qin 
)/ A
dt
R
Analytical Solution
Convert the differential equation to algebraic
equation by Laplace transforming
(D. R. Coughanowr and L. B. Koppel, 1965, p.13-41, 67-70)
H ( s)
R

s  1
Qin ( s )
  RA
H (s)
is Laplace transform of derivation variable h-hs
Qin (s)
is Laplace transform of derivation variable qin-qin,s
represents the Laplace function.
s
Analytical Solution
When the inlet flowrate is increased or decreased
around certain steady state:
0

Qin  qin  qin, s  
M

t<0
t≥0
Take the transform of Qin
 0


Qin ( s )  
M

s

t<0
t≥0
Input the time conditions,
H (s)

0


= 
 RM

s (s  1)

t<0
t≥0
Invert the transform,
(D. R. Coughanowr and L. B. Koppel, 1965, p.13-41)
t
H  h  hs  RM (1  e  )
t
h  hs  RM (1  e  )
t≥0
Numerical Solution
dh
 (qin  qout ) / A  f (h)
dt
Where qout = Co+C1h½ + C2 (h½)2 + C3 (h½)3 +…+ Cn (h½)n
n = 1, …n
Eularian theory: (Rice, RG, 1995)
hn  hn1  t * f (hn1)
Compare the analytical model solution with the numerical solution.
Use two equations of qout ~h1/2 at n=1 & n>1 for all cases in this lab.
Packed Column: Pressure Drop and
Flooding
(http://www.syndel.com/images/powell_apr02-2.jpg)
Packed column: widely-used industrial equipment for mass
transfer processes: distillation, adsorption and extraction
Packed Column
Gas-liquid counter-current flow in packed
column:
G out
• Liquid: downwards flow
L in
• Gas: upwards flow
• Flooding conditions
G in
L out
Design Criteria
• pressure drop: caused by the resistance of
packing to fluid flow.
• The flood velocity: an important
parameter for gas-liquid packed column
design
Packed Column: Pressure Drop and
Flooding
Objectives:
- Determine the relationship of pressure
drop and the flowrate in a packed column
- Evaluate the applicability of Ergun
equation for a single gas flow system
- To determine the pressure drop
and flooding condition in a gas-liquid
system
Packed Column
Pressure drop for a single flow through packed bed-Ergun equation
3
P g c d p  g 150(1   )

 1.75
2
z (1   )G
Re
where
(Treybal, R.E., 1980, P.200.)
P is pressure in lb/ft 2 ;
 is porosity  volume of void/tota l bed volume;
g c  32.174lb m  ft/s 2  lb f  4.17  108 lb m  ft/h 2  lb f ;
d p is diameter or effective diameter of packing in ft;
Re is the Renold number;
z is length down the packed bed in ft;
G is superficia l mass velocity in lb m /ft 2  h.
ρ g is gas density in lb m /ft 3 ;
Packed Column Theory
Flooding conditions
for a gas-liquid flow through packed bed
(B. Miline, 1994)
p
bY
 aYe
Z
Y: a function of gas flowrate
a, b, e: constants for a specific system.
Symbol definition! Units!
Packed Column
• Models are empirical equations.
• Different models fit differential systems.
• Evaluate the applicability of the selected
model for the experiment system
Centrifugal Pump
• The most common type of fluid mover in the
chemical industry
• To convert energy of a prime mover (an electric
motor or turbine) first into velocity or kinetic
energy and then into pressure energy of a fluid
that is being pumped.
http://www.pumpworld.com/centrif1.htm
Centrifugal Pump
- To determine the characteristics of a
centrifugal pump including total head, brake
horse power, efficiency and net positive
suction power (NPSH) versus flowrate.
- To determine the size of a geometrically
similar pump needed to pump against a
total head of 100 feet of water at peak
efficiency
Reference Books
C.O. Bennett & J.E. Myers, "Momentum, Heat, and Mass
Transfer", 3rd Edition, McGraw-Hill, 1982.
D.R. Coughanowr & L.B. Koppel, "Process Systems
Analysis and Control", McGraw-Hill, 1965.
G. Stephanopoulos, “Chemical Process Control –
Introduction to Theory Practice”, Prentice Hall, 1984.
J.M. Lee, "Biochemical Engineering", Prentice Hall, 1992,
pp 100-152.
R.E. Treybal, "Mass-Transfer Operations", McGraw-Hill,
1980.
R.S. Blicq. "Technically-Write!", Prentice Hall, 2nd Edition,
1981.
R.G. Rice, “Applied Mathematics and modeling for
chemical engineers”, John Wiley and Sons, Inc. 1995,
pp231.
Other References
1.
2.
3.
4.
5.
6.
7.
James R. Welty, Charles E. Wicks, Robert E. Wilson, and Gregory
Rorrer, Fundamentals of Momentum, Heat and Mass Transfer. 4th
Edition, John Wiley and Sons, Inc. 2001
Jaime Benitez, Principles and Modern Applications of Mass
Transfer Operations. John Wiley and Sons, Inc. 2002
Donald R. Coughanowr, Process Systems Analysis and Control.
McGraw-Hill, Inc. 1991
Hans, F. Ebel, Claus Bliefert, and William E. Russey, The Art of
Scientific Writing. 2nd Edition, John Wiley and Sons, Inc. 2004
Christie J. Geankoplis, Transport Processes and Separation
Process Principles. 4th Edition, Prentise-Hall, Inc. 2003
Milne, W.E., Numerical Solution of Differential Equations, Wiley,
NY, 1953.
Quinney, D., Introduction to the numerical solution of differential
equations, research Studies Press, NY, 1987.
Have your own references to make your report strong!
Important dates
• 19 Sep: Last day to change first term
registration.
• 9 Oct: Thanksgiving (University Closed),
• 4 Dec: Last day of classes.
• 18 Dec: Last day to hand in laboratory
reports and laboratory notebooks for
marking
Summary
• Academic theory understanding
• Lab performance
• WRITEUPS
Successful!