Wood to Wheels- Inquiry Lesson Plan
Lesson Introduction
 Title: Distillation Lab
- How does distillation improve the combustion capabilities of ethanol fermented
from glucose?

Subject/ target grade: 8th Grade Earth Science/8th Grade Inquiry Class

Duration: 2-57 minute class periods

Setting: science lab

-
Learning Objectives:
Students will be able to accurately set up the laboratory equipment to carry
out enzyme hydrolysis on biomass feedstock.
Students will be able to accurately measure liquid solutions using appropriate
tools (pipettes, graduated cylinders, etc.)
Students will be able to record data and make observations during the lab.
Students will be able to develop a conclusion based upon data and
observations from the lab.

Michigan Content Standards:
E1.1C Conduct scientific investigations using appropriate tools and techniques (e.g., selecting an
instrument that measures the desired quantity—length, volume, weight, time interval, temperature—
with the appropriate level of precision).
E1.1D Identify patterns in data and relate them to theoretical models.
 Lesson Overview: This is the third step in the conversion process of pretreated
biomass to ethanol. In this lesson students will be comparing the combustibility of the
hydrolyzate from the previous lab both before and after distillation. The distillation will
purify the ethanol solution making it burn better.
Lesson Core
 The Guiding Question: How does distillation improve the combustion
capabilities of ethanol fermented from glucose?
 Materials and Equipment Needed:
50-mL graduated cylinder
5 clamps
2 thermometers
Glass adaptor
boiling chips
50-mL flask
heating mantle or heat plate
2 ringstands
2 rubber tubing
condensing column
distillation column
watch glass to test for combustion
 Safety precautions:
Material :
Danger/Hazard:
Glass
Breakage-cuts
Heating mantle/heat plate
Burns
Electrical Equipment
Electrical burns
Hot water
Burns

hydrolyzate from fermentation lab
Precautions:
Take care
Use heat gloves
Keep away from water
Wear safety glasses/gloves
Advanced Preparation:
- The teacher should set up the distillation apparatus to assure that it is properly
assembled. The hydrolyzate has been saved from the previous “Ethanol
Fermentation From Glucose” lab.
- http://www.chem.ucalgary.ca/courses/351/laboratory/distillation.pdf

Background Information for Teachers:
-This is the third step in the conversion of wood biomass to ethanol process. In
the first lab, students started with pretreated aspen biomass and broke it down
with enzymatic hydrolysis to form glucose. The second lab started with a glucose
solution, and formed ethanol by the fermentation of this glucose solution by yeast.
Although ethanol was formed, it is not in a very pure form. In order to “purify”
this ethanol solution a distillation must be performed.
“Distillation is a widely used method for separating mixtures based on
differences in the conditions required to change the phase of components of the
mixture. To separate a mixture of liquids, the liquid can be heated to force
components, which have different boiling points, into the gas phase. The gas is
then condensed back into liquid form and collected.”
http://chemistry.about.com/cs/5/f/bldistillation.htm
Even after the distillation process, the ethanol will not be completely pure. A
ratio of 95% ethanol to 5% water is the “purest” to which the solution can be
distilled. This is, however, considerably more pure than the solution was when it
was first collected after the fermentation process in step two.
When decanting the hydrolyzate solution into the flask for distillation be
careful to pour off only the clearer top portion of the solution. During the
distillation process collect the first 2-4 mL, since this should be the purest ethanol.
After the distillation is complete, students will be able to combust or burn the
ethanol solution in a watch glass. There should be very little water left after the
ethanol burns off and the flame burns out. If the undistilled ethanol solution is
able to burn at all, there should be a much greater amount of water left on the
watch glass after the flame has burned out.
 Engage: Show the You Tube video about distillation from TutorVista.com
http://www.youtube.com/watch?v=xxNfJLMNS4E
-What is distillation?
-Briefly explain the steps in a distillation.
 Building on prior knowledge:
-Show the students two mason jars of water—one salt water and one fresh water.
-What process could make the salt water drinkable?
-How could you separate the salt from the water?
 Pre-teaching:
-Students will need to understand that different elements have different and
uniquely specific boiling/condensation points.
-Students will also need to understand that distillation makes the separation or
purification of mixtures possible.
-Students need to understand that elements can be identified by their density.
 Explore:
-Students will be given the lab procedure and will be expected to read it for
understanding as homework. The following lab period students will highlight the
important parts of each step, write out the steps in their own words in the blanks
and label the drawing of the apparatus.
-Students will answer the pre-lab questions.
-Students will watch and make notes as they observe the experiment.
 Explain:
-Students will make and record observations during the lab procedure.
-Each student lab group will discuss why this step was important to the
conversion process of the pretreated biomass to ethanol.
-The groups will then make a 1-2 minute presentation.
 Elaboration:
-How does the flame of the nondistilled solution compare with that of the
distilled?
-Why is there a difference?
-Was any liquid left in the watch glasses after combustion of the solutions?
-What was the liquid?
-Which solution had a greater amount of liquid? Explain why.
 Evaluate and Lesson Closure:
-What was the purpose of the distillation in this lab?
-What effect does distillation have on the combustion of this fuel?
-How did the distilled sample compare with the undistilled sample upon
combustion of each. Support your conclusion with evidence from your
experiment.
Lesson Extension

Assessment Options:
Formative: Student discussion of the importance of distillation in the conversion
process
Summative: Student lab report
 Additional Resources:
http://ochemapalooza.wikispaces.com/file/view/DIST_LAB_PICT.jpg/207196490/360x520/DIS
T_LAB_PICT.jpg
http://www.chem.ucalgary.ca/courses/351/laboratory/distillation.pdf
Name _____________________________________ Hour _______ Date ______
Student Hand-out #1
Lab Procedure
Step #
Given Directions
1.
Assemble the distillation kit, turn on
the tap water to run through the
condensing column
2.
3.
4.
Place the fermentation media (no
more than 300 mL in to the flask
with 5 boiling chips. Turn on the
power source of the heating plate
Turn on the power source of the
heating plate
Turn the heat plate on high until the
solution boils then turn down to
medium. Keep the fermentation
products boiling and monitor the
temperatures of both the boiling
liquid and condensing gas. Notice
that the vapors will condense in the
column with the packed glass beads
and liquid will run back down into
the flask. This is good. Vapor will
not reach the top of the column for
some minutes and you may need to
adjust the power upward or
downward to that eventually vapor
reaches to top and starts to slowly
condense in the water-jacket column
and drip slowly into the receiving
graduated cylinder. The temperature
of the condensing vapor should be
approximately 78-80 degrees
Celsius. Stop collecting the ethanol
product when the temperature
exceeds 80-82 degrees Celsius
(when temperature rises at the
thermometer measuring vapor
temperature, then more water and
less ethanol is in the vapor. The
temperature of the condensing gas
should be 78-80º C.
5.
6.
7.
8.
9.
10.
11.
12.
11.
Stop collecting the ethanol product
when the temperature exceeds 8082º C when temperature rises at the
thermometer measuring vapor
temperature, then more water and
less ethanol is in the vapor.
Collect 1 mL of distilled ethanol and
place in a pre-weighed sample jar.
Weigh the sample jar and distillate.
Determine the weight of the
distillate by subtracting the weight
of the empty jar from the total
weight of the jar and sample.
Compare the weight of the sample
with the Ethanol Density Chart.
The teacher will pour a 1 mL sample
of the distilled ethanol on a watch
glass, light it and have students
observe the flame (height, color,
length of time the flame burns,
moisture left behind after flame goes
out).
The teacher will pour a 1 mL sample
of the undistilled solution onto a
watch glass. Light the sample and
have students observe the flame
(height, color, length of time the
flame burns, moisture left behind
after flame goes out).
Turn off the power source of the
heating plate.
Allow the condensing column to
cool down to room temperature by
running water. Turn the water off
and dissmble the distillation lit.
Pour the remainder of the
fermentation media down to the
drain.
Name _______________________________ Hour _________ Date ________
Student Hand-out #2 Lab Report
Pre-lab Questions
1. What is the purpose of the distillation lab in the conversion process? ____________
________________________________________________________________________
2. Predict which sample (distilled and undistilled) will burn more efficiently. Explain.
________________________________________________________________________
________________________________________________________________________
3. How can you test the distillate to determine if it is ethanol? _____________________
________________________________________________________________________
Data Table:
Sample:
Observations during Combustion
Density
Additional Observations: ___________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
Conclusions: _____________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
Analysis Questions:
1. Which sample burned more efficiently (higher flame, color of flame)? ____________
_______________________________________________________________________
2. Explain your results. ____________________________________________________
________________________________________________________________________
3. Which sample’s density was closer to the density of ethanol? ____________________
________________________________________________________________________
4. What does this tell you about the sample? ___________________________________
________________________________________________________________________
5. Why isn’t the distilled sample’s density exactly the same as pure ethanol? _________
________________________________________________________________________
6. What errors could have occurred during this lab? _____________________________
_______________________________________________________________________
7. How could the lab be modified to eliminate these errors? _______________________
________________________________________________________________________
Lab Report Rubric:
Lab Report : Ethanol Distillation Lab
Teacher Name: Ms. Stoll
Student Name:
________________________________________
CATEGORY
Question/Purpose
4
The purpose of the
lab or the question
to be answered
during the lab is
clearly identified
and stated.
Conclusion
Conclusion
includes whether
the findings
supported the
hypothesis,
possible sources of
error, and what
was learned from
the experiment.
Experimental
errors, their
possible effects,
and ways to reduce
errors are
discussed.
Error Analysis
Data
Participation
Professional
looking and
accurate
representation of
the data in tables
and/or graphs.
Graphs and tables
are labeled and
titled.
Used time well in
lab and focused
attention on the
experiment.
3
The purpose of the
lab or the question
to be answered
during the lab is
identified, but is
stated in a
somewhat unclear
manner.
Conclusion
includes whether
the findings
supported the
hypothesis and
what was learned
from the
experiment.
2
The purpose of the
lab or the question
to be answered
during the lab is
partially identified,
and is stated in a
somewhat unclear
manner.
Conclusion
includes what was
learned from the
experiment.
1
The purpose of the
lab or the question
to be answered
during the lab is
erroneous or
irrelevant.
Experimental
errors and their
possible effects are
discussed.
Experimental
errors are
mentioned.
There is no
discussion of
errors.
Accurate
representation of
the data in tables
and/or graphs.
Graphs and tables
are labeled and
titled.
Accurate
representation of
the data in written
form, but no graphs
or tables are
presented.
Data are not shown
OR are inaccurate.
Used time pretty
well. Stayed
focused on the
experiment most of
the time.
Did the lab but did
not appear very
interested. Focus
was lost on several
occasions.
Participation was
minimal OR
student was hostile
about participating.
No conclusion was
included in the
report OR shows
little effort and
reflection.
DENSITY OF ETHANOL AND WATER MIXTURES (20°C)
Ethanol %
0
Density g/cc
0.998
Ethanol %
34
Density g/cc
0.950
Ethanol
68
Density g/cc
0.872
2
0.995
36
0.947
70
0.868
4
0.991
38
0.943
72
0.863
6
0.988
40
0.939
74
0.858
8
0.985
42
0.935
76
0.853
10
0.982
44
0.931
78
0.848
12
0.979
46
0.927
80
0.843
14
0.977
48
0.923
82
0.839
16
0.974
50
0.918
84
0.834
18
0.971
52
0.913
86
0.828
20
0.969
54
0.909
88
0.823
22
0.966
56
0.905
90
0.818
24
0.964
58
0.900
92
0.813
26
0.961
60
0.896
94
0.801
28
0.959
62
0.891
96
0.795
30
0.957
64
0.887
98
0.801
32
0.954
66
0.882
100
0.789
Teacher Key
1.
2.
3.
4.
5
6
7
8
Student Hand Out #4
Label the parts of the distillation apparatus shown above.