From Fryer to Fuel
By Troy Criss, USD #259 Wichita School District Northeast Magnet High School, and Jo
McCormick, USD #500 Kansas City, Kansas School District Washington High School
Funded by the NSF Research Experiences for Teachers: Shaping Inquiry from Feedstockto-Tailpipe program at the University of Kansas, summer 2010
https://www.cebc.ku.edu/education/RET-2010.shtml
For more information, contact: Claudia Bode, bode@ku.edu, 785-864-1647
Learning Experience Description:
Students will explore the production of biodiesel. Using molecular models, students will
complete a model of the reaction of triglycerides with methanol. Students will then
prepare biodiesel from used fryer oil or from vegetable oil. The oil will be titrated with
potassium hydroxide and the results of the titration will be used to determine the amount
of potassium hydroxide catalyst needed to make the biodiesel from oil and methanol.
Students will then make the biodiesel from the used oil or unused oil, wash the biodiesel
and do some tests comparing the properties of vegetable oil, biodiesel, and diesel oil.
Bioscience Connection:
Biotechnology applies science to living things to solve a problem. Depletion of available
fossil fuels is a problem and scientists are using renewable plant sources to make
biofuels. Common biofuels are ethanol and biodiesel. Ethanol is produced from plant
sugars, often corn sugars. Current research in ethanol production is focusing on using
alternative sources for ethanol production including cellulose from sources such as
switchgrass. Biodiesel is produced from vegetable oils such as soy oil, canola oil or used
frying oil from restaurants. Current research in biodiesel production is focusing on oils
produced from algae and new catalysts.
Background Information:
The United States has become increasingly dependent upon crude oil that is becoming
harder and harder to find. The current gulf oil disaster is an example of the extremes
needed to locate and extract crude oil. Biodiesel is a clean, biodegradable and renewable
alternative to the use of diesel fuel. Natural plant oils are reacted with an alcohol and a
catalyst to produce biodiesel in a process called transesterification.
Producing biodiesel requires three major components:
1. Oil: The oil can come from a plant or animal. It can be straight (unused) oil or it
can be used (waste) cooking oil. Oils are made up of three long chains of fatty
acids connected to a glycerin backbone called a triglyceride
2. Alcohol: Many different types of alcohols can be used to make biodiesel. The
alcohol used in this experiment is methanol. Methanol is both inexpensive and
readily available. When methanol is used, the fatty acids in the oils are converted
to methyl esters that are referred to as fatty acid methyl esters (FAME) or
biodiesel. Different alcohols will produce different types of biodiesels. Ethanol
converts the fatty acids to ethyl esters. The reaction with ethanol is more difficult.
3. Catalyst: A strong base is needed to start the reaction. The bases generally used
are sodium hydroxide (NaOH) and potassium hydroxide (KOH). This experiment
will be using KOH.
The reaction to produce biodiesel from vegetable oils is shown below. The triglycerides
react with methanol in a process called transesterification. The fatty acids are broken off
the glycerin backbone and converted to esters. The glycerin backbone becomes glycerol,
a heavy, dense, sweet-tasting, viscous liquid that will settle to the bottom of the container
below the biodiesel. The fatty acid methyl esters (FAME) make up the biodiesel and can
have various carbon lengths and be saturated or unsaturated. Saturated FAME have all
single bonds between the carbons. Unsaturated FAME have at least one double bond in
the carbon chain of the fatty acid. A schematic showing the process flow for the
production of biodiesel is shown below.
Figure 1 : The biodiesel reaction.
http://upload.wikimedia.org/wikipedia/commons/7/72/Generic_Biodiesel_Reaction1.gif
Figure 2: Steps in the producing biodiesel.
2
Biodiesel generally does not completely replace diesel, instead it is mixed with diesel in
different concentrations. The concentration or percentage is called the B Factor, which
stands for the ratio of biodiesel to diesel. B5 is a mixture of 5% biodiesel to 95% diesel.
B20 is a mixture of 20% biodiesel to 80% diesel and B100 would be pure biodiesel.
Additional background information is available in the following links
 http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/biodiesel.htm
 http://communitybiofuels.com/references/Teacher%20Handout.doc.
 http://www.cleanfuelsohio.org/learnbiodiesel5.php
 http://auto.howstuffworks.com/diesel.htm
Grade Level:
High school chemistry students
Duration of Learning Experience:
3-5 hours
Pre-Visit Classroom Information:
1. Read the ChemMatters article “Do You Want Biodiesel With That?”
(ChemMatters, April 2005, p 7-9. ) Complete the reading strategies activity
suggested in the teacher’s guide. Both the article and the teacher’s guide can
be found at:
http://portal.acs.org:80/preview/fileFetch/C/WPCP_010910/pdf/WPCP_01091
0.pdf
Post-Visit Classroom Information:
1. Use the problems in Appendix 2 to integrate biodiesel problems throughout
the year.
2. Access the following link for ideas for labs and activities to integrate biodiesel
throughout the year.
 http://www.teachbiofuels.org/
 http://www.teachersdomain.org/resource/psu06-e21.sci.biodiesel/
 http://www.biodiesel.org/pdf_files/Biodiesel_Curriculum_Schools.pdf
 http://www.ecologycenter.org/tfs/pdf/2003summer/Biodiesel.pdf
 http://
wupcenter.mtu.edu/education/energy_education/lesson_plans.html
 www.hannibalcsd.org/teacherwebs/dbattles/itc/achem/biodiesel%20lab
.doc
 www.toshiba.com/taf/common/docs/Biofuels.pdf
 www.fishersci.com/wps/downloads/.../green_BiodieselModule.pdf
Concept / Topic:
Preparation and testing of biodiesel fuels produced from used frying oils or vegetable
oils.
3
Vocabulary:
 alcohol
 alternative energy
 aromatic compound
 biodiesel
 Bxx
 catalyst
 cetane number
 cloud point (CP)
 cold filter plugging point (CFPP)
 combustion
 density
 energy balance
 esters
 fatty acid methyl esters (FAME)
 fatty acids
 feedstock
 fuel
















gel point
glycerin (glycerol)
hydrocarbon
lubricity
particulate matter
phase
pour point
renewable energy
saturated fatty acids
soap
straight vegetable oil (SVO)
transesterification
triglycerides
unsaturated fatty acids
vegetable oil
viscosity
Content Standards, Benchmarks, and Indicators Addressed:
STANDARD 1: Science as Inquiry
SCIENCE AS INQUIRY– The student will develop the abilities necessary to do
scientific inquiry and develop an understanding of scientific inquiry.
Benchmark 1: The student will demonstrate the abilities necessary to do scientific
inquiry.
The student…
Indicators:
1. actively engages in asking and evaluating research questions.
2. ▲ actively engages in investigations, including developing questions, gathering and
analyzing data, and designing and conducting research
3. ▲ actively engages in using technological tools and mathematics in their own
scientific investigations.
4. actively engages in conducting an inquiry, formulating and revising his or her
scientific explanations and models (physical, conceptual, or mathematical) using logic
and evidence, and recognizing that potential alternative explanations and models
should be considered.
5. actively engages in communicating and defending the design, results, and conclusion
of his/her investigation.
STANDARD 2A: CHEMISTRY
CHEMISTRY – The student will develop an understanding of the structure of atoms,
4
compounds, chemical reactions, and the interactions of energy and matter.
Benchmark 2: The students will understand the states and properties of matter.
The student …
Indicators
1. ▲ understands chemists use kinetic and potential energy to explain the physical and
chemical properties of matter on earth that may exist in any of these three states:
solids, liquids, and gases.
3. ▲ understands chemical bonds result when valence electrons are transferred or shared
between atoms. Breaking a chemical bond requires energy. Formation of a chemical
bond releases energy. Ionic compounds result from atoms transferring electrons.
Molecular compounds result from atoms sharing electrons. For example, carbon
atoms can bond to each other in chains, rings, and branching networks. Branched
network and metallic solids also result from bonding .
Benchmark 3: The student will gain a basic concept of chemical reactions.
The student …
Indicators
1. ▲ understands a chemical reaction occurs when one or more substances (reactants)
react to form a different chemical substance(s) (products). There are different types of
chemical reactions all of which demonstrate the Law of Conservation of Matter and
Energy.
2. understands how to perform mathematical calculations regarding the Law of
Conservation of Matter, i.e., through stoichiometric relationships.
3. understands the differences and reactions between acids, bases, and salts. Perform
calculations to determine the concentration of ions in solutions.
STANDARD 3: LIFE SCIENCE
LIFE SCIENCE – The student will develop an understanding of the cell, molecular basis
of heredity, biological evolution, interdependence of organisms, matter, energy, and
organization in living systems, and the behavior of organisms.
Benchmark 4: The student will understand the interdependence of organisms and their
interaction with the physical environment.
The student...
Indicators
1. ▲ understands atoms and molecules on the earth cycle among the living and nonliving
components of the biosphere.
5. understands human beings live within and impact ecosystems.
STANDARD 6: SCIENCE IN PERSONAL AND ENVIRONMENTAL PERSPECTIVES
5
SCIENCE IN PERSONAL AND ENVIRONMENTAL PERSPECTIVES – The student
will develop an understanding of personal and community health, population growth,
natural resources, environmental quality, natural and human induced hazards, and science
and technology in local, national, and global settings.
Benchmark 1: The student will develop an understanding of the overall functioning of
human systems and their interaction with the environment in order to understand specific
mechanisms and processes related to health issues.
The student …
Indicators
1. understands some chemical and physical hazards and accidents can be avoided through
safety education
Benchmark 3: The student will understand that human populations use natural resources
and influence environmental quality.
The student …
Indicators
1. ▲ understands natural resources from the lithosphere and ecosystems are required to
sustain human populations.
2. understands earth does not have infinite resources.
Benchmark 5: The student will develop an understanding of the relationship between
science, technology, and society.
The student …
Indicators
1. understands progress in science and technology can be affected by social issues and
challenges. Science and technology indicate what can happen, not what should
happen.
Technology Standards Addressed:
STANDARD 5: SCIENCE AND TECHNOLOGY
SCIENCE AND TECHNOLOGY – The student will develop understandings about the
relationship between science and technology.
Benchmark 1: The student will develop an understanding that technology is applied
science.
The student …
Indicators
1. ▲ understands technology is the application of scientific knowledge for functional
purposes.
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3. understands science advances new technologies. New technologies open new areas for
scientific inquiry.
Learning Experience Objectives:
After completing these activities the student will be able to:
1. Explain why biodiesel is an important alternative to petroleum diesel.
2. Describe the process of transesterification utilizing chemical formulas.
3. Explain how biodiesel is derived from three reactants: triglyceride (oil),
alcohol and a catalyst.
4. Explain the process of biodiesel production from unused cooking oils.
5. Explain the process of biodiesel production from waste vegetable oils.
6. Conduct chemical analyses necessary to determine oil quality.
7. Identify and test different fuel properties.
8. Determine the density of a liquid.
9. Compare the viscosity of biodiesel to unused cooking oil and to diesel.
10. Compare how the solvent nature of biodiesel is different from that of diesel
and unused cooking oil.
Required Materials:
Provide a bulleted list of items required to teach this learning experience. Include
necessary media, science, or technology equipment, and other supplies. The location of
materials as well as ordering information should be included as well,
 Computer with windows media player
 Computers with internet access
To Titrate the Oil
 Used cooking oil (available from local restaurants-free)
 Soy, canola or other cooking oil (available from grocery store
- $6/gallon)
 Isopropanol (available as Iso-Heet ($2/350 mL) from
automotive supply store or from science supply such as Flinn
Scientific)






Potassium hydroxide ($9/500 g lab grade)
(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=20656)
Diesel fuel (purchased from gas station) ($3/gallon)
Storage container for diesel fuel ($7 at Walmart)
0.5% Phenophthalein indicator ($5/100 mL)
(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=20703)
Eyedropper for phenolphthalein if not included in bottle
Titration buret ($50)
7




(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=19306)
Buret clamp ($14)
(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=16911)
Ring Stand ($15)
(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=16920)
250 mL beaker ($3)
(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=19288)
5 mL syringe (available free from most pharmacies)
To prepare and separate biodiesel
 Used cooking oil (available from local restaurants-free)
 Soy, canola or other cooking oil (available from grocery store - $6/gallon)
 Potassium hydroxide ($9/500 g lab grade)
(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=20656)
 Methanol (available as Heet ($2/350 mL) from automotive supply store or from
science supply such as Flinn Scientific)
 Pint mason jar (Walmart $7/dozen) or 500 mL separatory funnels ($60 each)
(http://www.indigo.com/glass/separatory-filter-funnels.html)
 If separatory funnels are not available, 16 oz HDPE bottles
with pull caps can be used to separate the biodiesel from the
glycerol ($12 for 12 bottles) (http://www.sksbottle.com/340c/fin41g.html)
 Hot plate ($165)



(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=21765)
Balance
250 mL beaker
100 mL graduated cylinder
Determining the pH of Washed and Unwashed Biodiesel
 Wide Range pH paper ($16/roll)
(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=14256)
Comparing the solvent properties of diesel oil, biodiesel oil and vegetable oil.
 Diesel fuel (purchased from gas station) ($3/gallon)
 Storage container for diesel fuel ($7 at Walmart)
 Soy, canola or other cooking oil (available from grocery store - $6/gallon)
 Biodiesel sample produced earlier in lab
 12 mL glass vials with caps (test tubes with cork stoppers may also be used)
(available from SKS Bottle-$62/72 vials http://www.sksbottle.com/340c/fin12a.html)
 0.5 cm x 4 cm strips cut from a Styrofoam cup
Comparative viscosity of vegetable oil, diesel oil and biodiesel
 Diesel fuel (purchased from gas station) ($3/gallon)
8





Storage container for diesel fuel ($7 at Walmart)
Soy, canola or other cooking oil (available from grocery store - $6/gallon)
Biodiesel sample produced earlier in lab
Plastic clipboard (available from Walmart - $3)
Eye droppers or disposable pipettes ($40/pkg of 400
(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=18845)
Observing Biodiesel at Different Temperatures
 Diesel fuel (purchased from gas station) ($3/gallon)
 Storage container for diesel fuel ($7 at Walmart)
 Soy, canola or other cooking oil (available from grocery store - $6/gallon)
 test tubes ($3.20 each)
(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=19407)
 ice bath with salt
 freezer (optional)
 Thermometers ($10 each)
(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=17278)
Lab Safety:
The production of biodiesel can be a very hazardous process. The chemicals
needed are corrosive, poisonous and explosive.
Methanol is very explosive and burns with a nearly invisible flame. Methanol
vapor is denser than air so it will sink to the floor and not be noticed until it explodes.
The vapors from methanol can cause damage to the central nervous system. Methanol is
also poisonous and can cause blindness or death if ingested. It can be absorbed through
the skin and has been known to cause birth defects.
Potassium hydroxide is very corrosive. It can cause severe burns and can be fatal
if ingested. The dust from KOH can cause severe burns to the lungs if inhaled.
Potassium hydroxide will cause blindness if it comes into contact with the eyes.
Methanol and potassium hydroxide react to form methoxide. Methoxide is very
hazardous and will destroy tissues causing severe burns. The methoxide should be
prepared and used immediately. Mixing of the methanol and KOH is best done in a fume
hood. Having access to running water to rinse off any spill is also recommended. Do not
breathe any of the fumes.
Safety equipment must be worn at all times in the lab.
1. Goggles
2. Chemical proof gloves
3. Lab coats or aprons
4. A dust mask is recommended when handling large quantities of KOH.
MSDS Potassium Hydroxide - http://www.jtbaker.com/msds/englishhtml/p5884.htm
9
MSDS Methanol - http://www.midi-inc.com/pdf/MSDS_Methanol.pdf
MSDS Methoxide - http://www.midiinc.com/pdf/MSDS_Reagent_A_Potassium_Methoxide_Methanol.pdf
MSDS Biodiesel - http://www.biodiesel.org/pdf_files/fuelfactsheets/MSDS.pdf
Although the MSDS for biodiesel states biodiesel is not harmful to humans, remember
that biodiesel made in the lab may have residue chemicals that are very harmful.
Technology Connection:
Students will explore the chemistry of oils using the internet.
Anticipatory Set:
Why study chemistry? Why will the students in your class spend hours of their
time memorizing the chemistry facts that you ask them to learn? For your students who
want to go on to college, avoiding getting bad grades will be reason enough. But do the
majority of your students really want to go to college where the knowledge of chemistry
will be of help to them or is your class just another science credit that they will need in
order to graduate high school?
Make your chemistry class relevant to your students. Have your students conduct
labs and activities that they can see have connections to their own lives but also meet the
requirements of the state science standards.
Why study biodiesel?
The diesel engine was invented in the early 1900’s and used peanut oil for fuel.
Currently diesel fuel comes from crude oil. Crude oil is a fossil fuel and therefore in
limited supply. The U.S and other countries are looking deeper into the ocean and farther
into the northern wilderness to find oil. Tragic accidents have been occurring due to these
searches. The Exxon Valdez dumped thousands of barrels of oil into the waters of Alaska
causing a tremendous natural disaster. Currently BP (British Petroleum) is trying to stop
and clean up an oil spill that is threatening wildlife, destroying fisheries, and damaging
the economy in the Gulf of Mexico.
What are the alternatives to using crude oil? The production of biofuels gives our
society a chance to break away from our dependency on crude oil. Biofuel production,
especially biodiesel production, can be done using renewable resources. It is better for the
environment and better for us.
Anticipatory Set for Students
1. Why are alternatives to gasoline and diesel oil needed?
a. I think, We think Activity
b. Share the question with the class and ask each student to list possible
reasons 5 minutes
c. In groups of 4, discuss possible reasons and come to consensus (10
minutes)
d. Share reasons with class (10 minutes)
2. Movie introducing biodiesels
10
Below are several links that could be used to provide background information for
students.
 http://teachers.yale.edu/curriculum/search/viewer.php?skin=h&page=main
&id=initiative_07.05.03_u
 http://biodiesel.org/multimedia/audiovideo/
 http://www.eoearth.org/article/exxon_valdez_oil_spill
 http://www.cnn.com/SPECIALS/2010/gulf.coast.oil.spill/
 http://video.aol.com/video-detail/gulf-oil-spill/1246659475
Step-By-Step Procedures:
Day 1
1. Why are alternatives to gasoline and diesel oil needed?
a. I think, We think Activity
b. Share the question with the class and ask each student to list possible
reasons 5 minutes
c. In groups of 4, discuss possible reasons and come to consensus (10
minutes)
d. Share reasons with class (10 minutes)
2. Movie introducing biodiesels
3. Exploring the Chemistry of Oils
a. Use a computer with internet access to go to http://highered.mcgrawhill.com/sites/0073048763/student_view0/chapter11/figures_alive_.html
b. Follow the prompts on the screen to explore the chemistry of oils
4. From Fryer to Fuel PowerPoint
5. Model the reaction of triglycerides with methanol to produce glycerol and fatty
acid methyl esters
Day 2
6. Titrate the oil to determine amount of KOH needed – Follow procedure on lab
sheet in Appendix 1
a. Half of groups use unused vegetable oil
b. Half of groups use used vegetable oil
c. Compare/Contrast results
d. Answer questions on lab sheet
7. Prepare the biodiesel - Follow Procedure on lab sheet in Appendix 1
Day 3
8. Separate the biodiesel from the glycerin – Follow procedure on lab sheet in
Appendix 1.
a. Save glycerin for further testing.
b. Test the pH of the unwashed biodiesel - Follow procedure on lab sheet in
Appendix 1.
9. Wash the biodiesel – Follow procedure on lab sheet in Appendix 1
Day 4 and 5
10. Separate and dry the biodiesel - Follow procedure on lab sheet in Appendix 1.
11
a. Test the pH of the washed biodiesel - Follow procedure on lab sheet in
Appendix 1.
b. Answer the questions on the lab sheet
11. Complete the comparative testing of vegetable oil, diesel oil and biodiesel –
Follow the procedures on the lab sheets in Appendix 1.
a. Answer questions on lab sheets
Day 6
12. Chain notes summary of “What is biodiesel?”
13. Summary essay on choice of topic
a. Describe the production of biodiesel
b. Compare the properties of biodiesel, diesel oil and vegetable oil
c.
Lesson Materials to Be Attached:
 Introduction to Biodiesel Movie
 From Fryer to Fuel PowerPoint
 Biodiesel Lab Sheets
 Chemistry in Context Foods We Eat Activity to develop understanding of oil
chemistry http://highered.mcgrawhill.com/sites/0073048763/student_view0/chapter11/figures_alive_.html
 Biodiesel Reaction Worksheet
Assessment:
Write a 5 paragraph essay on biodiesel. Include information about the chemistry of oils
and the chemical process of making biodiesel, the properties of biodiesel, and the
advantages and disadvantages of biodiesel oil as an alternative fuel.
Closure (Reflect Anticipatory Set): Chain Notes Summary
Question: What is biodiesel?
Procedure: Prepare a paper with the question at the top for each group. Separate
class into groups of 4-6. Read the directions and allow the students to begin. Call time
when groups are no longer able to add to the chain notes. Conclude by constructing a
class answer to the question using contributions from each group.
Read these directions to the class: Today we will be using a strategy called Chain Notes
to summarize our learning about biodiesel.- Each group will be writing a chain response
to the question “What is biodiesel?” Responses can include definitions, chemistry,
properties, uses, advantages, disadvantages, examples, non-examples and more. One
student will start by writing a one or two sentence response to the question. The sheet
will then be passed to the next student who will read the previous responses and add a
response of his own. The sheet will continue to be passed around the group until time is
called. After time is called, we will share results with the class. Are there any questions
12
before we begin?
Materials:
To Titrate the Oil
 Used cooking oil (available from local restaurants-free)
 Soy, canola or other cooking oil (available from grocery store - $6/gallon)
 Isopropanol (available as Iso-Heet ($2/350 mL) from automotive supply store or
from science supply such as Flinn Scientific)
 Potassium hydroxide ($9/500 g lab grade)
(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=20656)
 Diesel fuel (purchased from gas station) ($3/gallon)
 Storage container for diesel fuel ($7 at Walmart)
 0.5% Phenophthalein indicator ($5/100 mL)
(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=20703)
 Eyedropper for phenolphthalein if not included in bottle
 Titration buret ($50)
(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=19306)
 Buret clamp ($14)
(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=16911)
 Ring Stand ($15)
(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=16920)
 250 mL beaker ($3)
(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=19288)
 5 mL syringe (available free from most pharmacies)
To prepare and separate biodiesel
 Used cooking oil (available from local restaurants-free)
 Soy, canola or other cooking oil (available from grocery store - $6/gallon)
 Potassium hydroxide ($9/500 g lab grade)
(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=20656)
 Methanol (available as Heet ($2/350 mL) from automotive supply store or from
science supply such as Flinn Scientific)






Pint mason jar (Walmart $7/dozen) or 500 mL separatory funnels ($60 each)
(http://www.indigo.com/glass/separatory-filter-funnels.html)
If separatory funnels are not available, 16 oz HDPE bottles with pull caps can be
used to separate the biodiesel from the glycerol ($12 for 12 bottles)
(http://www.sks-bottle.com/340c/fin41g.html)
Hot plate ($165)
(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=21765)
Balance
250 mL beaker
100 mL graduated cylinder
13
Determining the pH of Washed and Unwashed Biodiesel
 Wide Range pH paper ($16/roll)
(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=14256)
Comparing the solvent properties of diesel oil, biodiesel oil and vegetable oil.
 Diesel fuel (purchased from gas station) ($3/gallon)
 Storage container for diesel fuel ($7 at Walmart)
 Soy, canola or other cooking oil (available from grocery store - $6/gallon)
 Biodiesel sample produced earlier in lab
 12 mL glass vials with caps (test tubes with cork stoppers may also be used)
(available from SKS Bottle-$62/72 vials http://www.sksbottle.com/340c/fin12a.html)
 0.5 cm x 4 cm strips cut from a Styrofoam cup
Comparative viscosity of vegetable oil, diesel oil and biodiesel
 Diesel fuel (purchased from gas station) ($3/gallon)
 Storage container for diesel fuel ($7 at Walmart)
 Soy, canola or other cooking oil (available from grocery store - $6/gallon)
 Biodiesel sample produced earlier in lab
 Plastic clipboard (available from Walmart - $3)
 Eye droppers or disposable pipettes ($40/pkg of 400
(http://www.flinnsci.com/store/scripts/prodView.asp?idProduct=18845)
Observing Biodiesel at Different Temperatures
 Diesel fuel (purchased from gas station) ($3/gallon)
 Storage container for diesel fuel ($7 at Walmart)
 Soy, canola or other cooking oil (available from grocery store - $6/gallon)
 test tubes ($3.20 each)
(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=19407)
 ice bath with salt
 freezer (optional)
 Thermometers ($10 each)
(http://www.flinnsci.com/store/scripts/prodView.asp?idproduct=17278)
14
Titration of Oil to Determine Amount of KOH Needed for Reaction
Materials
1. Isopropyl alcohol
2. 2 150 mL beakers
3. buret stand and buret
4. 0.100 % KOH
5. 0.1% phenolphthalein
6. magnetic stirrer
Procedure
1. Place 40 mL isopropyl alcohol into 150 mL beaker
2. Add 4.0 mL oil and mix with stirrer
3. Add 8 drops phenolphthalein solution to beaker
3. Add KOH solution to buret and record volume
4. Add KOH solution to beaker while stirring until a persistent pink color is observed.
The pink color should be observed for at least 30 seconds.
5. Record the volume of the KOH solution in the buret
6. Calculate and record the volume of KOH used for titration
7. Repeat procedure 2 more times
8. Average results
9. Calculate the mass in g of KOH needed for 0.200 liter of oil using the following
equation
g KOH per 200 mL of oil = (Volume KOH used + 7)(0.200)
4
Data and Calculations
Oil Tested ____________________________________
Trial
Initial KOH
Volume (mL)
Final KOH
Volume (mL)
g KOH per 200 mL of oil =
15
Volume KOH
Used (mL)
Average
Volume KOH
Used (mL)
Preparation of Biodiesel
Materials
1. KOH
2. Methanol
3. Vegetable oil or used oil
4. Hot plate
5. Mason jar and pull top bottle or separatory funnel
6. Water
Procedure
1. Weigh out necessary g of KOH (results from titration calculation)
2. Dissolve the KOH in 40 mL methanol by swirling the KOH in the methanol in
a closed glass mason jar. This produces methoxide, a strong caustic base,
which can cause severe burns to skin and eyes.
3. Heat 200 mL oil to 60 C using a hot plate (may also use a mass of 184 g oil)
4. Open container of methoxide, add warm oil and fully close container
5. Shake vigorously for 10 minutes
6. Pour into separatory funnel or bottle with pull spout. If in bottle, turn bottle
upside down and place in beaker. Allow to separate for at least 6 hours
7. Separate the lower layer of glycol from the upper layer of biodiesel
Analysis
1. What signs of a chemical reaction did you observe as you prepared the
biodiesel and allowed it to settle?
2. What physical property of the glycerol and biodiesel causes the glycerol to
separate to the bottom of the bottle?
3. Can you propose a reason that glycerol and biodiesel do not form a
homogeneous mixture based on the structure of the biodiesel and glycerol?
4. Extra methanol is added to the reaction to help make the reaction go to
completion. Using what you know about the structures of the methanol,
biodiesel and glycerol, is the excess methanol in the biodiesel layer or the
glycerol layer at the end of the reaction?
16
Separating the Biodiesel and Glycerol and Washing the Biodiesel
1. Allow biodiesel/glycerol mixture to sit for at least 6 hours in bottle with pull
cap
2. Without squeezing the bottle, hold the bottle above a jar or beaker. Open the
cap and GENTLY squeeze out the glycerol. (Wear gloves, this might be
messy). Recap the bottle when all the glycerol has been removed.
3. Heat 200 mL water (200 g) to 60 C and add to bottle containing biodiesel.
Shake gently for 10 minutes.
4. Turn bottle upside down and allow to settle overnight.
5. Separate the water by holding the bottle upside down over a beaker or jar.
Without squeezing the bottle, open lid. Gently squeeze to remove water.
6. Dry the remaining biodiesel by heating it to 60 C in a beaker on a hot plate for
5 minutes.
Determining the pH of Washed and Unwashed Biodiesel
Materials
1. Samples of washed and unwashed biodiesel
2. wide range pH paper
Procedure
1. place of drop of the sample to be tested on the pH paper and compare the color
of the paper to the reference to determine the pH of the sample
Analysis
1. How did the pH change when the biodiesel was washed?
2. Why is it important to wash the biodiesel before using it in an engine?
17
Comparing the solvent properties of diesel oil, biodiesel oil and
vegetable oil.
Obtain samples of diesel oil, biodiesel oil and canola or soy vegetable oil. If biodiesel
has been prepared in a previous laboratory, that biodiesel and the oil used to prepare it
can be tested.
Materials needed
12 mL glass vials with caps (test tubes with cork stoppers may also be used)
Biodiesel
Diesel oil
Vegetable oil
0.5 cm x 4 cm strips cut from a Styrofoam cup
Procedure
1. Add 10 mL of biodiesel into a glass vial
2. Add 10 mL of diesel into a second glass vial
3. Add 10 mL of vegetable oil into a third glass vial.
4. Into each of the prepared test tubes, add a Styrofoam strip to each vial
5. Seal each test tube with the cap and shake the mixture
6. Stop every 20 seconds and record observations
7. Continue shaking the tubes until the Styrofoam in one test tube has completely
dissolved. Stop and record your final observations, including the time required to
dissolve the strip.
Analysis
1. Compare the solvent properties of biodiesel, vegetable oil and diesel oil. Which
substance was the best solvent for Styrofoam?
2. How might the solvent properties of a fuel be important in use in an engine?
3. What problems might be observed in changing fuels from one solvent profile to
another?
4. What other uses for a non-toxic solvent might you suggest?
18
Comparative Viscosity of Biodiesel, Diesel, and Vegetable Oil
Materials
1. Plastic sheet
2. Permanent marker
3. Ruler
4. Timer
5. Samples of biodiesel, diesel, and vegetable oil
6. eye dropper or disposable pipettes
Procedure
1. Prepare a plastic sheet by marking a ‘start’ line using a permanent marker.
2. Set up a lower ‘stop’ for the bottom edge of the plastic sheet by securing a ruler,
dowel, or similar object to a lab bench so the lower edge of the plastic sheet ends in
the same location for each run.
3. Set up something to hold the upper end of the plastic sheet at the same height and
location for each run. It the object used is large enough, such as a box, the plastic
sheet can be loaded on it and then the lower edge dropped quickly to the ‘stop’ on the
lab bench so that the same angle is reproduced with each run.
4. On the level plastic sheet, place 3 drops of a sample of biodiesel on the start line to
form one larger drop. Multiple runs of the same sample may be completed by making
additional starting drops on the start line. It is suggested to use 3 runs of the same
sample to find the average distance traveled.
5. After the plastic sheet is loaded with samples, tip the free (lower) edge of the plastic
sheet down to the ‘stop’ and let the samples flow for 10 seconds. At 10 seconds,
return the plastic sheet to a horizontal position and determine the distance traveled for
each sample on the sheet.
6. Wipe the samples off of the plastic sheet and then wash twice with warm soapy water,
rinse until it is ‘squeaky clean’ and dry the sheet when finished. If the sheet has
unusual reflection and streaks, rewash until the surface appears uniform.
Samples with the lowest viscosity will travel the farthest.
1. What was the average distance traveled by the drops of biodiesel, vegetable oil and
diesel oil?
2. How do the viscosities of biodiesel, diesel and vegetable oil compare?
3. Why might the viscosity of a fuel be important to the operation of an engine?
19
Determining the Density of the Biodiesel and Glycerol
Materials
1. Balance
2. 10 mL graduated cylinder
3. biodiesel and glycerol
4. Dropper
Procedure
1. Place 10 mL graduated cylinder on balance and tare the balance
2. Add 10.0 mL of biodiesel to graduated cylinder
3. Place graduated cylinder on the balance and determine mass in grams of the
biodiesel
4. Calculate the density of the biodiesel using density = mass/volume
5. Repeat the procedure using glycerol
Analysis
1. What was the density of the biodiesel and the glycerol?
2. If the biodiesel and glycerol will not mix, which substance would make up the
bottom layer?
3. Does this result match your observations when the biodiesel was prepared?
20
Observing Biodiesel at Different Temperatures
This observation can be made comparing the properties of diesel, biodiesel, and oil
or comparing the properties of biodiesels prepared from different feedstock oils.
Materials
1. test tubes
2. ice bath with salt
3. freezer
4. biodiesel, diesel, vegetable oils
5. Thermometers
Procedure
1.
2.
3.
4.
Prepare ice bath
Add 15 mL of biodiesel to a test tube
Put a thermometer in the solution
Place the test tube in ice bath. Remove the test tube from the bath every few
seconds to check the solution for cloudiness. Record the temperature when
the solution becomes cloudy. This temperature is known as the cloud point.
5. Warm the solution to room temperature and repeat 2 more times
6. Repeat steps 1-5 with other solutions
7. Place a sample of all solutions in a freezer. Observe at 15 minute intervals.
Record the temperature when the solution will no longer pour. This
temperature is known as the pour point.
Sample
Cloud Point
Average Cloud Pour Point (C) Average Pour
(C)
Point (C)
Point (C)
Analysis
1. How did the cloud points and pour points of the fuels tested compare?
2. Why might the cloud point and pour point of a fuel be an issue when the fuel is
used in an engine?
21
Answer Key Titration of Oil to Determine Amount of KOH
Needed for Reaction
Materials
1. Isopropyl alcohol
2. 2 150 mL beakers
3. buret stand and buret
4. 0.100 % KOH
5. 0.1% phenolphthalein
6. magnetic stirrer
Procedure
1. Place 40 mL isopropyl alcohol into 150 mL beaker
2. Add 4.0 mL oil and mix with stirrer
3. Add 8 drops phenolphthalein solution to beaker
3. Add KOH solution to buret and record volume
4. Add KOH solution to beaker while stirring until a persistent pink color is observed.
The pink color should be observed for at least 30 seconds.
5. Record the volume of the KOH solution in the buret
6. Calculate and record the volume of KOH used for titration
7. Repeat procedure 2 more times
8. Average results
9. Calculate the mass in g of KOH needed for 0.200 liter of oil using the following
equation
g KOH per 200 mL of oil = (Volume KOH used + 7)(0.200)
4
Data and Calculations
Oil Tested ____________________________________
Trial
Initial KOH
Volume (mL)
Final KOH
Volume (mL)
Unused oil
Average
Volume KOH
Used (mL)
0.25-0.75 mL
Used oil
2-15 mL
g KOH per 200 mL of oil =
22
Volume KOH
Used (mL)
Preparation of Biodiesel
Materials
7. KOH
8. Methanol
9. Vegetable oil or used oil
10. Hot plate
11. Mason jar and pull top bottle or separatory funnel
12. Water
Procedure
1. Weigh out necessary g of KOH (results from titration calculation)
2. Dissolve the KOH in 40 mL methanol by swirling the KOH in the methanol in
a closed glass mason jar. This produces methoxide, a strong caustic base that
can cause severe burns to skin and eyes.
3. Heat 200 mL oil to 60 C using a hot plate (may also use a mass of 184 g oil)
4. Open container of methoxide, add warm oil and fully close container
5. Shake vigorously for 10 minutes
6. Pour into separatory funnel or bottle with pull spout. If in bottle, turn bottle
upside down and place in beaker. Allow to separate for at least 6 hours
7. Separate the lower layer of glycol from the upper layer of biodiesel
Analysis
1. What signs of a chemical reaction did you observe as you prepared the
biodiesel and allowed it to settle?
There was a color change and new substances were produced as evidenced by the
change in viscosity and the appearance of a dark layer at the bottom of the
reaction vessel.
2. What physical property of the glycerol and biodiesel causes the glycerol to
separate to the bottom of the bottle?
The glycerol is more dense than the biodiesel.
3. Can you propose a reason that glycerol and biodiesel do not form a
homogeneous mixture based on the structure of the biodiesel and glycerol?
The long carbon chains of the biodiesel make it non-polar, while the alcohol
groups on the glycerol make it polar.
4. Extra methanol is added to the reaction to help make the reaction go to
completion. Using what you know about the structures of the methanol,
biodiesel and glycerol, is the excess methanol in the biodiesel layer or the
glycerol layer at the end of the reaction?
The methanol is polar and will be attracted to the glycerol layer.
23
Separating the Biodiesel and Glycerol and Washing the Biodiesel
1. Allow biodiesel/glycerol mixture to sit for at least 6 hours in bottle with pull
cap
2. Without squeezing the bottle, hold the bottle above a jar or beaker. Open the
cap and GENTLY squeeze out the glycerol. (Wear gloves, this might be
messy). Recap the bottle when all the glycerol has been removed.
3. Heat 200 mL water (200 g) to 60 C and add to bottle containing biodiesel.
Shake gently for 10 minutes.
4. Turn bottle upside down and allow to settle overnight.
5. Separate the water by holding the bottle upside down over a beaker or jar.
Without squeezing the bottle, open lid. Gently squeeze to remove water.
6. Dry the remaining biodiesel by heating it to 60 C in a beaker on a hot plate for
5 minutes.
Determining the pH of Washed and Unwashed Biodiesel
Materials
1. Samples of washed and unwashed biodiesel
2. wide range pH paper
Procedure
1. place of drop of the sample to be tested on the pH paper and compare the color
of the paper to the reference to determine the pH of the sample
Analysis
1. How did the pH change when the biodiesel was washed?
The pH decreased when the biodiesel was washed.
2. Why is it important to wash the biodiesel before using it in an engine?
High pH liquids could cause corrosion in the engine.
24
Comparing the solvent properties of diesel oil, biodiesel oil and
vegetable oil.
Obtain samples of diesel oil, biodiesel oil and canola or soy vegetable oil. If biodiesel
has been prepared in a previous laboratory, that biodiesel and the oil used to prepare it
can be tested.
Materials needed
12 mL glass vials with caps (test tubes with cork stoppers may also be used)
Biodiesel
Diesel oil
Vegetable oil
0.5 cm x 4 cm strips cut from a Styrofoam cup
Procedure
1. Add 10 mL of biodiesel into a glass vial
2. Add 10 mL of diesel into a second glass vial
3. Add 10 mL of vegetable oil into a third glass vial.
4. Into each of the prepared test tubes, add a Styrofoam strip to each vial
5. Seal each test tube with the cap and shake the mixture
6. Stop every 20 seconds and record observations
7. Continue shaking the tubes until the Styrofoam in one test tube has completely
dissolved. Stop and record your final observations, including the time required to
dissolve the strip.
Analysis
1. Compare the solvent properties of biodiesel, vegetable oil and diesel oil. Which
substance was the best solvent for Styrofoam?
The biodiesel dissolved the Styrofoam and the vegetable oil and diesel oil had no effect
on the Styrofoam
2. How might the solvent properties of a fuel be important in use in an engine?
Care must be taken that the parts used in the engine are resistant to the solvent properties
of the fuel. Good solvent properties of the fuel will help to keep the engine clean.
3. What problems might be observed in changing fuels from one solvent profile to
another?
Fuel filters might plug if the solvent properties of the fuel change because deposits in the
engine or fuel line left by one fuel might be partially dissolved a fuel with stronger
solvent properties. Components in fuel lines and engines must be designed for the
fuel with the most aggressive solvent properties.
4. What other uses for a non-toxic solvent might you suggest?
A non-toxic solvent could be used as a de-greaser or a graffiti remover.
25
Comparative Viscosity of Biodiesel, Diesel, and Vegetable Oil
Materials
1. Plastic sheet
2. Permanent marker
3. Ruler
4. Timer
5. Samples of biodiesel, diesel, and vegetable oil
6. eye dropper or disposable pipettes
Procedure
1. Prepare a plastic sheet by marking a ‘start’ line using a permanent marker.
2. Set up a lower ‘stop’ for the bottom edge of the plastic sheet by securing a ruler,
dowel, or similar object to a lab bench so the lower edge of the plastic sheet ends in
the same location for each run.
3. Set up something to hold the upper end of the plastic sheet at the same height and
location for each run. It the object used is large enough, such as a box, the plastic
sheet can be loaded on it and then the lower edge dropped quickly to the ‘stop’ on the
lab bench so that the same angle is reproduced with each run.
4. On the level plastic sheet, place 5 drops of a sample of biodiesel on the start line to
form one larger drop. Multiple runs of the same sample may be completed by making
additional starting drops on the start line. It is suggested to use 3 runs of the same
sample to find the average distance traveled.
5. After the plastic sheet is loaded with samples, tip the free (lower) edge of the plastic
sheet down to the ‘stop’ and let the samples flow for 10 seconds. At 10 seconds,
return the plastic sheet to a horizontal position and determine the distance traveled for
each sample on the sheet.
6. Wipe the samples off of the plastic sheet and then wash twice with warm soapy water,
rinse until it is ‘squeaky clean’ and dry the sheet when finished. If the sheet has
unusual reflection and streaks, rewash until the surface appears uniform.
Samples with the lowest viscosity will travel the farthest.
1. What was the average distance traveled by the drops of biodiesel, vegetable oil and
diesel oil?
2. How do the viscosities of biodiesel, diesel and vegetable oil compare?
Vegetable oil has a much higher viscosity than diesel oil and biodiesel. The diesel oil
and biodiesel have similar viscosities at room temperature.
3. Why might the viscosity of a fuel be important to the operation of an engine?
Engines are designed with a fuel with a specific viscosity. Increases in viscosity could
change how quickly the fuel enters combustion chambers and whether it sprays into
the chamber or dribbles into the chamber.
26
Determining the Density of the Biodiesel and Glycerol
Materials
1. Balance
2. 10 mL graduated cylinder
3. biodiesel and glycerol
4. Dropper
Procedure
1. Place 10 mL graduated cylinder on balance and tare the balance
2. Add 10.0 mL of biodiesel to graduated cylinder
3. Place graduated cylinder on the balance and determine mass in grams of the
biodiesel
4. Calculate the density of the biodiesel using density = mass/volume
5. Repeat the procedure using glycerol
Analysis
1. What was the density of the biodiesel and the glycerol?
Biodiesel = 0.88 g/mL
Glycerol = 1.07 g/mL
2. If the biodiesel and glycerol will not mix, which substance would make up the
bottom layer?
The glycerol would be in the bottom layer because of its higher density.
3. Does this result match your observations when the biodiesel was prepared?
Yes, the biodiesel was the top layer and the glycerol was the bottom layer.
27
Observing Biodiesel at Different Temperatures
This observation can be made comparing the properties of diesel, biodiesel, and oil
or comparing the properties of biodiesels prepared from different feedstock oils.
Materials
1. test tubes
2. ice bath with salt
3. freezer
4. biodiesel, diesel, vegetable oils
5. Thermometers
Procedure
8. Prepare ice bath
9. Add 15 mL of biodiesel to a test tube
10. Put a thermometer in the solution
11. Place the test tube in ice bath. Remove the test tube from the bath every few
seconds to check the solution for cloudiness. Record the temperature when
the solution becomes cloudy. This temperature is known as the cloud point.
12. Warm the solution to room temperature and repeat 2 more times
13. Repeat steps 1-5 with other solutions
14. Place a sample of all solutions in a freezer. Observe at 15 minute intervals.
Record the temperature when the solution will no longer pour. This
temperature is known as the pour point.
Sample
Cloud Point
Average Cloud Pour Point (C) Average Pour
(C)
Point (C)
Point (C)
Analysis
1. How did the cloud points and pour points of the fuels tested compare?
Vegetable oil had the highest cloud points and pour points, followed by biodiesel and
than diesel oil.
2. Why might the cloud point and pour point of a fuel be an issue when the fuel
is used in an engine?
In cold weather, a fuel must remain a free flowing liquid. High cloud points and pour
points could mean the fuel would plug fuel filters and the engine would not run.
Appendix 2
28
Density Problems
1. What is the density of a biodiesel sample with a mass of 28.9 g and a
volume of 32.6 mL?
2. A sample of biodiesel has a volume of 14.3 liters. What is the mass in
kilograms of the sample if the density of the biodiesel sample is 0.886 g/cm 3?
3. If 500 g of canola oil was needed to prepare a sample of biodiesel, how
many mL of canola oil should be measured out for the reaction? Assume the
density of canola oil is 0.92 g/mL.
4. The mass of biodiesel in a barrel is 148 kg. How many liters of biodiesel are
in the barrel if the density of biodiesel is 0.886 g/cm 3?
5. Determine the mass in kilograms of a 20.0 gallon sample of biodiesel.
Assume a density of 0.8855 g/cm3 for the biodiesel. There are 4 quarts in a
gallon and 1.063 quarts in 1 liter.
6. An unlabeled sample left out on the lab bench was either canola oil or
the biodiesel prepared from the canola oil. The density of canola oil at room
temperature is 0.92 g/mL. The density of the biodiesel is 0.886 g/mL. If 500 mL
of the unlabeled sample had a mass of 443 grams, is the unlabeled sample
most likely canola oil or biodiesel?
29
Density Problems- Answers
1. What is the density of a biodiesel sample with a mass of 28.9 g and a
volume of 32.6 mL?
0.886 g/mL
2. A sample of biodiesel has a volume of 14.3 liters. What is the mass in
kilograms of the sample if the density of the biodiesel sample is 0.886 g/cm 3?
12.7 kg
3. If 500.0 g of canola oil was needed to prepare a sample of biodiesel, how
many mL of canola oil should be measured out for the reaction? Assume the
density of canola oil is 0.92 g/mL.
540 g oil
4. The mass of biodiesel in a barrel is 148 kg. How many liters of biodiesel are
in the barrel if the density of biodiesel is 0.886 g/cm 3?
167 L
5. Determine the mass in kilograms of a 20.0 gallon sample of biodiesel.
Assume a density of 0.8855 g/cm3 for the biodiesel. There are 4 quarts in a
gallon and 1.063 quarts in 1 liter.
66.6 kg
6. An unlabeled sample left out on the lab bench was either canola oil or
the biodiesel prepared from the canola oil. The density of canola oil at room
temperature is 0.92 g/mL. The density of the biodiesel is 0.886 g/mL. If 500 mL
of the unlabeled sample had a mass of 442 grams, is the unlabeled sample
most likely canola oil or biodiesel?
30
Density = 0.884 so the sample is most likely biodiesel
Molar mass problems
Data taken from
http://www.biodiesel.org/pdf_files/fuelfactsheets/Weight&Formula.PDF
accessed 6/28/10 by Jo McCormick
Typical Soybean Oil Methyl Ester (Biodiesel) Profile
Weight Mol.
Fatty Acid Percent
Formula of Methyl Ester
Palmitic
12.0
C15H31CO2CH3
Stearic
5.0
C17H35CO2CH3
Oleic
25.0
C17H33CO2CH3
Linoleic
52.0
CH3(CH2)4CH=CHCH2CH=CH(CH2)7 CO2CH3
Linolenic
6.0
CH3(CH2CH=CH)3(CH2)7 CO2CH3
1. Use the formulas for each methyl ester to determine the molar mass
a. Palmitic acid methyl ester
b. stearic acid methyl ester
c. Oleic acid methyl ester
d. linoleic acid methyl ester
e. linolenic acid methyl ester
2. Do a weighted average to determine the average molar mass of the
biodiesel produced using soy oil. (32.455 + 14.926 + 74.125 + 153.130 + 17.548
= 292.18)
31
Molar mass problems ANSWERS
Data taken from
http://www.biodiesel.org/pdf_files/fuelfactsheets/Weight&Formula.PDF
accessed 6/28/10 by Jo McCormick
Typical Soybean Oil Methyl Ester (Biodiesel) Profile
Weight Mol.
Fatty Acid Percent
Formula of Methyl Ester
Palmitic
12.0
C15H31CO2CH3
Stearic
5.0
C17H35CO2CH3
Oleic
25.0
C17H33CO2CH3
Linoleic
52.0
CH3(CH2)4CH=CHCH2CH=CH(CH2)7 CO2CH3
Linolenic
6.0
CH3(CH2CH=CH)3(CH2)7 CO2CH3
1. Use the formulas for each methyl ester to determine the molar mass
a. Palmitic acid methyl ester
270.46
b. stearic acid methyl ester
298.52
c. Oleic acid methyl ester
296.50
d. linoleic acid methyl ester
294.48
e. linolenic acid methyl ester
292.46
2. Do a weighted average to determine the average molar mass of the
biodiesel produced using soy oil.
32.455 + 14.926 + 74.125 + 153.130 + 17.548 = 292.18
32
Balancing Combustion Problems
The following fatty acid methyl esters are all present in biodiesel produced
from soy oil. Balance the combustion reaction for each .
1. ____C19H34O2 + ____O2  ____CO2 + ____H2O (linoleic acid methyl ester)
2. ___ C19H36O2 + _____O2 _____CO2 + _____H2O (Oleic acid methyl ester)
3. ___ C17H34O2 + _____O2 _____CO2 + _____H2O (Palmitic acid methyl
ester)
4. ___ C19H38O2 + _____O2 _____CO2 + _____H2O (Stearic acid methyl
ester)
5. ___ C19H32O2 + _____O2 _____CO2 + _____H2O (Linolenic acid methyl
ester)
33
Balancing Combustion Problems Answers
The following fatty acid methyl esters are all present in biodiesel produced
from soy oil. Balance the combustion reaction for each .
1. 2_C19H34O2 + __53__O2  __38__CO2 + _34___H2O (linoleic acid methyl
ester)
2. ___ C19H36O2 + ___27__O2 __19___CO2 + __18___H2O (Oleic acid methyl
ester)
3. _2__ C17H34O2 + ___49__O2 __34___CO2 + __34___H2O (Palmitic acid
methyl ester)
4. _2__ C19H38O2 + ___55__O2 __38___CO2 + ___38__H2O (Stearic acid
methyl ester)
5. ___ C19H32O2 + ___26__O2 __19___CO2 + ___16__H2O (Linolenic acid
methyl ester)
34