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Chemistry Lab

Open Posted By: highheaven1 Date: 14/10/2020 High School Research Paper Writing

Please conduct the experiment then complete the lab report. This experiment takes long.

Category: Engineering & Sciences Subjects: Engineering Deadline: 24 Hours Budget: $80 - $120 Pages: 2-3 Pages (Short Assignment)

Attachment 1

CHEMISTRY

Synthesis of Biodiesel Investigation Manual

SYNTHESIS OF BIODIESEL

Overview In this investigation, students will perform a transesterification of vegetable oil in the presence of a solid catalyst to produce biodiesel. Students will test for the presence of contaminants such as soap to determine the purity of their sample.

Outcomes • Synthesize biodiesel using a solid-state catalyst. • Test synthesized biodiesel for quality. • Describe the synthesis pathway for biodiesel.

Time Requirements Preparation ..................................................................... 10 minutes Activity 1: Synthesis of Biodiesel .................... 60 minutes + 2 days Activity 2: Testing for Quality .......................................... 90 minutes

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Table of Contents

2 Overview 2 Outcomes 2 Time Requirements 3 Background 7 Materials 8 Safety 9 Activity 1 9 Activity 2 9 Disposal and Cleanup

Key Personal protective equipment (PPE)

goggles gloves apron follow link to video

photograph results and

submit

stopwatch required

warning corrosion flammable toxic environment health hazard

Key Personal protective equipment (PPE)

goggles gloves apron follow link to video

photograph results and

submit

stopwatch required

warning corrosion flammable toxic environment health hazard

Made ADA compliant by NetCentric Technologies using the CommonLook® software

Background Renewable sources of energy and fuel are becoming increasingly valuable. Unlike the most common form of diesel, which is distilled from petroleum, biodiesel can be produced from a variety of renewable sources. The adoption of alternative fuel sources, such as biodiesel, can help reduce our dependence on fossil fuels.

Biodiesel has several advantages over tradi- tional petroleum diesel. It is cleaner burning, producing less particulate matter and less carbon monoxide. In post 2010 vehicles with modern emission control technologies, nitrogen oxides (NOx ) emissions are comparable to tradi- tional diesel. Though biodiesel still releases carbon dioxide into the atmosphere, that carbon had to be recently sequestered into the tissues of the plants from which the oil was made, so there is no net increase of carbon dioxide in the atmosphere. Biodiesel is biodegradable and non-toxic, and can be used in several ways. Diesel engines require no modifications in order to use it as a fuel, though engines that have run on petroleum diesel may experience clogged filters and pipes since biodiesel strips deposits left behind by other petroleum diesel. Biodiesel can also be used in place of heating oil in homes.

The biodiesel production process has surpris- ingly few steps. Generally, all that is required is a pure vegetable oil, a solid base like potassium hydroxide or calcium hydroxide, and meth- anol. Calcium hydroxide, for example, is mixed thoroughly with methanol to produce calcium methoxide. Vegetable oil is then added to the methoxide and mixed. The triglycerides in the oil react with the methoxide through a trans- esterification reaction to create methyl esters (biodiesel) and glycerol. The solution then sepa-

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rates into a layer of biodiesel and a layer of glycerol, which facilitates the easy collection of the biodiesel.

A transesterification reaction is the process of exchanging an organic ester group with an alcohol group between two molecules. An ester is typically represented as RCOOR1 where each R represents a carbon chain. The carbon has one oxygen bound to it with a double bond, one oxygen bound with a single bond, and a carbon from the carbon chain. In this reaction the alcohol group from the methanol will be exchanged with each of the ester groups on the triglyceride.

In practice, the synthesis of biodiesel is compli- cated by impurities in the oil, such as excess water, free fatty acids, or other chemicals that may lead to side products in the transesterifica- tion reaction.

The first step in the process of biodiesel production is choosing a stock of oil to work from. This can be derived from a variety of sources, including animal fats, or vegetable oils such as corn, canola, or soy. The oil can be produced from algae or can even be recovered from sewage or deep fryers. In general, an oil that has been previously used, such as in a deep fryer, has more contaminants that will need to be removed through filtration or other chemical processes, and the oil must be subjected to a drying process to remove excess water.

Another potential contaminant can arise in the oil itself, in the form of free fatty acids. These fatty acids can interfere with the transesterification reaction and generate soap instead of biodiesel.

continued on next page

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Background continued

SYNTHESIS OF BIODIESEL

Biodiesel Synthesis First, the calcium methoxide reacts with the methanol, creating a negative dipole at an oxygen and a positive dipole at a hydrogen (Figure 2). This molecule will react in the last step of the process.

Figure 2.

Methoxide Synthesis

Figure 1.

In this investigation, corn oil will be used for the creation of your biodiesel. Because the oil was not previously used, filtration will not be necessary before the synthesis.

The provided methanol is a required reagent for the transesterification reaction. The calcium hydroxide reacts with the methanol (CH3OH) to yield calcium methoxide, Ca(OCH3)2, which acts as a catalyst for the subsequent reaction.

continued on next page

Detailed Synthesis The first reaction in this activity is the synthesis of calcium methoxide. Calcium hydroxide is added to methanol where it reacts to form calcium methoxide (Figure 1). In the second reaction, the calcium methoxide acts as a cata- lyst, facilitating the transesterification of meth- anol with triglycerides to produce glycerol and fatty acid esters.

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A second calcium methoxide then reacts with a fatty acid on a triglyceride, with the calcium associating with the oxygen of the ester, and an oxygen of the calcium methoxide reacting with the carbon of the ester. This product is then used in the final step of the reaction (Figure 3).

Figure 3.

continued on next page

In the third step of the reaction, the step one product reacts with the step two product to form the methyl ester (biodiesel), a diglyceride, and regenerates the two catalyst molecules of calcium methoxide. The process then repeats until each fatty acid is used up and the end products are three methyl esters and a glycerol molecule (Figure 4).

Background continued

SYNTHESIS OF BIODIESEL

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Figure 4.

Typically, after a batch of biodiesel is created, a bevy of tests are conducted on the sample, testing for the presence of a multitude of molecules and properties. For the purposes of this investigation, pH, density, and the presence of triglycerides will be tested for. The pH test detects free fatty acids that have not reacted in the process, these are indicated by a lower pH and typically are the result of a lower quality stock oil, with biodiesel having a typical pH of 7 to 9. Density is a test of biodiesel quality as the density of biodiesel of 0.88 g/mL. The final test is for the presence of unreacted triglycerides, or intermediates, such as a diglyceride. The presence of these indicates an incomplete reaction.

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Materials Included in the materials kit:

Needed, but not supplied: • Paper towel • Water, bottled or purified

Needed from the equipment kit:

Reorder Information: Replacement supplies for the Synthesis of Biodiesel investigation can be ordered from Carolina Biological Supply Company, kit 580372.

Call 800-334-5551 to order.

Glass test tube

Electronic balance

Graduated cylinder, 10 mL

Methanol, 30-mL bottle

Vegetable oil, 30-mL bottle

Glass vial, 3-dram

pH paper Plasic dropping pipet

Calcium hydroxide, 1-g glass vial

Safety Wear your goggles, gloves, and a lab apron at all times while conducting this investigation.

Read all the instructions for this laboratory activity before beginning. Follow the instructions closely, and observe established laboratory safety practices, including the use of appro- priate personal protective equipment (PPE) as described in the Safety and Activity sections.

Methanol is flammable. Keep this chemical away from any heat or flame sources.

Calcium hydroxide causes skin irritation.

Calcium hydroxide is a corrosive material and can cause serious eye damage.

Methanol can cause organ damage if ingested. Keep away from food sources.

Methanol may be toxic if in contact with skin.

Do not eat, drink, or chew gum while performing this activity. Wash your hands with soap and water before and after performing the activity. Clean up the work area with soap and water after completing the investigation. Keep pets and children away from lab materials and equipment.

SYNTHESIS OF BIODIESEL

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ACTIVITY 1

A Synthesis of Biodiesel

1. On the balance weigh approximately 0.02 grams of calcium hydroxide into the 3-dram vial.

2. Measure 8 mL of methanol with a graduated cylinder.

3. Add methanol to the vial. 4. Cap vial and shake vigorously. Allow vial to sit

for 10 minutes, shaking occasionally. 5. Carefully open cap away from your face as

some pressure may build up. 6. Measure 1 mL of vegetable oil with a

graduated cylinder. 7. Add vegetable oil to the vial, and cap the vial. 8. Shake vial vigorously. 9. Allow the reaction to occur over 48 hours.

Shake the vial occasionally to allow the solid calcium methoxide to react with the triglycerides.

ACTIVITY 2

A Testing for Quality

1. Weigh an empty 10-mL graduated cylinder and record the mass in Data Table 1.

2. Using a pipet, extract some biodiesel from the vial. The biodiesel should be the top liquid layer.

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Note: this activity needs to be completed at least 48 hours before you intend to complete Activity 2.

3. Dispense ~1 mL of biodiesel into the graduated cylinder. Record the exact volume in Data Table 1.

4. Weigh the graduated cylinder with biodiesel and record the mass in Data Table 1.

5. Calculate the mass of the biodiesel. mass biodiesel = mass of g.c. w/biodiesel—

mass of g.c. 6. Calculate the density of the biodiesel.

density = mass/volume 7. Take a strip of pH paper and dip it in the

biodiesel. 8. Record the pH in Data Table 1. 9. Dispense ~1 mL of biodiesel into a glass test

tube. 10. Measure 7 mL of methanol and add it to the

test tube. 11. With a gloved hand, place your thumb

over the mouth of the test tube and shake vigorously.

12. Place the test tube in the test tube rack and allow it to sit for 10 minutes.

13. Record whether an insoluble layer forms. This layer contains unreacted triglycerides or intermediates.

Disposal and Cleanup 1. Dispose of solutions down the drain with the

water running. Allow the faucet to run a few minutes to dilute the solutions.

2. Rinse and dry the lab equipment and return the materials to your equipment kit.

3. Sanitize the workspace.

ACTIVITY

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Mass of Graduated Cylinder

Volume of Biodiesel

Mass of G.C. +

Biodiesel Mass of

Biodiesel Density of Biodiesel

pH of Biodiesel

Presence of Intermediates?

(y/n)

Data Table 1.

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NOTES

CHEMISTRY Synthesis of Biodiesel Investigation Manual

CB780821703

Carolina Biological Supply Company www.carolina.com • 800.334.5551 ©2017 Carolina Biological Supply Company

www.carolina.com/distancelearning 866.332.4478

  • Synthesis of Biodiesel
    • Table of Contents
    • Overview
    • Outcomes
    • Time Requirements
      • Key
    • Background
      • Detailed Synthesis
      • Methoxide Synthesis
        • Figure 1.
      • Biodiesel Synthesis
        • Figure 2.
        • Figure 3.
        • Figure 4.
    • Materials
      • Included in the materials kit:
      • Needed from the equipment kit:
      • Needed, but not supplied:
    • Safety
    • ACTIVITY 1
      • A Synthesis of Biodiesel
    • ACTIVITY 2
      • A Testing for Quality
    • Disposal and Cleanup
      • Data Table 1.
    • NOTES