Biodiesel Unit Lesson 2

Transcription

1 Terminal Objective 2: produce biodiesel Biodiesel Unit Lesson 2 Performance Objective 2: Given unused cooking oil, necessary equipment and chemicals, produce biodiesel that is free of soap, dry, and ready for testing. Enabling Objectives: describe safety practices for the production of biodiesel describe the major steps to produce biodiesel from cooking oil match equipment needed for the production of biodiesel indicate why cooking oil is heated to 138 F prior to adding the catalyst describe two molecular properties that affect the separation of liquids illustrate emulsification utilize Material Safety Data Sheets (MSDS) related to biodiesel production Laboratory Hardware: Several pieces of equipment will be needed to perform this lab. Bottle and Cap Every team will need one bottle with a tight fitting cap. The bottle needs to be resistive to the corrosive elements of the chemicals that are being used. Glass is good but breaks, so be careful. Drying pan A Pyrex meatloaf pan works great. Filter paper Removes particles from final product. We use Whatman cat. # Funnel Glass funnels are good but not necessary since the chemicals don t stay in them very long. Like the graduated cylinder, one is necessary, one per group is better. Graduated cylinder It is possible to use one graduated cylinder in the lab but it should be well cleaned after each use. It is easier to have several graduated cylinders; one for methanol, one for oil and one for washing. Hot plate Better if not a flame. Used to heat cooking oil. Metal pot For heating cooking oil. If the pot has a metal handle, a hot pad will be necessary. Rocker Not necessary but good. Drying takes longer otherwise. Scale A scale to measure weight is needed. For this lab, the scale needs to be able to measure in grams with an accuracy of 0.1g. Separating funnel It is possible to use only one but best to have one per group. Thermometer For monitoring cooking oil temperature. Needs to go above 138 F. Learning Activities: 2.1 Participate in power point presentation. 2.2 Complete worksheet, Activity Sheet 2.1, Making biodiesel. 2.3 Pass safety quiz with no questions missed. 2.4 Produce biodiesel in laboratory. Biodiesel Lesson 2 page 1

2 Formative Assessment: 1. The worksheet, Activity Sheet 2.1, Making Biodiesel, will be used to assess student progress. The answers to Activity Sheet 2.1 are as follows: Section Splash-proof goggles 2. Wash hands 3. They could be harmful or fatal 4. Work in a well ventilated area or under a fume hood. 5. Always follow directions and never perform an unauthorized experiment. 6. Never return unused chemicals to their original container. 7. Ask the teacher or consult the MSDS. Section Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately. 2. Dry chemical, foam, CO2. 3. Combustible materials. 4. Keep in tightly closed containers, stored in a cool, dry, ventilated area. Protect against physical damage. Separate from incompatibles. Section F 2. A 3. J 4. D 5. B 6. H 7. E 8. I 9. G 10. K 11. C Section C 2. G 3. D 4. A 5. B 6. F 7. E Section Decrease reaction time without boiling off methanol. 2. Polar molecules are polarized. Biodiesel Lesson 2 page 2

3 3. Specific gravity is a measure of density 4. (Something similar to the picture on lesson slide #12 depicting emulsion. 2. The safety quiz will also be used to indicate student progress. The answers to the safety test are as follows: 1. T 2. T 3. F 4. T 5. F 6. F 7. F Summative Assessment: 1. A performance evaluation check sheet is used to grade student progress on an acceptable/unacceptable basis (see form at the end of this lesson). Five items are evaluated: two dealing with the process and three dealing with the product. Process Evaluation 1. Did the students follow good safety practices? 2. Did the students keep the area clean and neat while working? Did they clean up afterwards? Product Evaluation 3. Soap test is there soap in the final product? 4. Is the fuel dry can fine print be read through the biodiesel? 5. Is the reaction complete did the fuel pass a modified Jan Warnqvist s conversion test? Soap test Using a small sample of the final product, mix it with water and shake vigorously. If the water and biodiesel separate after approximately minutes, then there should be no soap left in the biodiesel. Jan Warnqvist's Conversion Test (3/27 test) This is a quick acceptable/unacceptable conversion test for your biodiesel and works because biodiesel will dissolve into methanol while triglycerides do not dissolve in methanol. It works with washed and dried, or unwashed biodiesel that is well settled. Procedure 1. Insure the jar is spotlessly clean and dry. 2. Put 27ml of room temperature (20-22deg C) methanol into the jar. 3. Use the syringe to put exactly 3ml of the room temperature biodiesel under test into the methanol. Biodiesel Lesson 2 page 3

4 4. Put top on Jar. 5. Shake jar hard for 5 seconds. Note: If the biodiesel completely dissolves into the methanol and no biodiesel settles out on the bottom of the container, you have very high conversion biodiesel. 2. The following test items could be used to measure the enabling and terminal objectives on a unit or end-of-level test: 1. In the biodiesel-making process, the step wash biodiesel, which of the following materials was removed? a. glycerin b. soap c. unreacted methanol, MeOH d. unreacted oil 2. In which step does the chemical reaction take place producing biodiesel? a. heat cooking oil b. mix catalyst with MeOH c. mix oil with catalyst and MeOH d. separate biodiesel and glycerin 3. If not followed precisely, which step would result in a slow reaction or a loss of methanol? a. heat cooking oil b. mix oil with catalyst and MeOH c. separate biodiesel and glycerin d. wash biodiesel 4. Methanol boils at what temperature (at sea level)? a F b. 123 F c. 148 F d. 212 F 5. What is a physical property that helps determine if another liquid is water soluble? a. boiling point b. color c. polarity d. specific gravity Biodiesel Lesson 2 page 4

5 6. Which physical property of a liquid relates to that liquid s density? a. boiling point b. color c. polarity d. specific gravity 7. Emulsification of biodiesel in soapy water occurs because a drop of biodiesel becomes surrounded by: a. carbon chain tails b. glycerin c. methanol (MeOH) d. polar heads 8. If cooking oil is only partially reacted, it will fail which test? a. clarity test b. 3/27 test c. safety test d. soap test 9. If the biodiesel is cloudy, it contains: a. glycerin b. excess methanol (MeOH) c. soap d. water Biodiesel Lesson 2 page 5

6 Biodiesel Performance Assessment Name: Date: Unit: Biodiesel Terminal Objective 2: produce biodiesel Performance Objective 2: Given unused cooking oil, necessary equipment and chemicals, produce biodiesel that is free of soap, dry, and ready for testing. Process Evaluation Elements Acceptable Unacceptable 1. Followed safety practices 2. Kept work area clean and neat Product Evaluation Elements Acceptable Unacceptable 3. Soap Test 4. Clarity Test 5. 3/27 Test Note: All items must receive an acceptable rating to pass the objective. Evaluator: Date: Biodiesel Performance Evaluation page 1

7 Activity Sheet 2.1 Making biodiesel Name: Date: 2.1 Directions: Answer the following questions on safety. 1. What safety equipment is used to help keep chemicals out of the eyes? 2. What should be done before leaving the lab to avoid the spread of chemical residues? 3. Why is it important to never taste or touch chemicals? 4. What can be done to avoid inhaling chemical vapor or fumes? 5. To ensure predictable results and maintain a safe environment, what is a good rule to follow? 6. What can be done to avoid contamination of chemical stores? 7. If unsure of how to dispose of a chemical, what should be done? 2.2 Directions: Locate the MSDS notebook in the laboratory and answer the following questions. 1. What should be done if potassium hydroxide enters the eyes? 2. What method should be used to extinguish a fire involving biodiesel? 3. What should not be used to absorb spilled methanol? 4. How should glycerin be stored? Activity Sheet 2.1 page 1

8 2.3 Directions: Match the pictures below with the name from the list by writing the corresponding letter in the space provided. A. hotplate B. funnel C. thermometer D. rocker E. drying pan F. glass Bottle G. separating funnel H. filter paper I. scale J. metal pan K. graduated cylinder Activity Sheet 2.1 page 2

9 2.4 Directions: In the lesson, seven steps have been identified to make biodiesel. From the list of steps below, match the step with its description by writing the corresponding letter in the space provided. A. Mix catalyst with MeOH B. Heat cooking oil C. Mix oil and catalyst/meoh D. Separate biodiesel and glycerin E. Wash biodiesel F. Dry biodiesel G. Filter biodiesel 1. The step in which the chemical reaction occurs. 2. The step to remove any particles in the fuel. 3. The step where glycerin is drained off. 4. The step in which potassium hydroxide and methanol are mixed. 5. The step where cooking oil is heated to speed up the reaction time. 6. The step for removing the water from the biodiesel. 7. The step where soaps are removed. 2.5 Directions: Answer the questions below in the space provided. 1. Why is the cooking oil heated to 138 F and not higher in step 2 Heat cooking oil? 2. What is the difference between a polar molecule and a non-polar molecule? 3. In your own words, what is a specific gravity of a liquid? 4. Draw a simple diagram to illustrate emulsification, or why oil particles (non-polar) might be suspended in water (polar). Include a brief description. Activity Sheet 2.1 page 3

10 Safety Information Sheet for Making Biodiesel Wear splash proof goggles and appropriate gloves Chemicals can splash into the eyes or chemical residue on the hands can be transferred into the eyes if proper precautions are not taken. Also, some chemicals can burn the skin if they come in contact with bare skin. Wear gloves that can withstand the corrosion of chemicals. If gloves rip, remove them, wash and dry your hands thoroughly, and get a new pair of gloves. Always wash your hands before leaving the lab Chemical residues can remain on the skin. These residues can be transferred to other parts of your body and other objects that others, who may be more sensitive to various chemicals, may come in contact. Never taste or touch chemicals Many chemicals are dangerous, even fatal. Even some chemicals that are not dangerous themselves may have been contaminated. Many chemicals can be absorbed through the skin or damage the skin and are, therefore, dangerous to touch. Avoid inhaling fumes The gases that chemical reactions produce can be dangerous or fatal. Always work in a well ventilated area or in some applications, in a fume hood. Always follow directions and never perform an unauthorized experiment Haphazardly combining chemicals can be dangerous or fatal. Do not do anything with chemicals without authorization and instruction from the teacher. Never return unused chemicals to their container This prevents contamination. Secondary containers may have been previously used for another purpose and might have a residue from that purpose. If that residue returns to the original container it could adversely react and spoil the contents of the original container. All unused chemicals that have been taken from their original container should be properly disposed. Dispose of chemicals properly Improper disposal of chemicals is illegal and dangerous. If not properly disposed of, chemicals can have a detrimental affect on health and/or the environment. NOTE: See Material Safety Data Sheets (MSDS) for specifics concerning swallowing, inhalation, contact, and disposal. An MSDS should be kept for each chemical in the laboratory. Safety Information Sheet page 1

11 Safety quiz for making biodiesel Name: Date: Directions: If the item is true, circle the letter T. Otherwise, circle the letter F for false. T F 1. Splash-proof goggles should be worn to keep chemicals out of the eyes. T F 2. Hands should always be washed before leaving the laboratory. T F 3. It is O.K. to taste or touch known chemicals. T F 4. Always work in a well ventilated area. T F 5. It is O.K. to experiment with chemicals in the lab without consulting the teacher as long as it is kept in the lab. T F 6. Unused chemicals should be returned to their original containers. T F 7. If unsure of how to dispose of a chemical, pour it down the drain. Safety Quiz for Making Biodiesel page 1

12 Producing Biodiesel from Cooking Oil Making small quantities of biodiesel will require a little creativity. While the basic process is the same, the equipment 55 gallon drums, pumps, aerators, and heaters will vary. Our primary equipment will be a chemistry separating funnel (250ml), a mixing jar, and miscellaneous components. The chemicals we will use are methanol and potassium hydroxide. The quantity for the chemistry will be a ratio of the following formula: for 1 liter of cooking oil, 220 ml of methanol and 7 10 grams of potassium hydroxide. NOTE: Keep your work area clean. Wash all glass equipment with soap and brushes and rinse thoroughly. Step 1 Step 2 Mix Catalyst with MeOH The first step is to make the catalyst. Weigh 1 gram of potassium hydroxide flakes and place in the bottom of your mixing bottle. Measure 25ml of methanol and pour into the mixing bottle with the potassium hydroxide. Mix the chemicals by shaking vigorously until the potassium hydroxide is completely dissolved into the solution. Heat Oil Heat 110ml of cooking oil to 138ºF. NOTE: The boiling point of Methanol is approximately 148ºF at sea level. Step 3 Mix Oil and Catalyst/MeOH Add the heated cooking oil slowly and carefully to the methanol and potassium hydroxide solution. Mix the ingredients by shaking vigorously for 3 to 5 minutes. Pour the solution into a separating funnel. Allow time for the reaction and separation of the solution. It is advisable to allow the solution to set overnight. Step 4 Separate Biodiesel and Glycerin Separate the glycerin from the biodiesel by draining it out of the bottom of the separating funnel. Set the glycerin aside in a common container for later use in making soap. There will be two distinct and separate layers after the reaction and separation is complete. The solution on the bottom will be glycerin with any methanol not used in the reaction. The solution on top will be biodiesel with soaps that will need to be removed. Biodiesel Lesson 2 Help Sheet page 1

13 Step 5 Step 6 Step 7 Wash Biodiesel It is now time to wash the biodiesel to remove soaps. Gently pour 30ml to 40ml of warm water into the separating funnel. With the separating funnel held on its side, gently rock the funnel back and forth allowing the water to mix with the biodiesel. WARNING: Too rigorous of a washing motion will create an emulsion (mayonnaise-like material) that will take days or weeks to break down and dissolve not good. The soaps in the biodiesel will defuse into the water turning it milky white. Continue the washing motion for 3 to 5 minutes. After washing, let the solution set in the separating funnel for 5 to 30 minutes and then drain off the water solution. Repeat the process for 4 to 6 washings or until the water separating out is clear. With each washing, the rigor of the wash can slowly increase. If time and sharing of equipment allows, let your last wash and drain sit overnight for any additional separation. Dry Biodiesel After washing the biodiesel, it is necessary to dry it removing any water that is now in solution. We will evaporate the moisture from the biodiesel. Agitation, heat, and air movement all assist and accelerate the process. Due to the small quantity of biodiesel we are making, traditional methods with heaters, pumps and/or aerators are problematic. We will simply agitate our solution in a shallow pan using a rocker platform. The biodiesel will become clear after the water is removed. A simple test is to place newsprint on the back side of a bottle of biodiesel. If you can read the print, the biodiesel is clear and free of water. Another test is to collect a small sample of biodiesel from your batch and heat it to 212ºF, the temperature of boiling water, and observe if any bubbles form. If no bubbles form at 212ºF, the solution is free of water. Discard this sample, and conclude your batch is dry of water. Filter Biodiesel For our application, we will filter the biodiesel to ensure clean operation in our diesel engine. Filter paper, 125mm in diameter, should be folded to form a cone with no opening in the bottom similar in shape to the glass funnel supplied. After placing the filter paper inside the funnel, pour your biodiesel slowly into the funnel so it must pass through the filter paper. Avoid pouring the biodiesel in the funnel so the fuel passes above and around the filter paper. This set up can be used by several groups to save time and filter paper. Biodiesel Lesson 2 Help Sheet page 2