activity 5 Section 1. Gathering Information Case Study Jigsaw

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1 Section 1. Gathering Information Case Study Jigsaw Summary Using this cooperative learning technique, each student will share information on various facilities, operations, and industries in the Southeast that use woody biomass for energy and learn about wood to energy conversion technologies. activity 5 n Subjects Science, Language Arts n Key Questions 1. How is energy extracted from wood? 2. How is woody biomass used to produce energy? 3. What facilities, operations, or industries in the Southeast use wood for energy? Background Woody biomass is plant material from trees and shrubs and can include roots, bark, leaves, branches, limbs, trunks, and vines. Where does woody biomass come from? Woody biomass can come from many sources. These sources include residues from forestry operations and industries that make products out of wood, such as paper or furniture; tree and shrub trimmings from urban areas; forest thinning; and trees grown for energy. Residues When trees are harvested, branches, tree tops, stumps, and other debris are left behind on the forest floor. These residues can be collected and used for energy production. Another type of residue is generated by furniture and other wood-product industries in the form of sawdust, scraps, and chips. Often, wood-product facilities use their own wood waste to produce heat, steam, or electricity for powering their equipment and machinery. n Objectives By the end of the activity, students will be able to do the following: 1. Synthesize information about various facilities, operations, and industries in the Southeast that use woody biomass for energy (LA ). 2. Use oral communication skills to present information to classmates (LA ). 3. Consider various benefits and challenges to using woody biomass for energy (SC.912.L.17.11). n Materials Copies of Case Study Information Cards or copies of full-length case studies for each student. Copies of Group Worksheet and Student Worksheet for each student n Time Estimate 50 minutes to1.5 hour (Time will vary depending on whether you choose to have a class discussion at end of activity and whether you use of shortened cards or fulllength case studies.) Should We Use Wood for Energy? Section 1 Activity 5: Case Study Jigsaw 59

2 Woody biomass from urban waste wood can be used to produce energy and can also be a good way to dispose of these materials while reducing the pollution causing emissions. Urban Waste Wood As you travel though your community, you might see piles of debris and yard waste along the street. This woody biomass is a potential energy resource and is the cheapest of the woody biomass options. Similarly, the material generated when utility companies trim tree limbs and branches from power lines can be used. In addition, when land is cleared for development or a storm damages trees, woody biomass is produced. To dispose of urban waste wood, materials are often mulched, taken to a landfill, or burned without emission controls. Woody biomass from urban waste wood can be used to produce energy and can also be a good way to dispose of these materials while reducing the pollution causing emissions. Forest Thinning To improve forest health and productivity, foresters and landowners often remove some trees and vegetation. This reduces crowding in the forest and allows the remaining trees to get more sunlight and nutrients. Removing smaller trees in the understory of a forest reduces the risk of wildfire and damage from outbreaks of insects or disease. This removed biomass could be a source of biomass for energy. Trees Grown for Energy Just as trees are grown to produce lumber, paper, and other products, trees can be grown for energy. In the southeastern U.S., pine and hardwood plantations are a possible source of woody biomass for energy production. Some species of trees or woody plants, known as short-rotation woody crops, grow very quickly. Some hardwood species, such as eucalyptus and willow trees, can resprout after they are cut. These crops produce a lot of biomass in a short period of time and can be harvested numerous times before being replanted. In addition, some trees are planted for phytoremediation whereby the trees take up and use pollutants in the soil as nutrients. Phytoremediation can be used to clean up sites that have contaminated soil or water. This can be a good use of degraded lands that cannot be used to grow food crops. Trees grown on these sites can be removed and used for energy. Woody biomass from urban waste wood and storm debris can be used to produce energy. Pine plantations in the southeastern U.S. represent another possible source of woody biomass. Short rotation woody crops grow fast! The eucalyptus trees pictured here are only two years old! LARRY KORHNAK LARRY KORHNAK martha monroe 60 Should We Use Wood for Energy? Section 1 Activity 5: Case Study Jigsaw

3 Generating Energy from Wood: Conversion Technologies There are a variety of technologies that can transform wood into energy for residential, commercial, and industrial uses. Wood to energy systems can produce anywhere from less than 1 megawatt (MW) to more than 100 MW of power and can use wood exclusively or in combination with other fuels, such as coal or natural gas. This energy can be used to generate electricity; heat buildings with water, steam, or air (space heat); produce steam for industrial processes; or power vehicles and machinery. All of the processes involve breaking down the cellulose in wood to release the energy it contains. thick or wide; wood pellets, made from compressed saw dust, range from 5 to 30 mm long; and saw dust is the smallest at 1 to 5 mm (FAO, 2004). Different systems use different forms of wood including split wood fuel (traditional firewood), whole trees, wood chips, wood pellets, waste wood from making forest products, and charcoal briquettes. Some of the wood-burning units can also use other types of fuel, such as oil or natural gas in combination with wood, or electricity from the power grid. Wood can also be burned to produce heat using woodstoves, fireplaces, pellet stoves, or boiler systems. These systems can be located inside or outside buildings. NATIONAL RENEWABLE ENERGY LABORATORY Using Wood in its Solid Form The simplest way to obtain energy from wood is to burn it. This is called direct combustion. The resulting energy can provide power, electricity, or heat. To produce power, wood can be burned in a large combustion chamber (often called a boiler) to heat water that generates steam. In some cases, this steam is used directly to power machines or to heat buildings. Some schools, for example, run steam through a system of pipes to heat classrooms. Some hospitals also burn wood to produce steam for sterilizing equipment and powering machines. In addition, steam can be used to turn large, rotating engines called turbines, which generate electricity. This electricity can be used onsite by industries to power machinery or can be sold to the power grid. Some facilities do both steam first turns a turbine and then is used for heat. This is called co-generation because two forms of energy are generated from one process. When wood is used in power plants, it can be burned alone or in combination with coal or other fuels. Burning two fuels together is called co-firing. Because it is more efficient to burn wood pieces that are the same size and have similar moisture content, most facilities use wood chips, wood pellets, or saw dust. Wood chips tend to be 5 to 50 millimeters (mm) long and longer than they are In this boiler, wood is burned to heat water and generate steam. Most facilities use wood particles of consistent size, such as wood chips. Wood-burning stoves provide a source of heat for homes. martha monroe NATIONAL RENEWABLE ENERGY LABORATORY LAUREN MCDONELL Many technologies are available to transform woody biomass into energy. Should We Use Wood for Energy? Section 1 Activity 5: Case Study Jigsaw 61

4 Thanks to relatively new technological breakthroughs, woody biomass can provide the substances needed to manufacture renewable diesel fuels on a larger scale. Converting Wood into Biogas Woody biomass can be converted into gas, called biogas, using one of two methods: 1. Gasification exposes wood to extremely high temperatures (900 to 1,200 C) and pressure in a low oxygen environment. As gas is produced, some liquids are also produced. 2. Anaerobic digestion exposes wood to bacteria in the absence of oxygen. In both processes, a gas is produced as the cellulose is broken down. This biogas can be used like natural gas for cooking, heating water or buildings, or producing electricity. Heating wood in the absence of oxygen creates liquid oil. Converting Wood into Liquid Oil Wood can be made into a type of liquid oil, called bio-oil, by heating it quickly to a high temperature in the absence of oxygen. This process is called pyrolysis. In addition to producing liquid oil, this process produces char and a combustible gas. Bio-oil can be burned in boilers to heat buildings or in generators to produce electricity. Since the oil contains a much higher amount of energy per unit volume than wood, it is easier and cheaper to transport than wood. The pyrolysis gas, as mentioned earlier, can be used much like natural gas. The char can be processed for a variety of uses including briquettes for grilling, purifying metals, and as an additive to fertilizer. Converting Wood into Transportation Fuels Wood can be used to produce transportation fuels, such as ethanol, methanol, or biodiesel. Ethanol is produced through a process called fermentation in which wood is exposed to microorganisms. As these NATIONAL RENEWABLE ENERGY LABORATORY microorganisms decompose the wood, enzymes are produced. These enzymes trigger a chemical reaction that exposes and breaks down the sugars in the wood. Certain microbes can then be added to the sugar solutions to convert them into ethanol, a colorless alcohol, and other byproducts. Once processed, ethanol can be used in combination with gasoline to make E-10 or E-85 to power vehicles equipped to burn it. E-10 contains 90 percent gasoline and 10 percent ethanol and can be used in most modern vehicles; E-85 contains 15 percent gasoline and 85 percent ethanol and can be used in engines modified to run on higher concentrations of ethanol, such as flexiblefuel vehicles. Research is progressing quickly to make this process feasible on a large scale. Another liquid, called methanol, can be produced from woody biomass. As already mentioned, when woody biomass is gasified, the resulting gas can be converted to a liquid. This is one method of producing methanol. Methanol can be used to fuel vehicles or to produce other chemical products. Currently, most methanol is produced using natural gas. Additionally, biodiesel is a liquid fuel that can be used to power machinery and vehicles. In a process called alcoholysis, oils extracted from wood are combined with alcohol and a catalyst to produce a renewable fuel diesel fuel. Thanks to relatively new technological breakthroughs, woody biomass can provide the substances needed to manufacture renewable diesel fuels on a larger scale. Biomass can be used to produce transportation fuels. NATIONAL RENEWABLE ENERGY LABORATORY 62 Should We Use Wood for Energy? Section 1 Activity 5: Case Study Jigsaw

5 Teacher Instructions teacher Preparation 1. It is highly recommended that students complete Activity 3: Biomass Basics Web-quest prior to doing this activity. 2. This activity can be completed using either the provided Case Study Information Cards or the full-length case studies (available in the Supplemental Reading section). The fulllength case studies provide additional details about the facilities and require more time for students to read, analyze, and present the information. 3. Read the Background Information, and if desired, make copies of background information for students to read prior to completing the activity. 4. Make copies of either the Case Study Information Cards or the full-length case studies for each student (use one case study per group). 5. Make copies of the Group Worksheet and Student Worksheet for each student. Procedure 1. If you are assigning students to read the Background Information before completing the activity, ask them to read it for homework. 2. Give each group enough copies of one case study for each student to have one, and give each student a copy of the Group Worksheet and Student Worksheet. 3. Explain to the groups that they will be investigating various case studies about facilities, operations, or industries in the Southeast that use woody biomass for energy, heat, power, and/or electricity. 4. If using the Case Study Information Cards, tell groups to select one member to read the card aloud to the group. After reading, groups should complete the Group Worksheet (each student should complete his or her own worksheet). If using the full-length case studies, each student should read the case study, discuss as a group, and complete the Group Worksheet. When the worksheet is completed, students should review their responses as a group. 5. Next, form new groups using a jigsaw technique. Take one student from each existing group to make new groups, each containing six students. Each new group should have at least one student representing a different case study. 6. In the new groups, allow every student a couple of minutes to discuss the information they learned from their case study. Depending on the number of students in class, some groups may have more than one member representing the same case study. If this occurs, instruct students to split up the explanation of their case study. 7. To summarize the activity and reflect upon what they have learned, ask students to complete the Student Worksheet. This can be completed in class as a group or individually, or for homework. If time permits, initiate a class discussion regarding the answers to the Student Worksheet. Resources Additional case studies available on the InterfaceSouth Web site: The Case Study Information Cards have been adapted from the following Wood to Energy case studies (available in the Supplemental Reading section): Berg, J. E., Villegas, A., & Monroe, M.C. (2007). Wood to energy case study: Forest industry creates its own power. Gainesville, FL: University of Florida IFAS Cooperative Extension Service. Cannon, L. & Monroe, M.C. (2007). Wood to energy case study: Converting from natural gas to waste wood. Gainesville, FL: University of Florida IFAS Cooperative Extension Service. McConnell, L. & Monroe, M.C. (2007). Wood to energy case study: Using a mix of fuels to produce heat and power. Gainesville, FL: University of Florida IFAS Cooperative Extension Service. McConnell, L. & Monroe, M.C. (2007). Wood to energy case study: Wood and paper trim the energy bill. Gainesville, FL: University of Florida IFAS Cooperative Extension Service. O Leary J. E. & Monroe, M.C. (2007). Wood to energy case study: Co-firing with wood and switchgrass. Gainesville, FL: University of Florida IFAS Cooperative Extension Service. O Leary J. E. & Monroe, M.C. (2007). Wood to energy case study: Wood power heats a public school. Gainesville, FL: University of Florida IFAS Cooperative Extension Service. Assessment Suggestions Objective 1: Review student answers to Student Worksheet, particularly questions 1 and 2. Objective 2: Each student must present their case study information to new groups. Walk around as students share information. If you opt to do the first extension idea below, students can also be assessed on oral presentations of their posters to the class. Objective 3: Review student answers to Student Worksheet, particularly questions 3 and 4. Extensions Ask students to research another example of a facility that uses wood for energy, make a poster, and present this information to the class. Sample rubrics for grading posters can be found at: rubistar.4teachers.org/ index.php Take a field trip to one of the case study locations or take a field trip to an energy facility that uses biomass for energy. Call your local utility for more information. Should We Use Wood for Energy? Section 1 Activity 5: Case Study Jigsaw 63

6 STUDENT Case Study Jigsaw Group Worksheet NAME date period After you have read your case study, work as a group to answer the following questions. Review your answers as a group. When you rotate groups, you will share this information with new group members. 1. What is the name of the facility? 2. Where is this facility located? 3. What sources of biomass does this facility use? 4. Explain how energy is produced at this facility. 64 Should We Use Wood for Energy? Section 1 Activity 5: Case Study Jigsaw

7 Case Study Jigsaw Student Worksheet STUDENT NAME date period Answer these questions after you ve completed the second group activity. Be prepared to share your information with the class. 1. List at least five different types of woody biomass that can be used for energy. 2. Describe three different ways that these facilities use the energy they produce from woody biomass. 3. How do the facilities benefit from using wood for energy? 4. On the other hand, can you think of possible disadvantages of using wood for energy that were not mentioned in the case studies? Should We Use Wood for Energy? Section 1 Activity 5: Case Study Jigsaw 65

8 STUDENT Case Study Jigsaw Case Study Information Cards (1 of 3) n Co-firing with Wood and Sugarcane Waste The Okeelanta Cogeneration Facility, near Lake Okeechobee, Florida, is the nation s largest woody biomass power plant. While there are no forests near this power plant, there are 168,000 acres of sugarcane, which is processed at a sugar mill next to the power plant. During sugar processing season (October through March), the Florida Crystals Sugar mill makes two-thirds of the power plant s needed fuel by using bagasse, the fibrous residue leftover from squeezing juice out of sugar cane. The bagasse is mixed with wood chips to improve the quality of the fuel. When it is not processing season, a greater percentage of wood is used because bagasse cannot be stored for long periods of time. The wood chips are purchased and transported from land clearing and urban tree trimming activities across south Florida. The first priority of the power plant is to produce steam power to run the sugar mill during sugar cane processing season. The power plant is permitted to generate 140 megawatts of additional electricity year round, which is sold to the power grid. n Converting from Natural Gas to Waste Wood Laurel Lumber is a privately owned company in Mississippi that has been in business for more than 30 years. The company operates a remanufacturing plant that specializes in drying and dressing one-inch boards from southern yellow pine. Until five years ago, the plant relied upon natural gas to directly heat its kilns, where the wood is dried. Due to the high cost of fuel, we needed to find a cheaper way of drying the lumber, says Plant Manager Patsy Brown. We were also having a problem with the buildup of wood waste. A biomass energy program provided solutions to both of these problems. In 2004, Laurel Lumber installed a steam boiler, which allows the plant to use waste wood (wood byproducts from processing) as fuel to heat the kilns. While the initial installation of the boiler and piping systems was expensive, the biomass program saves Laurel Lumber approximately $200,000 in production costs each year. The Okeelanta Cogeneration Facility produces steam power to run Florida Crystal s largest sugar mill and sells surplus energy to the power grid. Woody biomass provided Laurel Lumber with lower energy costs than natural gas. LAUREL LUMBER MARTHA C. MONROE 66 Should We Use Wood for Energy? Section 1 Activity 5: Case Study Jigsaw

9 Case Study Jigsaw Case Study Information Cards (2 of 3) STUDENT n Forest Industry Creates Its Own Power In addition to growing timber, the Langdale Company also harvests, processes, and produces various wood products. At their Langboard OSB (oriented strand board) mill in Quitman, Georgia, the company has one of the first co-generation power plants at an engineered or solid wood facility in the southeastern United States. Co-generation means that the facility uses one type of fuel, woody biomass, to produce heat and steam for operating the OSB mill and produces electricity at the same time. Established in January 2006, the cogeneration plant produces up to 12 megawatts of power by using the excess heat and steam from the combustion of biomass sources. This electricity is transmitted directly onto the energy grid. Fuel types used in the co-generation plant include mill residues (bark, shavings, dust) and chipped logging residues and understory materials). A significant amount of fuel is also produced at the facility as a by-product of the OSB manufacturing process. The Langdale Company is the only fossil-fuel independent OSB mill in the United States, an important milestone for sustainable energy. Langdale industries produces a wide variety of forest products including utility poles. n Using a Mix of Fuels to Produce Heat and Power About five miles outside of New Bern, North Carolina, a biomassfueled power plant supplies the electrical grid system with 50 megawatts of energy daily. Craven County Wood Energy was constructed in The facility uses approximately 500,000 tons of waste wood per year. Ten percent of fuel is railroad ties, six percent is wood shavings from poultry brooder houses, and the remainder is wood waste from forest thinning, pallets, land-clearing debris, harvest residues, sawmills, and clean urban waste wood. Much of the wood used at Craven County Wood Energy would have ended up in county landfills. Instead, the facility uses the woody biomass to supply energy to nearby communities, reducing the demand for fossil fuel resources. Twenty-six people are employed at the facility, and approximately seventy-five more work indirectly to meet fuel production and transportation needs. Craven County Wood Energy supplies 50 megawatts of power each day by using woody biomass as a fuel source. Should We Use Wood for Energy? Section 1 Activity 5: Case Study Jigsaw 67

10 STUDENT Case Study Jigsaw Case Study Information Cards (3 of 3) n Wood and Paper Trim the Energy Bill In the 1970s, when energy prices began to rise, Northwest Missouri State University, in Maryville, Missouri, started searching for alternative fuel sources to heat and cool campus buildings. The university decided to use wood chips, a by-product of the local forest products industry. Currently, at Northwest Missouri State University, wood provides 65 percent of the thermal energy needed to heat 1.7 million square feet of building space and also provides some energy for cooling. By using local wood resources, the university has saved more than $375,000 per year for the past 20 years. In addition to using wood chips for energy, the facility also produces energy from paper! After a pilot study, the university learned that discarded newspapers, magazines, and cardboard could be burned to produce energy at the campus biomass plant. The Maryville local government encourages residents to separate recyclables from their trash, and the clean paper waste is delivered to the university. Because the wood-fueled facility was able to help the community achieve waste reduction goals, the university received the 4th Annual Governor s Pollution Prevention Award in n Wood Power Heats a Public School For more than 25 years, Rowan County High School in Morehead, Kentucky, has been using wood to produce heat for its buildings. Wood was chosen as a fuel source because it was locally available and offered a reliable source of energy. The school s sawdust combustion unit was installed in The combustion unit can generate a maximum energy output of 0.15 thermal megawatts. This unit generates enough energy to heat the high school buildings and a nearby vocational technical institute. One-third of the steam output produced by the unit is sold to Rowan Technical College to meet its utility needs at a cost comparable to using natural gas. The combustion unit burns nearly 756 tons of pure sawdust each year, which is supplied by local lumberyards. The school saves an estimated $21,000 per year because of its woody biomass combustion unit. Northwest Missouri State University is located in Maryville, Missouri and has a student population of more than 6,500. The high school s wood to energy facility provides a market for local sawdust. CREATIVE COMMONS ATTRIBUTION SHARE ALIKE 2.5 MISSISSIPPI ALTERNATIVE ENERGY ENTERPRISE. 68 Should We Use Wood for Energy? Section 1 Activity 5: Case Study Jigsaw