Life Cycle Assessment (LCA) Class Notes, Activity Adam Kiefer General Overview: A life cycle assessment (Life Cycle Analysis, LCA) is an evaluation of a consumer product’s environmental impact over the entire life of the product. This means that we are not concerned about the waste generated by one application of a product, rather we are concerned with the production, use, and fate of a product. Part I: Powerpoint Presentation / Intro to the LCA NOTE: You are free to use the .ppt slides provided with this case study. The instructor may be better off coming up with their own presentation using some or all of the slides provided. Using the powerpoint presentation associated with this activity, students will be introduced to the general concepts of a qualitative pictorial life cycle analysis of a variety of items, including an automobile and EtOH based biofuels. The key thing to remember is that LCAs are very detailed, and often contain a lot of math. Students should walk away from this exercise with a purely qualitative understanding of the LCA. Similarly, students should recognize the complexities of manufacturing, use and disposal. Part II: The Toothbrush, Construction of the LCA. Goal: To reinforce the students understanding of how even a simple item plays a complex role in consuming non-renewable resources. Lesson Plan: Pass around a few identical toothbrushes in its original packaging, including the price. While students are laughing at you because you have assumed they have never seen a toothbrush before, you should encourage them to notice the fine details of the toothbrush that they perhaps had not noticed before. Also, on the board, write up the three major stages of the life cycle: Manufacture, Use, and Disposal. Write each of these 3-5 ft. apart on the board in an oval. If you don’t leave enough space early on, this project will become illegible: After everyone has seen the toothbrush, tell students that the class has been hired to do a qualitative life cycle analysis to determine the environmental impact of the toothbrush on American society. Start off with the easiest component of the LCA, use. Ask students what input does the average person use to operate a toothbrush. (Water, toothpaste, etc.). What are the byproducts of the usage of a toothbrush? You can make this answer as simple or complex as you want. I always include wastewater. I will include biological waste (saliva, bacteria, virus) as well as chemical waste (fluoride, artificial coloring). Creating a flow chart allows students to see the process as it “occurs”. Also Show the direct connection (fossil fuels) between Manufacture, Use and Disposal/Recycling/Reuse. At this point, your flow chart should look something like this: Explain to students that an LCA is a living thing, and we will be able to come back to the “use” category later. Now concentrate on Disposal/Recycling/Reuse. Disposal is relatively easy. We take the toothbrush and throw it in the trash. Students often realize that the toothbrush goes to a dump and takes up space for a very long time. A few exceptional students may recognize that eventually the toothbrush will decompose to CO2 ( a greenhouse gas) after hundreds of years, but I wouldn’t count on it. There is a difference between reuse and recycling. Recycling is where the product has a series of operations performed on it, so that it can be reused either for its original intention ( a toothbrush) or a new process (a soda/pop bottle). In this case suggest to the student that you could bleach or boil the toothbrush to sterilize it, thus recycling it for use as a toothbrush. Recycling regenerates the “cycle” by directly reconnecting “Disposal/Recycling/Reuse” with “Use”. Reusing (in this case) indicates that the object is used as is for an alternative purpose. A toothbrush can be used as a cleaning utensil. Your diagram should look like this: Aside: Students often have trouble distinguishing between reusing and recycling. Stress that reusing is often the result of no external influence and it implies that the product remains relatively unchanged. For example, a tire that has a hole in it can be reused as a tire swing, or cut into strips and made into the soles of shoes. This is considered reusing. Recycling often has some external influence on it, such as sterilization, or melting. Carpet can be recycled by chemically breaking it down into its starting materials, and then remaking the carpet from these materials. More and more often these terms are being used interchangeably. And now on to the most difficult component of the LCA, manufacture. Begin by asking the students to describe what components make up the toothbrush. A student will often volunteer the word plastic. In this case, ask the students how many types of plastic comprise the toothbrush. Typically, the bristles are different than the rubbery handle, the hard composite stem, and the clear packaging plastic. Ask the students if they believe that these plastics are produced where the toothbrushes are made. If not, where do the starting materials come from (petroleum). At this point students should realize that the manufacturing component is quite extensive. Questions the instructor can ask to spur conversation: 1) Do you think plastic is naturally white, blue or red, or are dyes required. 2) 2) Lets look at the packaging which we discard prior to using the toothbrush. What is it made from (paper, ink, dyes adhesives) 3) How do these components get from the factory to the toothbrush factory LCA should look something like this: What happens if the price of crude oil increases? Remember, this is a crude outline… your students may come up with things that I’ve not even thought of. Student Activity: Break students into groups of ~4 students. Give each group $3.00 (either real or imaginary) and tell them to purchase an item from the student union / bookstore. The item may not have moving parts or be mechanical… keep it as simple as possible. A quick word of advice/warning: students love to purchase food. Food LCAs can be quite extensive, but offer students a chance to figure out where each ingredient comes from (the field or the factory). I like allowing the students to purchase their own item, but logistically it might be easiest to bring in a number of inexpensive items. In class give the students ~ 5 minutes to sketch out an LCA for the item. This should give you enough time to determine if they are on the correct path. On a piece of posterboard or a .ppt presentation, have students present to the class a 2-4 minute presentation laying out an LCA for their product. Make sure it is abundantly clear that each student in the group must present some aspect of the LCA, and students must discuss why they purchased the item.
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