Biology

Biofuels: Can plants power the Earth? This lesson will investigate the use of biofuels as an alternative source of energy. We will look at questions such as: • What are biofuels? • Are biofuels an efficient source of energy? • What are the benefits and drawbacks of switching to biofuels? • What is the future of biofuels? This lesson will fuel your interest in alternative energy.

This is a print version of an interactive online lesson. To sign up for the real thing or for curriculum details about the lesson go to www.cosmosforschools.com

Introduction: Biofuels (P1)

Biofuels are fuels made from recently living things, like plants. Many people think of them as a better alternative to fossil fuels, such as coal and petrol. When coal and petrol are burned to produce energy they release a lot of carbon dioxide gas into the atmosphere, which helps heat up the Earth. The biofuel alternative seems simple. Plants can be made into fuels, and can be grown again and again. But a climate scientist at Monash University decided to add up all the energy needed to grow the plants to see if the sums really made sense. His results show the answer is not that simple. The problem is that photosynthesis - the process by which plants turn energy from the Sun into usable energy - isn't very efficient. So you need many, many plants to produce the same amount of energy as a small amount of fossil fuel. For example, if you turned all of the wheat grown in Australia into biofuel (that's roughly 30,000,000 tonnes of wheat every year), you would only produce about 4% of the energy the country uses. It not only takes a lot of energy to grow the plants, it also takes away land that could be used to grow food. And what's maybe worse, we would have to cut down more forests to provide the land to grow the plants to drive our cities.

Read the full Cosmos Magazine article h ​ ere

Left: Rapeseed is grown for its oil, which can then be used as a biodiesel. Right: The 'Algaeus' is a hybrid car that is fueled by an algae-derived diesel. Sources: iStock and Algae Industry Magazine

Question 1 Biofuel is a compound word, that is, a word that is made up of two or more other words. Bio means life and a fuel is a material that can be burned to produce heat or power. A biofuel is a material derived from recently living matter that can be burned to produce heat or power. In contrast, a fossil fuel is a material derived from matter that lived millions of years ago that can be burned to produce heat or power. Reflect: Complete the following table. The first row has been completed for you. Material Wood Sunflower seed oil Dry cow dung Steel wool Diesel extracted from algae Orange juice

Derived from recently living matter? yes

Can be burned to produce heat or Seems like it could be a power? biofuel? yes

yes

Gather: Biofuels (P1)

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Source: YouTube

Question 1 ​Recall: Biofuels originally come from organic matter. True or false?

Question 2 Recall: In the transport sector, what percentage of energy consumption is the EU aiming to have coming from renewable sources by the year 2020?

True 5 False 10 20

50

Question 3 Define: What are biofuels?

Question 4 Describe: Drawing from the information in the video, complete the table below. Definition First generation biofuel Second generation biofuel

Sources: iStock & Chappatte in "International Herald Tribune".

Question 5 Identify: What are some of the advantages of using first generation biofuels?

Question 6 Identify: What are some of the disadvantages of using first generation biofuels?

Examples

Process: Biofuels (P1)

Left: This illustration shows how much sugar cane and wheat farmland is required to generate the same amount of energy as a standard coal-fired power plant. Right: Harvesting wheat. Source: Graeme Pearman & wheat image caption Source: iStock

Question 1 Calculate: How much more farmland is required to grow wheat compared to sugar cane to produce the same amount of energy?

Question 2 Compare: Place the numbers 1-7 in the appropriate section of the Venn diagram below comparing renewable energy resources with non-renewable energy resources. Once you have finished you can write in a few examples of your own. 1. Examples include coal, crude oil and natural gas. 2. Cannot easily be replenished. 3. Used to generate electricity. 4. Are naturally or easily replenished. 5. Is the energy type used to power most aeroplanes. 6. Are generally more environmentally friendly as they are not permanently removed from the environment. 7. Examples include solar, geothermal, wind, tidal and biofuels.

Watch the following mythbuster video showing Jamie and Adam trying to find out if vegetable oil will run a car as efficiently as diesel and then respond to the questions below. Loading

Question 3 Distinguish: What was Jamie and Adam's research question and aim?

Question 4 Explain: Was their experiment valid, that is, was it a fair test because they controlled their variables? Identify at least two variables that were either controlled, or not, when giving your response.

Question 5 Evaluate: It is important for scientists to repeat their experiments to find out if their results are consistently similar. If the results are similar each time they can then say that their results are reliable. Are Jamie and Adam's results reliable? Why or why not?

Question 6 Design: Draw a table in the project space below that Jamie and Adam could use to collect their data. When you have finished, add in their data to your table.

Question 7 Reason: What are some pros and cons of using vegetable oil to fuel car engines?

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Question 8 Analyse: Who made this video? Do you think that the video shows a balanced view on biofuels? Why or why not?

Question 9 Infer: At the end of the video the narrator makes a plea to stop the use of 'bad' biofuels? Using an example in the video, what do you think they mean when they say 'bad' biofuels, and why would they think they were 'bad'?

Question 10 Contrast: Do you think there are 'good' biofuels? If there are, what would make them 'good'?

Apply: Biofuels (P2)

Biofuel SWOT Analysis

Sources: iStock & Michael Ramirez Creators Syndicate: Auspac Media.

A SWOT analysis is a useful tool to use to examine a controversial issue because it allows you to consider all the positive and negative points together. SWOT stands for: Strengths - here you can collate all the advantages biofuel has over other fuels in the fuel or energy industry Weaknesses - here you can write all the disadvantages of biofuels in relation to other fuels in the fuel or energy industry Opportunities - here you consider where biofuels could be useful in other ways, such as to help the environment Threats - for this you can write how biofuels could be harmful to others and/or the environment In summary: Strengths and Opportunities are both positive ideas, while Weaknesses and Threats are negative points. Strengths and Weaknesses are factors that are internal, that is related directly to the biofuel industry, while Opportunities and Threats are factors that are external to the biofuel industry, such as those related to the environment. Use the ideas you have already considered when completing this lesson on biofuels, as well as additional research from the internet or any science journals that you may have available at your school library. When you have included as many ideas as you can, the SWOT analysis will help you decide whether the overall impact of your chosen biofuel will be positive or negative.

Question 1 When carrying out your SWOT analysis you are to focus on a specific type of biofuel. Examples that you could choose include bioethanol, biogas or biodeisel. Write here what type of biofuel you are going to complete your SWOT analysis on:

Question 2 In order to complete the SWOT analysis, write your ideas and researched information in the boxes provided under the headings strengths, weaknesses, opportunities and threats. Refer to the explanations above to help you decide where different examples and ideas should go in the SWOT analysis. If you need more information on how to carry out a SWOT analysis, there are plenty of websites that can help you - just perform an internet search for 'SWOT analysis'. Positive

Negative

Internal (fuel, energy industry)

Strengths

Weaknesses

External (environment, other industries, individuals)

Opportunities

Threats

Question 3 Imagine that you have been asked to give your opinion about the future of the biofuel you examined in your SWOT analysis. Using the ideas you collated in the four different boxes above, write a few sentences to summarise your opinion about whether or not your chosen biofuel has a future as an alternative renewable energy source.

Careers: Biofuels (P2)

Julia Cremer is a young molecular biologist at the University of Queensland in Brisbane, who studies the proteins inside plants. She hopes to develop a super-crop that can survive climate change and be used for both food and biofuel.

If you ate cereal or toast for breakfast this morning then you have already eaten food made from wheat, rice, or corn. These are some of the most common crops grown in Australia. Unfortunately these crops are not very tolerant of the extreme and erratic weather that climate change will bring, such as droughts and floods. It is less likely that you have eaten food made from the crop that Julia Cremer works with - sorghum. Sorghum originated in Africa, and it is very good at surviving extreme weather. The problem is that sorghum is difficult for humans to digest and is expensive to process into biofuel. Julia is working to fix this by looking at the proteins in sorghum grain to see if she can create a new variety that is both easier to digest and can be converted to bioethanol. One of the best things about Julia's work is that every day is different. One day she might be in the lab doing experiments, and the next she can be outside in the sunshine visiting farms and chatting with farmers. She says that her field of molecular biology is "constantly evolving and there is always something interesting to learn". Julia has nearly finished her PhD - one of the final stages of university. She is currently very busy writing her PhD thesis, which is like an essay only 80,000 words long! A typical day for Julia involves riding her bike, working on her thesis, and going to the gym. But she still makes time to do the other things. She loves going to the beach, camping, traveling, taking dance classes and going to music festivals.

Question 1 ​Enquire: Imagine you are a science journalist. If you were to ask Julia two questions about the use of sorghum as a biofuel, what would they be?

Cosmos Lessons team Education Editor: Bill Condie Art director: Robyn Adderly Profile author: Edwina Berry Lesson authors: Sally Parker and Daniel Pikler