)) was measured with a piece of ribbon and a ruler.

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2 Abstract Fossil fuels are running out and we need to find an alternative. Many countries produce sugar which can be converted into ethanol. Therefore, the aim of this study was to find out which sugar produced the most amount of ethanol. Yeast and the sugar solution (fructose, sucrose, glucose, xylitol and coconut sugar) was added to a bottle and the bottle was shaken. A balloon was placed on top of the bottle. The bottles were allowed to stand for one hour. The balloon s circumference (which filled with carbon dioxide (CO 2 )) was measured with a piece of ribbon and a ruler. The average of the three balloons was recorded. The results were fructose (60 cm), sucrose (53.7 cm), glucose (57 cm), xylitol (0 cm) and coconut sugar (63.3 cm). The xylitol did not produce any ethanol because it is a sugar alcohol which cannot be fermented. Thus, coconut sugar produced the most amount of ethanol and can be used as a potential future source of renewable energy for fuel. 2

3 Some definitions Anaerobic: relating to or requiring no free oxygen. Coconut sugar: a sugar produced from the sap of cut flower buds of the coconut palm. Controlled variable: one element that is not changed throughout an experiment. Dependent variable: a variable (often denoted by y) whose value depends on that of another. Fermentation: the chemical breakdown of a substance (e.g. sugar) by bacteria, yeasts or other microorganisms, to produce acids, alcohols or gases, typically involving effervescence and the giving off of heat. Fructose: a sugar of the hexose class found especially in honey and fruit. Glucose: a simple hexose sugar which is an important energy source in living organisms and is a component of many carbohydrates. Independent variable: a variable (often denoted by x) whose variation does not depend on that of another. Non-renewable resource (also called a finite resource) is a resource that does not renew itself. Sucrose: a compound (combination of fructose and glucose) which is the chief component of cane or beet sugar. Renewable fermentation: Sugar from plant material is converted into ethanol and carbon dioxide by fermentation. The enzymes found in single-celled fungi (yeast) are the natural catalysts that can make this process happen, unlike ethane, sugar from plant material is a renewable resource. Xylitol: a sweet-tasting crystalline alcohol derived from xylose, present in some plants tissues and used as an artificial sweetener in foods. Yeast: a microscopic fungus consisting of single oval cells that reproduce by budding, and capable of converting sugar into alcohol and carbon dioxide. Baker s yeast (Figure 1), commonly used for baking bread, is the species Saccharomyces cerevisiae. Figure 1: Baker s yeast 3

4 Introduction Fossil fuels, such as oil, natural gas and coal, are a nonrenewable natural resource, meaning that they cannot be replenished. These fossil fuels have started to decline rapidly in our lifetime (Figure 2). We rely on fossil fuels for most of our energy needs such as driving vehicles, powering buildings and day-to-day living. Many of the environmental problems the world faces today including climate change, air pollution, oil spills and acid rain, result from our dependence on fossil fuels. The burning of fossil fuels produces heat-trapping gases that are the main cause of the ongoing rise in global atmospheric temperatures and freakish storm weather patterns. We need to find better ways to power the world without destroying it. Global leaders are searching for clean, renewable options to provide energy and reduce petroleum use. Sun, wind and renewable crops are a valuable resource to address this problem. In particular, sugarcane has emerged as an important alternative resource for meeting those needs. Sugarcane is grown in more than 100 countries and holds the potential to reduce greenhouse gas emissions, expand energy supplies and create jobs. Table 1 shows the leading producers of sugar cane in the world in Sugar (sucrose), through a chemical process of glycolysis (converts glucose to pyruvate) and fermentation (converts sugar to alcohol), produces ethanol. On average, sugarcane produces 7,500 litres of ethanol per hectare. However, it is important to find out which sugars produce the most ethanol to maximise our alternative fuel output. We found out that ethanol burns cleaner than petrol and has a lesser greenhouse impact (Figure 3). Ethanol has a higher-octane rating (i.e. higher compression of the fuel) and can produce more power in the right types of engines (Figure 4). Figure 2: Fossil fuel production 4

5 Table 1: Top 10 sugar producers (2015) Figure 3: Greenhouse emissions 5

6 Figure 4: Power output of Petrol98 vs Ethanol85 Aim The aim is to determine which type of sugar will produce the most ethanol when combined with Instant Dried Yeast. Hypothesis A mixture of sugars will produce the most amount of ethanol compared to single sugars. Variables Independent Variable: Sugar type - 40 g in each bottle (Figure 5) sucrose fructose glucose xylitol coconut sugar Dependent Variable: growth of balloon (CO2 produced) Controlled Variables: 6

7 water (500 ml at 40 C measured with a home thermometer) yeast (Lowan instant dried yeast - 25 g in each bottle) 1L glass bottles (15), coloured balloons, ribbon, ruler The major component of coconut sugar is sucrose (70 79%) followed by glucose and fructose (3 9% each). Figure 5: Sugars and their structures Materials and Methods For weighing the dry ingredients: Propert 5 kg slimline stainless steel digital scales. For liquids: Oxo 11 angled measuring cup (Figure 6). To reduce any repeatable error, we used similar glass bottles, the same funnel, the same scale, balloons from the same packet and one person did each sugar experiment. Figure 6: Materials used in the experiment 7

8 Each type of sugar (120 g Figure 7) was added into a bowl of 1.5 L of warm (40 C) water and then we stirred the mixture until the sugar dissolved (Figure 8). Figure 7: Weighing out the sugar Figure 8: Mixing the sugar and water We then added Instant dried yeast (25 g) to each of the three bottles through a funnel (Figure 9). 8

9 Figure 9: Adding the yeast We poured 500 ml of the warm sugar solution into each bottle. Each bottle was closed and thoroughly shaken until the yeast was dissolved (Figure 10). Figure 10: Shaking the mixture We placed a coloured balloon (a different colour for each type of sugar) on the mouth of the bottle (Figure 11). 9

10 Figure 11: Colour-coding the different sugars After 1 hour sitting at room temperature, we measured the balloon circumference (which filled with CO2 gas) using a ribbon (Figure 12). The ribbon s length was placed on a ruler. To reduce the measuring error, the average of three balloon measurements for each sugar was calculated. Figure 12: Measuring the balloons 10

11 Results The measurements of the circumference of the balloons and observations are shown in Table 2. The average (or mean) is calculated as (C1 + C2 + C3)/3. The standard deviation measures how the values are different from the mean. Microsoft Excel was used to calculate these values. Table 2: Measurements and observations of the balloons. Sugar Brand C1 (cm) C2 (cm) C3 (cm) Mean (Average) Standard Deviation Fermentation observed Gas produced Fructose Lotus Yes A lot Sucrose Merryfield Some Some Glucose Lotus Yes A lot Xylitol Naturally Sweet None None Coconut Power Superfoods The most The most C = Circumference of the balloon. To find out the volume of CO2 produced, we are assuming that the balloons are spheres. We have the values of the circumferences of the balloons and need to use these to find the radius using Equation 1: CC = 2ππππ. Equation 1 Where C = circumference (cm), π = ,r = radius. To find the radius, we rearrange Equation 1: CC/2ππ = rr To calculate the volume, we put the radius into Equation 2: VV = 4 3 ππrr3 Equation 2 Where V = volume (cm 3 ), π = ,r = radius (cm). 11

12 Note that 1 cm 3 = 1 ml and 1000 ml = 1 L. So, we divide the answer by 1000 to get the volume in litres. Type of Sugar Fructose Sucrose Glucose Xylitol Coconut Calculations Radius (cm) = C/2π Volume of CO2 (L) Final values are rounded at the end and given to two decimal places because they are not that accurate. The following graph (done on Microsoft Excel) shows the volume of CO2 produced. Amount of CO 2 Produced Volume (L) Fructose Sucrose Glucose Xylitol Coconut Type of Sugar Figure 13: Graph of amount of CO2 (in litres) produced for each sugar 12

13 Discussion All but the xylitol bottles produced a froth on top of the yeast mixture, with the froth and gas travelling up the bottle. The coconut sugar, which is a combination of sugar types, produced the largest average-sized balloon as predicted in our hypothesis. The standard deviation values for each sugar showed small differences from the average value. A standard deviation close to 0 tells us that the data points are very close to the mean/average (also called the expected value) of the set. This means that the results are very reliable and repeatable. Ethanol fermentation, also called alcoholic fermentation, is a biological process which converts sugars such as fructose, sucrose and glucose into cellular energy, producing ethanol and carbon dioxide as by-products. Alcoholic fermentation is considered an anaerobic process because yeasts perform this conversion in the absence of oxygen (Figure 14). In our experiment, the water bottle was a closed system. Here, the production of CO2 (in the balloon) is directly proportional to the amount of ethanol produced. This means that if ethanol increases, carbon dioxide also increases. Figure 14: Fermentation process In contrast, xylitol caused the balloon to be sucked into the bottle. The reason for this is that xylitol does not ferment. It is already an alcohol and does not release any byproducts, therefore possibly killing the yeast organism. 13

14 Limitations of the experiments Limits of the experiment include the temperature of the water was not kept constant over the time (may need a controlled water bath), we did not measure the room temperature, we would need a laboratory scale and equipment (for more accurate measurements), a balloon exploded (some balloons could be more elastic than others), the balloons were not a perfect sphere and we could be measuring a different circumference. Future work In the future, we should do the exact experiment over three days to see how stable the results are. More statistics may need to be used to see whether the results are meaningful. Although we have received good feedback for the report from many people, an expert s opinion in the bioenergy field would be helpful. We could also measure the CO2 gas using a water-filled measuring cylinder and work out exact amounts of each variables using chemistry. Other variables we could measure include changing the water temperature and ph (i.e. making it more acidic or basic), testing other sugar types and amounts, and using different organisms. We should always wear protective clothing and glasses! Conclusion Many countries have the capability to grow crops, such as coconut palms and sugar cane, which can produce sugar for ethanol production. In this experiment, all the sugars, except for xylitol, produced ethanol which could be measured by the amount of CO2 generated. The coconut sugar produced the most CO2 and therefore ethanol in our experiment. The World Bank s research tells us that coconut trees are better for the environment and produce 50-75% more sugar per acre than sugarcane. Coconuts are an awesome source of power. We hope that this experiment will help people learn more about using alternative and renewable resources so we can stop destroying the planet. Next time you fill up your car with fossil fuels, just think about what you are doing to the Earth. Acknowledgements We would like to thank our teachers and school for supporting the project; our parents for purchasing the products, recording the video, providing feedback and helping with the set out of the report and calculations. 14

15 Log Book The following table shows the order of the events for the project. Date Time Place Activity 02/09/2016 4:00pm Warrawong, NSW Discussed the topic and started planning the project. 09/09/2016 4:00pm Warrawong, NSW Researched the background and methods. 17/09/ :00am Healthy Life, Westfield Figtree Went shopping with dad and bought all the sugars. 17/09/ :15am Woolworths, Westfield Bought the yeast. Figtree 17/09/ :30am The Reject Shop, Westfield Figtree Bought the balloons and glass bottles. 17/09/2016 1:30pm Warrawong, NSW We set up the experiment on the kitchen dining table. 17/09/2016 2:00pm Warrawong, NSW Began experiments and recording. 17/09/2016 5:00pm Warrawong, NSW Finished experiments. 17/09/2016 5:30pm Warrawong, NSW Cleaned up area. 19/09/2016 4:00pm Warrawong, NSW Wrote up the experiments. 23/09/2016 4:00pm Warrawong, NSW Wrote up the results. 30/11/2016 9:30am University of Wollongong, NSW Presented initial project at UOW Science Fair and received feedback. 19/08/ :30pm Warrawong, NSW We worked on the calculations and report. 20/08/ :30pm Warrawong, NSW Worked on report and finished log book. For a recorded presentation of the experiments, please click the link below: Calculations from Excel Fructose Sucrose Glucose Xylitol Coconut St Dev Average Radius Volume Litres

16 Bibliography Acsundergrad: Bing Picture Search: Car advice. Ethanol versus petrol. basics/photos/ Coconut Sugar: Livestrong: Maleszka, R., & Schneider, H. (1982). Fermentation of D-xylose, xylitol, and D- xylulose by yeasts. Canadian Journal of Microbiology, 28(3), Nuclear Power Decline: Pacific Environment: PowerTune Australia: Safe preserving: SugarCane.org: Sustainable Build: What Affects Yeast Growth: cience/assets/aifst/experiments/yeast%20growth.pdf Wikipedia. Baker s yeast. Wikipedia. Standard deviation. 16