Turn Plants into Biofuel with the Power of Enzymes *
Are biofuels the wave of the future? People often talk about these plant-derived fuels as a way to someday cut down on our dependency on non-renewable carbon-based fuels, like gasoline. Ethanol (a type of alcohol) is a common biofuel used today. In the United States, ethanol is a common biofuel additive to normal gasoline. In fact, some states mandate that when you fill up your gas tank, 10 percent of the total fuel volume be made of ethanol. Brazil, the world's largest user of ethanol-based fuel, has been using ethanol biofuel to power cars since 1975.
Figure 1. The fuel options at this Chevron gas station in California include E85, a gasoline containing 15 percent ethanol by volume. (photo courtesy of Propel Inc., 2011)
There are different types of ethanol-based biofuels, but one that's of growing interest for economic and environmental reasons is cellulosic ethanol. Cellulosic ethanol is made by converting the cellulose found in plant cell walls into ethanol, through a series of chemical reactions, as shown in Figure 2, below. Other types of ethanol use the edible parts of plants that are high in sugar, like corn and sugar cane, but there have been concerns that this is lowering the supply of some foods worldwide. However, cellulosic ethanol has the advantage of being made from the non-edible parts of plants, including corn stalks, citrus peels, and grasses. These are plant parts that are often just thrown away as waste.
Figure 2. Cellulosic ethanol is produced by collecting cellulose from plants (A), isolating the cellulose from the other plant materials (B), using enzymes to break down the cellulose into glucose (C), and then turning that glucose into ethanol through fermentation (D). (Photo courtesy of Bio-Rad Laboratories, Inc.)
One of the challenges has been getting the chemical reactions necessary for cellulosic ethanol production reactions to occur in an efficient manner. This has led scientists to research various enzymes that can help speed up the reactions. One of the enzymes they've discovered is cellulobiase. Cellulobiase (an enzyme in the cellulase family) is used in one of the chemical reaction steps to help convert the cellulose into glucose. The glucose (a type of sugar) can then be fermented to create ethanol. But how does cellulobiase work? How much more efficient is the reaction when the enzyme is added? What conditions are best to maximize the cellulobiase efficiency? Using the Carolina EcoKits®: Ethanol Biofuel kit as a starting place, you can investigate these questions yourself. You can even take the project a step further and look for other naturally occurring enzymes, like others in the cellulose family, and compare their impact on the reaction. Or continue the process and use microbial fermentation to create your own ethanol biofuel. Who knows, you might discover something important to help fuel up today's cars!
Cite This PageGeneral citation information is provided here. Be sure to check the formatting, including capitalization, for the method you are using and update your citation, as needed.
Last edit date: 2018-10-17
Ask an ExpertThe Ask an Expert Forum is intended to be a place where students can go to find answers to science questions that they have been unable to find using other resources. If you have specific questions about your science fair project or science fair, our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.
Ask an Expert
If you like this project, you might enjoy exploring these related careers:
Biofuel or Biodiesel Technology & Product Development ManagerSoybeans, corn, grass, algae, vegetable oil: What do these things have in common? The answer is that they can be used to create biofuels, which are derived from plants or plant material. These sources are called biomass. The procedure for converting plants or vegetable oil into a biofuel is a chemical reaction that has many steps. The biofuel or biodiesel technology and product development manager is a professional who develops ways to convert the raw material into fuel and improve the types, growth, and yields of biomass sources. This green job has the potential to greatly influence how we meet our future energy needs. Read more
Chemical EngineerChemical engineers solve the problems that affect our everyday lives by applying the principles of chemistry. If you enjoy working in a chemistry laboratory and are interested in developing useful products for people, then a career as a chemical engineer might be in your future. Read more
BiochemistGrowing, aging, digesting—all of these are examples of chemical processes performed by living organisms. Biochemists study how these types of chemical actions happen in cells and tissues, and monitor what effects new substances, like food additives and medicines, have on living organisms. Read more
News Feed on This Topic
Looking for more science fun?
Try one of our science activities for quick, anytime science explorations. The perfect thing to liven up a rainy day, school vacation, or moment of boredom.Find an Activity