Rudolph Diesel Meets the Soybean: "Greasing" the Wheels of

Chemical Education Today

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Rudolph Diesel Meets the Soybean: “Greasing” the Wheels of Chemical Education by Angela G. King and Marcus W. Wright

As a nation, Americans use approximately 26 million barrels of crude oil per day, which amounts to about 3 gallons per day per person (1). The most obvious use of this petroleum is as fuels: for our cars, buses, jets and furnaces. Less obvious to the non-scientist are the industrial feedstock provided through refining crude oil that lead to polymers, pharmaceuticals and other materials that enhance our daily lives. For use as both fuel and industrial starting material, petroleum has a huge impact on American society. However, more than half of the oil consumed in the United States is imported oil. It amounts to $475,000 per minute (or $250 billion per year) spent on foreign oil (1). The political and economic implications of our foreign oil dependence made headlines when Alan Greenspan testified before the Senate Foreign Relations Committee on the world oil market and agricultural sources of alternative fuels on June 7, 2006 (2). Greenspan noted that the balance of supply and demand “has become so precarious that even small acts of sabotage or local insurrection have a significant impact on oil prices.” He also declared that “The energy abundance on which this nation was built is over,” and went on to say that (petroleum) oil need not be the dominant player in our country’s energy future. Even President George Bush, a long time supporter of the oil industry, raised the alarm in his 2006 State of the Union Address when he said “We have a serious problem. America is addicted to oil, which is often imported from unstable parts of the world” (3). Clearly the time is ripe for scientists and educators to help address the problem. We can educate individuals on the science, development, and use of alternative fuels. Biodiesel as an Alternative to Petroleum Biodiesel is an alternative fuel produced by reacting an oil or fat with an alcohol which reduces viscosity. Biodiesel can be used neat or blended with petroleum diesel. The percent biodiesel by volume in a blend is indicated by the percentage following a capital B. For example, using B100 means you put pure biodiesel in your engine while B20 indicates biodiesel is an oxygenate additive to diesel fuel at 20% volume. Blending of biodiesel at even the 2% (B2) level will become significant as the move to the less lubricating ultra low sulfur diesel occurs in 2007. Biodiesel is the only fuel that earns credits for alternative fuel use under the Energy Policy Act of 1992 that does not require the purchase of a new vehicle (4). Biodiesel can be used in a petroleum diesel engine in any car or truck already on the road, with the caution that biodiesel begins to solidify at low temperatures. The U.S. Navy uses B20 in all non-tactical vehicles, and it is in fact the largest user of biodiesel in the world (5). The biodiesel home heating market is also on the rise. 202

Journal of Chemical Education

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The use of vegetable oils for engine fuels may seem insignificant today. But such oils may become in the course of time as important as the petroleum and coal tar products of the present time.

Rudolph Diesel, 1912

While biodiesel may seem like a new idea in response to rising petroleum costs, it is really recycling an old approach. In fact, when diesel engines made their debut in 1900, they ran on pure peanut oil. Rudolph Diesel developed his novel diesel fueled internal combustion engine in response to the noted inefficiency of steam engines. Today it remains to be one of the most fuel efficient engines on the market (6). This efficiency is the same regardless of the fuel used (petroleum or biodiesel); therefore differences in fuel economy are attributed to differences in volumetric energy content (7). Compared to No. 2 diesel, the most widely-used grade of diesel due to its higher energy content and greater lubricity than No. 1 diesel, biodiesel has 8.65% fewer Btu/gal. B20 has only a 1.73% decrease, which is small enough that it would be difficult to detect in day to day use (8). How much biodiesel could be made domestically? Estimates indicate that virgin soy oil could provide 18 billion pounds annually, 55% of the feedstock supply, with animal sources and other virgin plant oils constituting another 36%. While large scale biodiesel production starts with virgin oil, small scale producers often utilize cheap or free used cooking oil, which would also make up 9% of the commercial production feedstock (9). Advantages of Biodiesel Biodiesel advocates identify several benefits to the use of biodiesel. First, it is a domestic product, being prepared either from waste cooking oil or virgin oil pressed from crops, such as canola or soybeans, grown in the United States (10). If only 5% of the imported oil used in the U.S. was replaced with biodiesel it would account for the amount of oil imported from Iraq (11). Clearly exploiting such opportunities will have positive impact on our foreign relations policies. The soybean (Glycine max) is the world’s largest provider of both protein and oil, accounting for 57% of the global oilseed production, and 40% of the world’s soybean crop was grown in the United States. In the U.S., soybeans were

Vol. 84 No. 2 February 2007

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Report photo: Leslie Thomas

Figure 1. Titrating the free fatty acids in waste cooking oil.

photo: Angela King

Figure 2. Layers of biodiesel (top) and glycerin (bottom) quickly separate after reaction. Both products have commercial applications.

planted on 75.2 million acres in 2004, producing a record 3.141 billion bushels of soybeans (12). The bushy, green legume produces 60–80 pods in the fall, each holding three pea-sized beans. A 60-pound bushel of soybeans yields about 48 pounds of protein-rich meal and 11 pounds of oil used in food products and biodiesel production (13). More soybeans are grown in the United States than in any other country in the world, and soybeans and derived products are actually exported around the globe (13). In addition to oil, the beans yield other marketable materials. Lecithin, extracted from soybean oil, is a natural emulsifier and lubricant used in pharmaceuticals and protective coatings. Soybean protein and bran find use in both human food and animal feed products (14). Using oil pressed from domestically grown crops to run our cars would also increase the demand for oil-crops, greatly needed as agricultural commodity prices are at an all-time low. The total crop value in 2004 was more than $17.7 billion but the average price paid to farmers was only $5.65 per bushel (12). Our country clearly has the ability to grow enough soybeans to meet food demands and help address the need for alternative energy sources. Proponents of biodiesel also state that replacing petroleum diesel with biodiesel is good for the environment. According to The National Biodiesel Board, utilizing biodiesel in a regular diesel engine reduces emissions of unburned hydrocarbons, carbon monoxide, particulate matter, and NOx. In fact, biodiesel is the only alternative fuel to have successfully completed the EPA’s Tier I and Tier II health effects testing. Biodiesel production and usage also reduces emissions of carbon dioxide, implicated in global warming, by more than 78% (15). The demand for biodiesel is clearly on the rise. Whether driven by high gas prices, a desire to decrease dependence on foreign oil or concerns for the environment, estimated biodiesel production jumped from 2 million gallons in 2000 204


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to 75 million gallons in 2005, with an increase of 300% in the last year alone (16)! Currently there are more than 60 biodiesel plants under construction to try to meet the ever increasing demand (17). Over half of the plants under construction will use soybean oil as their primary feedstock (17). Biodiesel in the Classroom and Teaching Lab As chemistry instructors, we are faced with the challenges of facilitating students’ mastery of many concepts that appear to the novice as unrelated, nurturing the application of critical thinking and analytical skills data collection and assessment and developing an awareness of the interdisciplinary nature of science. In addition, we are often asked to go the extra mile by helping students recognize the importance of what they are learning, creating excitement, and providing motivation that would otherwise be lacking. Such a task makes finding a golden fleece mere child’s play. Biodiesel presents us with an interdisciplinary topic that matches our standard curriculum in many areas, can introduce societal implications and generate class discussion, and is attractive to students who drive and feel the impact of rising oil prices in their wallet. What young American wouldn’t love to “fill ‘er up” on used oil from the cafeteria? Recognizing the environmental benefits of biodiesel, educators have already successfully introduced it into the laboratory curriculum. This Journal has published an inquiry-based environmental chemistry laboratory where students respond to a mock memo from the National Park Service to develop a synthesis of biodiesel and assess its use at varying temperatures through viscosity measurements (18). Another published experiment for advanced students integrates chemistry by having students synthesize biodiesel, determine their product’s heat of combustion using bomb calorimetry and its cloud point, the temperature at which the fuel begins to solidify, using a UV-vis spectrometer with a temperature controlled


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Figure 3. Example of biodiesel production. A triglyceride from animal or vegetable fat or oil is converted to glycerin and three equivalents of fatty acid methyl ester (FAME) through a base-catalyzed transesterification. The two products can be easily separated.

tives, Content Standard F of the National Science Education Standards, addressing natural resources, environmental quality and science and technology in local, national and global challenges. Biodiesel can easily be made in 2 L soda bottles, and assessment can be as easy as adapting soda can calorimetry for a liquid “fuel” to determine a crude heat of combustion (21). The impact of biodiesel on our classrooms and teaching labs has just as much potential as it does on our country’s energy security. It can help introduce environmental concepts, thermodynamics, titrations, combustion, and chemical reactions. Through considering the production of oil crops, agricultural chemistry and genetic engineering can be discussed with regards to soybean production. Now is the time for scientists and educators alike to work toward the common goal of kicking the petroleum habit. While researchers are exploring new methods and approaches to alternative fuels and renewable energy (22), educators can do their part by ensuring that our education system produces citizens who are aware of the need for alternative energy sources and equipped with a comprehensive understanding of the science behind them. Before Diesel could develop his breakthrough engine at the dawn of the 20th century, someone had to teach him about combustion. Let’s do our part to ensure that at the dawn of the 21st century, Diesel’s counterpart is just as well prepared to start a revolution. Literature Cited

Figure 4. Map showing biodiesel plant sites being expanded or constructed in the U.S., September 2006. Courtesy National Biodiesel Board.

sample cell (19). The reaction between the alcohol and fat or oil that produces biodiesel is a transesterification, a reaction typically covered in undergraduate organic chemistry classes. In this issue of JCE, a two-week organic chemistry experiment is described in which students determine the weight percent of free fatty acids in their starting oil and convert them to methyl esters through

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acid-catalyzed Fischer esterification. They then perform a base-catalyzed transesterification on the triglycerides in their oil and assess the completeness of product synthesis through stoichiometric oxidation of vicinal alcohols by periodic acid (20). But biodiesel is not limited to college science classes. It is a great fit for Science in Personal and Social Perspec-

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1. National Biodiesel Board, Fact Sheet on Biodiesel and Energy Security, available online at http://www.biodiesel.org/ pdf_files/fuelfactsheets/ Energ y_Security.pdf (accessed Oct 2006). 2. Greenspan’s testimony is available in its entirety at http://lugar.senate.gov/energy/ hearings/ (accessed Oct 2006). 3. A transcript of the 2006 State of the Union address is available online at http://www.whitehouse.gov/news/releases/ 2006/01/20060131-10.html (accessed Oct 2006). 4. U.S. Department of Energy Biomass Program, Renewable Diesel Fuel, refer


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7. 8.

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to http://www1.eere.energy.gov/biomass/renewable_diesel.html (accessed Oct 2006). National Biodiesel Board, Backgrounder, available online at h t t p : / / w w w. b i o d i e s e l . o r g / p d f _ f i l e s / f u e l f a c t s h e e t s / backgrounder.PDF (accessed Oct 2006). More information on the development of the diesel engine is available from the University of Houston’s College of Engineering at http://www.uh.edu/engines/epi1435.htm (accessed Oct 2006). “2004 Biodiesel Handling and Use Guidelines”, U.S. Department of Energy, DOE/GO-102004-1999 Revised 2004. “A Comprehensive Analysis of Biodiesel Impacts on Exhaust Emissions”, U.S. Environmental Protection Agency, EPA420P-02-001, October 2002. Ginder, R. Evaluating Biodiesel as a Value-added Opportunity, Agricultural marketing Resource Center, 2004. Available at http://www.biofuels.coop/archive/IA_biodieselopportunity.pdf (accessed Oct 2006). National Biodiesel Board, Benefits of Biodiesel, available online at http://www.biodiesel.org/pdf_files/fuelfactsheets/ Benefits%20of%20Biodiesel.Pdf (accessed Oct 2006). Statistics on U.S. oil imports available from Gibson Consulting, online at http://www.gravmag.com/oil.html#imports or the Energy Information Administration at http://www.eia.doe.gov/ oil_gas/petroleum/info_glance/petroleum.html (both sites accessed Oct 2006). American Soybean Association, Soy Stats 2005, available online at http://www.soystats.com/2005/page_02.htm (accessed Oct 2006). American Soybean Association, Soy Stats 2005, available online at http://www.soystats.com/2005/page_04.htm (accessed Oct 2006).

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14. American Soybean Association, Soy Stats 2005, available online at http://www.soystats.com/2005/page_05.htm (accessed Oct 2006). 15. National Biodiesel Board, Biodiesel Emissions, available online at http://www.biodiesel.org/pdf_files/fuelfactsheets/emissions.PDF (accessed Oct 2006). 16. National Biodiesel Board, Biodiesel Emissions, available online at http://www.biodiesel.org/pdf_files/fuelfactsheets/ Production_Capacity.pdf (accessed Oct 2006). 17. National Biodiesel Board, available online (map and table) at http://www.biodiesel.org/buyingbiodiesel/producers_marketers/ ProducersMap-Construction.pdf (accessed Oct 2006). 18. Clarke, Nathan R.; Casey, John Patrick; Brown, Earlene D.; Oneyma, Ezenwa; Donaghy, Kelley J. Preparation and Viscosity of Biodiesel from new and Used Vegetable Oil. J. Chem. Educ. 2006, 83, 257–259. 19. Akers, Stephen M.; Conkle, Jeremy L.; Thomas, Stephanie N.; Rider, Keith B. Determination of the Heat of Combustion of Biodiesel Using Bomb Calorimetry. J. Chem. Educ. 2006, 83, 260–262. 20. Bucholtz, Ehren C. Biodiesel Synthesis and Evaluation: An Organic Chemistry Experiment. J. Chem. Educ. 2007, 84, 296–298. 21. JCE Editorial Staff Calories-Who’s Counting? J. Chem. Educ. 2004, 81, 1440A. 22. For examples of different approaches to alternative fuels, see J. Chem. Educ. 2004, 81, 1086 and J. Chem. Educ. 2006, 83, 10–14.

Angela G. King and Marcus W. Wright are in the Department of Chemistry, Wake Forest University, Winston-Salem NC 27109-7486; [email protected]


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Rudolph Diesel Meets the Soybean: "Greasing" the Wheels of

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