Published on October 16th, 2007 | by Stephanie Evans0
Fueling a Biodiesel Nation
The year was 1996, and I was a college student on a semester abroad in Europe studying agriculture and energy—the two cornerstones of American society. While working on a small organic farm in former East Germany, I saw something that changed my life. We were harvesting fields of yellow flowering plants and crushing their seeds to extract vegetable oil, which was taken to a large stainless steel machine owned cooperatively by local farmers.
Inside of that machine, something incredible happened: the vegetable oil that we had pressed from the yellow rapeseed was transformed into a fuel that could run in any diesel engine. The farmers called this fuel biodiesel. To the farmers, the process was simply a routine operation, but to me it represented a complete revolution in thinking. If we could simply "grow" our own fuel, then why was America so fixated on petroleum?
Benefits of Biodiesel
Biodiesel has five qualities that make it an ideal fuel for the American transportation industry right now.
- Biodiesel is made from any type of vegetable oil, so its source crop can be grown in any region of the United States.
- Biodiesel is renewable: it can be grown year after year, regardless of fossil oil supplies.
- Biodiesel is compatible with any diesel engine. No or little modification is needed to use biodiesel in a diesel engine. The implications of this compatibility are huge—one of every three gallons of fuel consumed in the United States is diesel fuel, since diesel engines are the backbone of the American transportation and agricultural industries.
- Biodiesel reduces a host of emissions, including a near total reduction of carbon dioxide and sulfur dioxide, as well as substantial reductions in carcinogenic aromatics and ozone-forming particle emissions.
- Biodiesel’s energy balance ratio is approximately 1:3, or 300%, meaning that for every one unit of energy that goes into making the fuel, three units of energy are present in the final fuel. This ratio exists because, with biodiesel, crops create the energetic hydrocarbon chains that are the basis for the fuel. These crops are fueled primarily by solar energy, and thus biodiesel is a "liquid solar fuel."
Biodiesel is not perfect, though. It does not perform as well as diesel in cold weather and can "gel." Care must be taken in transporting and storing biodiesel because it is a cleansing agent and tends to dislodge dirt and sludge. The use of biodiesel can also lead to an increase in emissions of nitrogen oxides (NOx), emissions that were, until recently, thought to be a primary contributor to smog-forming ozone. In the energy market, though, these challenges are overshadowed by biodiesel’s high utility. Due to the ease of integration into existing infrastructures, the simplicity of manufacturing the fuel, and its favorable energy balance ratio, biodiesel is poised to become a major force in the American energy market.
Growing Biodiesel Feedstocks
Biodiesel can be made from a number of common crops like soybeans, many of which are already grown in America. Processing biodiesel into fuel employs people both on the farm, and in the localized crushing, processing, and transport industries. From the moment that a seed is planted until the time that the vegetable-oil-derived fuel reaches vehicle fuel tanks, dollars that would normally be sent overseas to procure oil are cycled through the U.S. economy, keeping domestic business and industries healthy and strong. On the consumption end, biodiesel has the potential to offer Americans a real choice at the gas pump: fuel from the Mid East or fuel from the Midwest.
The process of making biodiesel has evolved into an exacting science. Today biodiesel is made in at least 35 processing plants across the country. Because the chemical reaction for biodiesel production is similar to that used for soap making, biodiesel can also be made on a small scale, which makes biodiesel an ideal fuel for use in developing nations.
While there are a few types of chemical reactions used to make biodiesel, the most common reaction utilizes three basic ingredients: vegetable oil or animal fats, an alcohol, and a catalyst. The alcohol used in the biodiesel reaction is typically methanol (also known as "wood alcohol") but ethanol (also known as "grain alcohol") can also be used. The catalyst is often sodium hydroxide (NaOH), commonly known as lye or "caustic soda." To make biodiesel:
- The large vegetable oil molecules (which have three fatty acids connected to a glycerin molecule) must be "broken down."
- The molecules are then combined with methanol to form three new smaller chains called methyl esters. Since this method of making biodiesel involves transforming one type of ester into another, the process is called transesterification.
Glycerin, a sugar, is the syrupy by-product of the transesterification reaction that occus in the process of making biodiesel. Glycerin is used in a vast number of household products including soaps, artificial sweeteners, solvents, cosmetics, inks, plastics, lubricants, and antifreeze.
Biodiesel can be blended in any ratio with petroleum diesel. The letter "B" followed by a percentage designates the amount of biodiesel in the blend. For example, a blend of 5% biodiesel and 95% diesel is called B5, a blend of 20% biodiesel with 80% diesel is called B20, and so on. B20 qualifies as a compliance option under the Energy Policy Act of 1992, the Department of Energy’s alternative fuels act, and under Executive Order 13149. B20 is now widely used to power U.S. vehicle fleets including those operated by the military, National Parks Service, Postal Service, NASA, and more than 130 schools districts and universities. B20 is also appealing for fleet use because it considerably reduces emissions, is reasonably priced, and requires few, if any, engine modifications.
Biodegradability and Toxicity
Biodiesel fuel is biodegradable and nontoxic. In fact, B100 is as biodegradable as dextrose (sugar) and less toxic than table salt. Several studies have shown biodiesel to biodegrade up to four times faster in water than petroleum diesel fuel, with up to 98% biodegrading in three weeks. The reduced emissions, pleasant odor (biodiesel exhaust smells faintly like French fries or donuts), biodegradability, and safety of biodiesel make it well suited for use in marine environments and sensitive ecosystems, such as our national parks and forests.
Biodiesel fuel is biodegradable and nontoxic. In fact, B100 is as biodegradable as dextrose (sugar) and less toxic than table salt. Several studies have shown biodiesel to biodegrade up to four times faster in water than petroleum diesel fuel, with up to 98% biodegrading in three weeks.
By contrast, petroleum oil—a known toxic contaminant—poses a serious threat to fresh water and marine environments. An average of 600,000 barrels of petroleum oil a year is accidentally spilled from tankers transporting the fuel, according to the Alaska Oceans Program. Death and disease caused by polluted coastal waters costs our global economy $12.8 billion a year.
Biodiesel has a bright future as an alternative fuel, both as a fuel blend (B20) and on its own (B100). As biodiesel manufacturing and diesel engine technology improve, we’re likely to see biodiesel become more resistant to cold weather and generate even fewer emissions. New government requirements mandating the use of low sulfur diesel fuels stand to further increase demand for biodiesel as a fuel component, blend, or fuel alternative. While biodiesel does have drawbacks, its similarities to conventional diesel in terms of performance, low cost, and compatibility with our existing fuel infrastructure make it an ideal solution for meeting emerging federal emissions requirements and improving air quality now.
Article Contributors: Josh Tickell