Frequently Asked Questions

What is Biodiesel?

Biodiesel is the name for a variety of ester-based oxygenated fuels made from vegetable oils or animal fats.  The concept of using vegetable oil as a fuel dates back to 1895 when Dr. Rudolf Diesel developed the first diesel engine to run on vegetable oil. Diesel demonstrated his engine at the World Exhibition in Paris in 1900 using peanut oil as fuel.

Properties of Biodiesel

Today’s diesel engines require a clean-burning, stable fuel that performs well under a variety of operating conditions. Biodiesel is the only alternative fuel that can be used directly in any existing, unmodified diesel engine. Because it has similar properties to petroleum diesel fuel, biodiesel can be blended in any ratio with petroleum diesel fuel. Many federal and state fleet vehicles in USA are already using biodiesel blends in their existing diesel engines. The low emissions of biodiesel make it an ideal fuel for use in marine areas, national parks and forests, and heavily polluted cities. Biodiesel has many advantages as a transport fuel. For example, biodiesel can be produced from domestically grown oilseed plants such as canola. Producing biodiesel from domestic crops reduces the USA's dependence on foreign petroleum, increases agricultural revenue, and creates jobs.

Key Advantages of Biodiesel: back to top

  • Biodiesel is the only alternative fuel in the US to complete EPA Tier I Health Effects Testing under section 211(b) of the Clean Air Act, which provide the most thorough inventory of environmental and human health effects attributes that current technology will allow.
  • Biodiesel is the only alternative fuel that runs in any conventional, unmodified diesel engine. It can be stored anywhere that petroleum diesel fuel is stored.
  • Biodiesel can be used alone or mixed in any ratio with petroleum diesel fuel. The most  common blend is a mix of 20% biodiesel with 80% petroleum diesel, or B20.
  • The lifecycle production and use of biodiesel produces approximately 80% less  carbon dioxide emissions, and almost 100% less sulphur dioxide. Combustion of biodiesel alone provides over a 90% reduction in total unburned hydrocarbons, and a 75-90% reduction in aromatic hydrocarbons. Biodiesel further provides significant reductions in particulates and carbon monoxide than petroleum diesel fuel. Biodiesel provides a slight increase or decrease in nitrogen oxides depending on engine family and testing procedures. Based on Ames Mutagenicity tests, biodiesel provides a 90% reduction in cancer risks.
  • Biodiesel is 11% oxygen by weight and contains no sulphur. The use of biodiesel can extend the life of diesel engines because it is more lubricating than petroleum diesel fuel, while fuel consumption, auto ignition, power output, and engine torque are relatively unaffected by biodiesel.
  • Biodiesel is safe to handle and transport because it is as biodegradable as sugar, 10 times less toxic than table salt, and has a high flashpoint of about 125°C compared to petroleum diesel fuel, which has a flash point of 55°C.
  • Biodiesel can be made from domestically produced, renewable oilseed crops such as soybeans, canola, cotton seed and mustard seed.
  • Biodiesel is a proven fuel with over 30 million successful US road miles, and over 20 years of use in Europe.
  • When burned in a diesel engine, biodiesel replaces the exhaust odor of petroleum diesel with the pleasant smell of popcorn or french fries.
  • The Congressional Budget Office, and Department of Defense, US Department of Agriculture, and others have determined that biodiesel is the low cost alternative fuel option for fleets to meet requirements of the Energy Policy Act.


Biodiesel Impact back to top

An important factor that is not usually considered when calculating the costs and benefits of industrial feedstock materials is the macroeconomic effect associated with domestically produced, renewable energy sources. Economic benefits of a biodiesel industry in the US would include value added to the feedstock (oilseeds or animal fats), an increased number of manufacturing jobs, an increased tax base from plant operations and income taxes, investments in plant and equipment, improvement of our trade balance, and reductions in health care costs due to improved air quality and greenhouse gas mitigation.

Biodiesel has positive impacts on the state economy. An Iowa State University study concluded that three economic benefits would accrue to state from biodiesel. First, biodiesel expands demand for soybean oil, causing processors to pay more for soybeans, In addition, soybean farmers near the biodiesel plant would receive slightly higher prices for soybeans; and third, the presence of a facility that creates energy from soybeans would add value to the state's industrial and income base.

Dr. Hayes concluded that, "If the state of Iowa were to mandate the use of a 20 percent biodiesel blend in its state vehicle fleet where feasible, the total additional cost of this policy would range from $400,000 to $500,000. If it could be shown that this policy would result in a new five million gallon biodiesel plant in the state, then the policy would create more new tax revenues than it would cost and would clearly be in the best interest of the state."

Biodiesel has positive implications for production agriculture. A 1996 economic study published by the USDA Office of Energy predicted that a modest, sustained annual market for biodiesel of 100 million gallons in the US would contribute approximately seven cents to the price of each bushel of soybeans produced in the US. Based on last years harvested crop, the increase could have resulted in more than $168 million directly to the use of biodiesel.

Biodiesel has a positive impact on the US balance of trade. A 1998 biodiesel lifecycle study jointly sponsored by the US Department of Energy and the US Department of Agriculture concluded that increased use of biodiesel and biodiesel blended fuels such as B20 would substantially benefit our economy. The report concluded that national spending to import petroleum sends significant amounts of dollars out of our domestic economy every year. Biodiesel offers the potential to shift this spending from foreign imports to domestically produced energy. The report notes: "With its ability to be used directly in existing diesel engines, biodiesel offers the immediate potential to reduce our demand for petroleum in the transportation sector."

Biodiesel contributes jobs to the local economy. Economic work conducted at the University of Missouri estimated the benefits of producing biodiesel in a metropolitan region. This study concluded that 100 million gallons of biodiesel production could generate an estimated $8.34 million increase in personal income and over 6,000 additional temporary or permanent jobs for the metropolitan region.

Biodiesel Usage back to top

Basic Terminology: Biodiesel is the pure, or 100 percent, biodiesel fuel. It is referred to as B100 or "neat" fuel.

A biodiesel blend is pure biodiesel blended with petrodiesel. Biodiesel blends are referred to as Bxx. The xx indicates the amount of biodiesel the blend (i.e., a B20 blend is 20 percent biodiesel and 80 percent petrodiesel).

Ensure the neat biodiesel fuel meets the biodiesel specification for pure biodiesel before blending with petrodiesel. The specification for biodiesel is designed to ensure that consumers will not experience operational problems from the fuel’s use. Make sure that biodiesel meets this specification and that the fuel supplier will warrant this fact. Quality fuel will provide the consumer with improved air quality and enhanced operability. Poor quality fuel will create operability problems and increased maintenance activity. Purchase only qualified fuel from a reputable source. Check fuel filters on the vehicles and in the delivery system frequently upon initial biodiesel use and change them as necessary. Biodiesel and biodiesel blends have excellent solvent properties. In some cases the use of petrodiesel, especially #2 petrodiesel (has not been observed with #1), leaves a deposit in the bottom of fueling lines, tanks, and delivery systems over time. The use of biodiesel can dissolve this sediment and result in the need to change filters more frequently when first using biodiesel until the whole system has been cleaned of the deposits left by the petrodiesel. This same phenomenon has been observed when switching from #2 to #1 petrodiesel.

Be aware of biodiesel's freezing properties and take precautions as with #2 petrodiesel use in cold weather. A 20 percent blend of biodiesel with petrodiesel raises the freezing properties approximately 3° to 5° F (pour point, cloud point, cold filter plugging point). In most cases, this has not been an issue. Twenty percent biodiesel blends have been used in the upper Wisconsin area and in Iowa during -25° F weather with no problems. Solutions to biodiesel winter operability problems are the same solutions used with conventional #2 petrodiesel (use a pour point depressant, blend with #1diesel, use engine block or fuel filter heaters on the engine, store the vehicles near or in a building, etc.). Neat biodiesel will begin to freeze at about 25° F and, if used or stored on site, will need to be kept in an area that will not get below that temperature. Most underground tanks are around 50° F and are not a problem.

Wipe painted surfaces immediately when using biodiesel. As mentioned earlier, biodiesel is a good solvent. Biodiesel can, if left on a painted surface long enough, dissolve certain types of paints. Therefore it is recommended to wipe any biodiesel or biodiesel blend spills from painted surfaces immediately.

Store biodiesel or biodiesel blend soaked rags in a safety can to avoid spontaneous combustion. Biodiesel soaked rags should be stored in a safety can or dried individually to avoid the potential for spontaneous combustion. Biodiesel is made from vegetable oils and animal fats which can oxidize and degrade over time. The oxidizing process can produce heat. In certain environments, for example, a pile of oil soaked rags can become concentrated enough to result in a spontaneous fire. (Note: Paul has a hole in seat of his van to testify to this!!!)

Use the biodiesel within one year. All fuels, including #2 and #1 petrodiesel, have a shelf life. This is also true with biodiesel and biodiesel blends. Industry experts recommend that biodiesel be used within one year to ensure that the quality of the fuel is maintained. Storage time does not impact biodiesel distribution given biodiesel’s production logistics. Biodiesel is generally not stored for long periods of time. Production levels and rates are established to meet demand (similar to "just in time" inventory methods). This is an advantage enjoyed by renewable fuels, like biodiesel, that cannot be shared by its fossil fuel counterparts.

Some if the useful information above comes courtesy of the Biodiesel Association of Australia which has a comprehensive site detailing more useful information about biodiesel. Check them out.

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