In many ways, biodiesel is the perfect fuel for buses and trucks. It produces fewer polluting emissions, supplies of it can be renewed indefinitely, and because feedstock materials can be grown domestically, use of it can help bolster the U.S. economy while lessening this country’s dependence on foreign petroleum products.

Why Biodiesel Is Important

The diesel engines that power most trucks and buses are not only highly efficient power plants; they are also very versatile in the fuels they can use. Rudolf Diesel first conceived of the engine that now bears his name as running on powdered coal. A ruinous engine explosion taught him to value liquid fuels. He subsequently hit on the idea of using vegetable oil. The engine that he demonstrated at the World Exhibition in Paris in 1900 ran on oil extracted from peanuts.

Nearly a century of reliance on dwindling petroleum reserves has taught us the wisdom of looking to Nature’s bounty for our fuels, as Rudolf Diesel once did. Biofuels, such as biodiesel and bioethanol, are good for the environment because they add fewer emissions to the atmosphere than petroleum-based fuels. Biofuels are also made from plant materials, which are available in inexhaustible supply. The energy content of plants comes from the sun through the natural process of photosynthesis. That energy content persists even when plants are processed into other materials.

Biodiesel Provides a High Energy Return and Displaces Imported Petroleum

Life-cycle analyses show that biodiesel contains 2.5 to 3.5 units of energy for every unit of fossil energy input in its production, and because very little petroleum is used in its production, its use displaces petroleum at nearly a 1-to-1 ratio on a life-cycle basis. This value includes energy used in diesel farm equipment and transportation equipment (trucks, locomotives); fossil fuels used to produce fertilizers, pesticides, steam, and electricity; and methanol used in the manufacturing process. Because biodiesel is an energy-efficient fuel, it can extend petroleum supplies.

Biodiesel Reduces Life-Cycle Greenhouse Gas Emissions

When biodiesel displaces petroleum, it significantly reduces greenhouse gas (GHG) emissions. By one estimate, GHG emissions (including carbon dioxide [CO2], methane, and nitrogen oxide [NOx]) are reduced by 41%, if biodiesel is produced from crops harvested from fields that were already in production. When plants such as soybeans grow, they take CO2 from the air to make the stems, roots, leaves, and seeds (soybeans). After the oil is extracted from the soybeans, it is converted into biodiesel. When the biodiesel is burned, CO2 and other emissions are released and return to the atmosphere. This cycle does not add to the net CO2 concentration in the air because the next soybean crop will reuse the CO2 as it grows. When fossil fuels such as coal or diesel fuel are burned, however, 100% of the CO2 released adds to the CO2 concentration levels in the air.