Environmental Engineering Reference
In-Depth Information
Kaynar 2006). When compared with the other oil seed crops, soybean acreages are greater in the
United States and this contributes toward the higher availability of soybean oil for biofuel feedstock.
Soybean oil is increasingly used as feedstock for the production of biodiesel.
20.2 BrIeF hIstory oF soyBean ProductIon and oIl ImProvement
Soybeans are native to the Far East and were domesticated and grown as early as 5000 years ago by
farmers in China. They were first brought to North America in 1804, and late in the century U.S. farm-
ers began to grow soybeans as forage for cattle. In 1904, George Washington Carver began studying
the soybean at the Tuskegee Institute and determined that it provided a valuable and versatile source
of protein and oil (www.soystats.com). Because of its unique chemical composition, soybean seed has
become a very valuable and useful agricultural commodity. Among legumes and cereals it has the
highest protein content (40%) and the second-highest oil content (20%). Other valuable components
include vitamins, minerals, and isoflavones that are important to human and animal health (Liu 1999).
As the production of and the potential uses for soybeans increased, the need for greater genetic diver-
sity in them was recognized. In the mid-1920s, William J. “Bill” Morse collected more than 10,000
soybean accessions. Several of these germplasm accessions laid the foundation for the development of
productive varieties and the rapid ascension of the United States and South America as world leaders
in soybean production (www.soystats.com). Now, more than 80% of the world's soybeans are grown by
the United States (33%), Brazil (28%), and Argentina (21%), as shown in Figure 20.1. Soybean demand
around the world continues to increase because of its usefulness as a renewable source for numerous
foodstuffs and industrial products, including bioenergy products from soybean oil (Figure 20.2).
Before World War II, the United States imported 40% of its edible fats and oils. At the advent
of the war, this oil supply was cut and processors turned to soybean oil. Soybean oil now provides
56% of the world vegetable oil production, which far exceeds oil produced from any other crop
(Figure 20.3). Soybean oil has also been shown to be a renewable source of cleaner-burning bio-
diesel when used as a substitute for petroleum-based fuels. Nearly 6 L of biodiesel and approxi-
mately 22 kg of soybean meal can be produced from 27 kg of soybeans. Recently, high fuel costs
prompted the U.S. Congress to create biodiesel tax incentives; biodiesel use has increased from
95 million L in 2004 to 2.6 billion L in 2008 (Figure 20.4).
Although soybeans are used in many products, they are far from perfect. Objectionable char-
acteristics such as a “beany” flavor, indigestible carbohydrates, antinutritional factors, oxidative
Other
4%
Canada
1%
Paraguay
3%
India
4%
China
6%
United States
33%
Argentina
21%
Brazil
28%
FIGure 20.1 (see color insert)
World oil seed production for major oilseed crops.
