However, it would be a waste of good whiskey and the product certainly would not meet the specifications set forth by the American Society for Testing and Materials (ASTM).
Rather, biodiesel production should begin with the guidance of a reputable process-design firm, along with a professional assessment of available production feedstocks—based on price, availability and quality. Of course, the feedstock used for biodiesel production is "fat" derived from vegetable or animal sources. Natural oils and fats are triglycerides—esters of glycerin—and three molecules of fatty acids. From triglycerides, biodiesel is produced in a process called transesterification, during which oil or fat is reacted with an alcohol—usually methanol—in the presence of a base catalyst, such as sodium hydroxide.
Transesterification yields two products: fatty acid methyl ester (FAME), and glycerin.
FAME is biodiesel, and it can be labeled as such, and sold as fuel, if it meets ASTM standards. Note: Crude, de-gummed soybean oil will burn in diesel engines, but such oil is not considered biodiesel, nor would it meet ASTM standards, and it could damage or foul the engine. To become biodiesel, the lipid, or fat, must first be chemically changed into a methyl ester.
Feedstock sources
Although biodiesel can be produced from any triglyceride, the popular fats and oils most commonly used worldwide are:
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The predominant feedstock used in the United States is soybean oil. Other vegetable oils, such as corn, cottonseed, canola (rape seed), flax, sunflower and peanut, also can be used. These seed oils generally are more expensive than soybean oil. However, on several days in October 2003, the cash price of soybean oil did exceed that of corn oil.
Animal-derived products such as tallow, choice white grease (lard), poultry fat and yellow grease are also triglycerides and are used as a biodiesel feedstock. These products, when compared to plant-derived oils, often offer an economical advantage as a feedstock. There is also some indication that these sources, which are high in saturated fats, produce less nitrous oxides compared to plant oils. However, this research is ongoing.
The third main source of triglycerides is recycled oil and grease, usually from restaurants and food processing plants. Although more pre-treatment is required for this feedstock compared to virgin vegetable oils, economically it can be a very attractive feedstock. The use of a recycled product such as used cooking oil is an environmentally friendly process since it solves a waste disposal problem.
On October 30, the U.S. Navy announced a project in which it will produce biodiesel from used cooking oils at Naval Base Ventura County (NBVC) in Port Hueneme, Calif. (see article on page 20). Animal-derived feedstock and recycled cooking oils are readily available from 200-plus renderers in the United States, including such companies as Griffin Industries, Darling, Wintzer, Georgia Protein, National By-Products, Moyer Packing, etc.
Production from soybeans
The main sources of soybean-derived biodiesel feedstocks are:
1. Solvent extraction plants that process 2,000 to 5,000 tons of soybeans per day. These plants are set up to meet both domestic and export markets for protein meal and soybean oil. Most soybean meal for export is shipped from extraction plants with good access to the Port of New Orleans via the Mississippi River and its tributaries. Many large extraction plants also incorporate a refinery operation or have reasonable transportation to a refinery at another site.
2. Mechanical extraction plants set up primarily to produce expeller-type meal, which has bypass protein advantages for ruminating animals. These plants usually are set up to process 24 to 800 tons of soybeans per day. Most small plants do not have in-house refineries. Several new mechanical plants that have been constructed during the past several years do have their own refineries that produce specialty oils. One of the largest mechanical extraction plants in the United States is West Central Cooperative in Ralston, Iowa. In addition to being the largest U.S. producer of bypass protein meal, it is the largest producer of biodiesel in the nation.
The following factors have contributed to the use of soybean oil as the dominant biodiesel feedstock in the United States:
-Soybean oil is readily available in many regions of the country.
-The composition of soybean oil is a relative constant, compared to by-products of food preparation, particularly recycled restaurant grease.
-Historically, soybean oil is less expensive than other vegetable oils.
-There is a high domestic production of soybean oil, compared with other vegetable oils and animal fats. Soybean oil represents almost 60 percent of the total fats and oils produced in the United States.
-Many subsidies and grants in the past have been based on vegetable oils, although most of the new governmental programs are feedstock neutral.
-National soybean associations have done an effective job in promoting the product.
It should be noted that any consideration of biodiesel feedstock supply should include soybean oil, since most of the biodiesel currently produced in the United States uses soybean oil as the feedstock.
A potential biodiesel producer should also be aware of the changes during the past four to five years in the "soybean complex." The soybean complex is the global relationship between the various factors influencing the price of soybeans, soybean meal and soybean oil including supply, transportation, demand, alternate protein and oil sources, animal production and, sometimes, political considerations.
For a better understanding of the dynamics of supply, consumption and prices of whole soybeans and soybean products, the following tables show the changes in the soybean complex domestically and internationally since October 1999. These tables include the latest USDA forecasts for the new marketing year that began October 1, 2003, and ends September 30, 2004.
The influence of China
The most significant influence on the U. S. soybean crushing business since 1995 has been the changes in the import mix of our largest single customer, China. China has changed from being an importer of soybean meal to an importer of whole soybeans. China is now the largest single soybean customer of the United States, with exports expected to reach 7.7 million metric tons in 2002-03.
Brazil is expected to rival the United States’ market position in China with exports of 7.4 million tons during this past year. Chinese import mix, mainly from the "big three" Soybean Producers—United States, Brazil and Argentina—has changed dramatically from 1995-96 through 2002-03.
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