Grow Your Own Fuel

Vegetable oils contain energy which came directly from the sun. Vegetable oil crops such as peanuts, sunflowers, and soybeans concentrate solar energy in their oils. Whereas fossil oil was made over a period of hundreds of millions of years, it takes as little as a few months to grow vegetable oil from seeds. Vegetable oil is a practical Diesel engine fuel in many locations. For example, numerous islands produce electricity with Diesel generators. These islands import diesel fuel which costs several dollars a gallon while they export coconut and palm oils for a few cents a gallon. By using locally grown vegetable oil for fuel, islands and countless other communities around the world can benefit from reduced fuel costs as well as lower localized emissions.

TEN COMMON OIL PRODUCING CROPS

There are over 350 species of oleaginous, or oil-producing plants and thousands of sub-species. This chapter concentrates on ten plants which are commonly found in different regions of the world. The following table gives average annual oil yield in pounds of vegetable oil per acre and kilograms of vegetable oil per hectare for ten common oilseed crops. Many plant species produce more oil in tropical climates and conditions. Some species can be harvested more than once a year. For a more extensive chart of oil-producing crops, see Appendix .

Oil Palm
The African palm. or oil palm, is the highest oil-producing tree on earth. One hectare of oil palm can yield up to 5 metric tons of oil per year. The African palm produces two types of oil, palm oil and palm kernel oil. Palm oil is extracted from the fleshy outside, or mesocarp, of the fruit. This oil is used to make soaps, candles, margarine, and cooking oils. Palm kernel oil is extracted from the inner kernel of the fruit. Palm kernel oil is similar to coconut oil and is solid at room temperature. It is used to make mayonnaise, cooking oil, ice cream, and baked goods. The pressed cake is used as an animal feed. The African palm grows to a height of 24-60 feet (8-20 meters). The tree is found along the African coast from Libya to Angola and has spread to regions of the Indian Ocean, including Zanzibar and Malagasy. The African oil palm is slightly hardier than the coconut and is often grown in subtropical regions as an ornamental tree.'

Coconut
The coconut tree is one of the ten most useful trees in the world. The coconut tree grows to a height of 10-90 feet (3-30 meters). The coconut may have originated in South America but it can now be found in all tropical regions of the world. Among the hundreds of items made from different parts of the coconut tree are margarine, lamp oil, hydraulic oil. ice cream, alcohol, vinegar, lubricant, filters, plastics, bowls. clothing, rope, boat rigging, animal feed, and rubber. Different species of the coconut tree will live in high pH soils, low pH soils, sand, latrine runoff, on inclines, and in other adverse conditions. The coconut tree begins to produce fruit in 5-9 years and is in full production by 13 years, soil conditions permitting. Coconut trees live for between 30-90 years depending on the variety and local conditions. Coconut trees provide food for millions of people around the world. Extraction of coconut oil is one of the oldest seed-crushing industries. Coconut oil is the third most produced oil in the world, after peanuts and soybeans. To make coconut oil, the meat, or copra, of the coconut is peeled from the husk, dried in the sun or in dryers, and pressed. The white copra contains between 60-75% oil.2

Jatropha
Jatropha is a versatile crop which is native to the Americas. The Portuguese used jatropha oil for lantern fuel and spread jatropha seed around the world. Today, jatropha is common in Brazil, Fiji, Honduras, India, Jamaica, Panama, Puerto

Rico, El Salvador, Mexico, and in much of Africa. Jatropha is used to make soap, food, medicine, and poison. Unlike the other oil-producing crops we discuss. the jatropha plant is a bush which lives for up to 4( years. It is grown in many places as a hedge tc divide properties, fence animals, and reverse soi erosion. Jatropha produces seed year-round it irrigated. It is especially resistant to drought anc can be planted in desert climates. Jatropha grow, from a seed or cutting and quickly establishes itself. In addition to its other positive characteristics, an acre (2.47 hectares) of irrigated jatropha can produce over 500 gallons (1,900 litres) of oil per year. Jatropha ha~ numerous medicinal characteristics and i, rumored by the Jamaicans and other traditiona peoples to contain a cure for cancer.

Rapeseed/Canola
The yellow flowering oil crop called canola in the United States is known as rapeseed in Europe. Rapeseed is grown in colder regions such as Germany, Canada, and Russia. Although inedible to humans, the meal from the rape plant is a good animal feed. Most of the biodiesel in Europe is made from rapeseed oil. Yields of oil of rapeseed range from 100-200 gallons (380-760 litres) per acre and are among the highest of any conventional oil crop.' The majority of the biodiesel research to date has been done on Rapeseed Methyl Ester (RME) and Rapeseed Ethyl Ester (REE).

Peanut
Peanuts are native to South America and grow well in warm climates and sandy soil. The peanut plant has a slightly lower oil yield per acre than rape/canola and a slightly higher average yield than soybeans.' The Diesel engine was shown being powered by peanut oil at the 1900 World Exhibition in Paris. One University of Georgia tractor runs on 100% peanut oil, while two University of Georgia buses operate 8 hours a day on a 30% mixture of peanut oil and diesel fuel.' Peanut oil can he made on a faun usinoo a Sheller and a press.

Sunflower
Sunflowers are an aesthetically pleasing oil crop. They grow between 15 inches and 8 feet (0.7-3.5 meters) tall and prefer warm temperatures and rich soil. Sunflower crops yield slightly less oil per acre than do rapeseed/ canola crops. Sunflower oil is the second most important edible oil in the world and is used for cooking, margarine, salad dressings, lubrication, soaps, and lighting. Sunflower is the only major oil crop native to western North America.'

Safflower
The safflower is a thistle-like plant which grows to a height of approximately 4 feet (1.3 meters). Safflower grows well in the same regions as cotton and barley and usually hears a yellow or orange flower. The safflower plant was grown prehistorically in India, Egypt, and Persia. Today, India is the largest grower of safflower. Safflower is grown exclusively for its oil which is high in essential unsaturated fatty acids. The oil is light in colour and is used in salad and cooking oils, margarine, liqueurs, candles, paints, linoleum, and varnishes. The flowers can be used to make yellow and red dyes. The safflower crop is grown and processed using the same machinery that is used for small grains. It has a growing season of 150-200 days."

Soybean
The soybean, or soya, plant has been cultivated in East Asia for the past 5,000 years. There are more than 2,500 known species of soybean cultivated in the world. The soybean is the most commonly grown crop in the United States. The soybean is a high protein bean of approximately 20% oil and 80% meal by weight.' Most of the biodiesel made in the United States is made from either virgin soybean oil or used cooking soybean oil. Soybeans are not the best suited crop for oil production. Nevertheless, the soybean is a well-researched. hardy species that yields a protein suitable for both human and animal consumption.

Hemp
The hemp plant grows to 15 feet (5 meters) in height and bears a hard, nutty seed. For 5,000 years, hemp has been grown and processed in Russia. China, and other parts of Asia where it has been used as a source of fiber and food. Some countries are experimenting with growing hemp for paper and textile fiber. The seed of the hemp plant contains approximately 30% oil. While the hemp seed contains a higher percentage of oil than the soybean, the average annual per acre yield of hemp oil is lower than that of soybean oil. Due to the many varieties of hemp, annual per acre oil yields vary.

Corn
Also known as maize, corn is a native grain crop of the Americas. Corn has been cultivated for more than 5.000 years from sea level to over 9,000 feet (3,000 meters), and from Chile to southern parts of Canada. Corn grows to 6-9 feet (2-3 meters) in height. Corn is used for 75% of the world's starch and is the third most important grain in the world after wheat and rice. This hardy crop is resistant to depredation by birds and produces the largest amount of grain per hour of labour. Since only 7-8%h of the grain is oil, corn oil is a bonus byproduct. Processed corn oil is used extensively in the United States as a fast food frying oil." Among its many uses, corn starch is used to make ethanol, a renewable alcohol fuel. A corn crop can produce both ethanol and vegetable oil fuels.

SMALL AND LARGE SCALE OIL PRESSES

There are two types of oil presses which are useful for both small and large scale vegetable oil processing. The most common type of oil press is the screw press. This press uses a large diameter screw inside a metal housing. The oil seed is fed into the top of the press and falls into the churning screw. As the seed is churned into a mash by the turning threads of the screw, the oil is squeezed from the meal, or cake. The protein cake from the oilseed oozes from the side of the press and the vegetate oil dribbles from the bottom of the press.

Screw presses are available in sizes ranging from table-topmodels to industrial models which can produce 2,000 pounds (4,400 kilograms) of oil per day. Screw presses are available in electrical powered and Diesel powered models. Screw presses tend to be slow and they sometimes produce oil with bits of meal still in it. A ram press is a more efficient oil press design. This press uses a hydraulic piston inside of a cylinder to crush the oilseed.'' Ram presses can be powered by hand, by an electric motor, or by a Diesel engine.

Oil Settling
After a vegetable oil is pressed, it is often left to settle for a few days in a horizontal settling tank. The vegetable gums and pieces of meal cake will settle to the bottom of the tank. If the vegetable oil is to be used as a fuel, it should be pumped through a series of filters. First, it should be passed through a 150 micron mesh screen, then through a 70 micron mesh screen, then through a 25 micron filter, and then through a 10-15 micron fuel filter.

Diesel Powered Presses
Most of the mid to large sized oil presses can be powered with Diesel engines. When used in conjunction with a Diesel engine which has been modified to burn straight vegetable oil, these presses can produce their own fuel. In addition to producing their own fuel, Diesel powered presses can provide fuel for entire communities or villages. Diesel powered generators, mills, and pumps can run on the vegetable oil produced from a local resource such as jatropha oil. The combination of a Diesel powered press and a Diesel generator can offer many people who live in rural or isolated areas an inexpensive, sustainable system of generating electricity.

HOW MUCH CAN WE GROW?

One of the most commonly asked and controversial questions about biodiesel and vegetable oil is how much can we grow?

U.S. Potential
The United States is the largest single consumer of fossil fuels in the world. Each year, the U.S. consumes 125 billion gallons (475 billion litres) of gasoline and 60 billion gallons (228 billion litres) of diesel fuel."

The United States generates over 3 billion gallons (11.3 billion litres) of used frying oil annually. This equates to 5% of U.S. diesel fuel use. Using this fryer oil as a fuel stock offers a way to 'jump-start' the biodiesel industry.

Each year approximately 60 million acres (24 million hectares) of U.S. cropland are left fallow. By growing rapeseed, which produces 100 gallons of oil per acre, the U.S. could feasiblely grow 6 billion gallons (23 billion litres) of vegetable oil on fallow cropland. This equates to approximately 10% of U.S. annual diesel fuel usage.

By using used cooking oil and fallow cropland, the U.S. could boost biodiesel to 15% of its annual diesel fuel usage without displacing any current food production. Europeans have been using high efficiency farming techniques to double the vegetable oil production from an acre of land. Some European rapeseed yields are up to 5,0(X) pounds of seed per acre. compared to only 2.000 pounds per acre in the United States." Such high efficiency farming could double the potential fuel grown on fallow cropland in the United States. According to researchers at the University of Idaho, as much as 24% of U.S. diesel fuel could be produced from high production rapeseed grown on fallow croplands." This figure is encouraging, but the quantity of vegetable oil that the United States could grow from rapeseed is dwarfed by the potential quantity of fuel that could come from oil-producing algae.

FUEL FROM ALGAE

Algae are the most efficient biological producer of oil on the planet. Algae may soon be one of Earth's most important renewable fuel crops. According to research funded by the DOE, algae could produce more than enough oil to fulfill U.S. diesel fuel needs.

Scientists at the National Renewable Energy Laboratory (NREL) have cultivated and cataloged 300 strains of algae which eat carbon dioxide and produce oil. In a $25 million program funded by the DOE called the Aquatic Species Program: Biodiesel from Algae. NREL researchers established a number of algae testing ponds including a pond facility in the desert near Roswell. New Mexico.

The quantity of oil that can be produced by algae is astonishing. At the Roswell site, diatom algae productivity reached 50 grams of algae per square meter per day. Each pond was 1,000 square meters in size. There was a possible daily yield of 50.000 grams of algae from each pond. 50.0(10 grams is equivalent to 50 kilograms or 110 pounds. Diatom algae are approximately 50% oil by weight. This is a possible yield of 25 kilograms of oil per day per 1,000 square meters. Per year, this equates to 9,125 kilograms or 20.075 pounds of oil per pond. Rounding up for convenience, we will assume that oil weighs 10 pounds per gallon (1.2 kilograms per litre). That means that in one pond in one year, 2,007 gallons (7,600 litres) of algal oil could be produced. Comparatively, only 50 gallons (190 litres) of oil can be produced with high-yield canola plants in 1,000 square meters of space. Even at 10% efficient oil extraction. one pond of algae would yield 200 gallons (760 litres) of algal oil per year, an increase in production over canola by a factor of 4.

The NREL researchers concluded that on 490,000 acres (200,000 hectares) of land in the U.S., I quadrillion BTUs, or I quad, of algal oil could be produced. One quadrillion BTUs (1.000.000,000,000.000) is approximately equal to ten billion gallons (10,000,000,000) or 3.8 billion litres of oil. According to the researchers, "algal biodiesel could easily supply several `quads' of fuel."" This fuel could be grown on less than I million acres (400,000 hectares), or 1/60th of the currently fallow cropland in the United States. The NREL researchers estimate that once an economy of scale production is reached with algae, algal biodiesel could be produced for approximately $1.65 per gallon.="

The paste is then spun in a large three-phase centrifuge to extract more moisture. The last step of the process is to use a solvent which is used in soybean oil extraction to extract the oil from the protein and carbohydrate parts of the algae. Themochemical liquification is another method of algal oil extraction. This process converts algae into oil by using high heat and pressue. Algal oil extraction methods have achieved oil yields of 30-40%."

The Future of Algal Oil

Due to the simplcity of algae cultivation and processing, algal oil-based biodiesel will soon become reality. In the words of the scientists who wrote the closing report for the DOE on their research with algae, "...this report, should not be seen as an ending, but as a beginning. When the time is right, we fully expect to see renewed interest in algae as a source of fuels and other chemicalS." The time for interest and research into algal fuel is now.

How Algae Grow

Algae could supply the fuel needs of our planet with little land and water because algae reproduce more rapidly than any other form of plant life. Algae reproduce by cellular division. They divide and divide and divide until they fill whatever space they are in or exhaust their nutrients.

Algae grow with little more than sunlight and water. Algae will grow faster if levels of carbon dioxide and nutrients are increased in algae ponds. According to NREL, algae consume more carbon dioxide than other plants. To keep the algae in their experimentation ponds alive, NREL researchers bubbled bottled carbon dioxide into the algae ponds. Algae ponds could use carbon dioxide emissions from power plants as a source of nutrients.

Conditions for Algae Production

The strains of diatom algae that NREL scientists experimented with grew in saline water in very hot, dry climates. The southwestern United States has many locations suitable for algae production. Earthrise Farms and Amway are the two largest producers of nutritional spirulina algae in the continental United States. Their pond farms are located in the southern California desert where daytime temperatures reach 120° F (50° C).

Since oil-producing algae can grow in saline water, there is no competition for water between algae agriculture and food agriculture. In addition, the areas targeted for the highest production per acre of algae are desert climates which are largely unused and unsuitable for traditional food crop cultivation. Algae can also be grown in wastewater treatment facilities.

Algae cultivation is not limited to hot, dry climates and algae can also grow in fresh water. Algae are capable of growing in and adapting to numerous climates and growing environments. There are algae cultivation ponds across the United States in such places as Pennsylvania, Tennessee, Florida, and Oregon.

Processing Algae into Fuel
Several processes for algal oil extraction have been developed. The simplest process, called physical extraction, uses a filter or a chemical to separate the algae from the water in which they grow. The filter or chemical forces the algae to clump together, resulting in algae paste.