Biofuel is a type of fuel that is produced from biomass (that is from plants and animal material). Unlike fossil fuels which take time to form because of the slow geological process, biofuels are readily available and can be produced from other sources apart from plants such as industrial waste with biological origin. Also, biofuel is a cleaner source of energy than fossil fuels and releases fewer pollutants and greenhouse gasses. There are two main categories of biofuel; biodiesel and bio-alcohol. Bio-alcohol is created by the bacterial breakdown of starch in plants while biodiesel is derived from the oil already available in such plants. Below are some of the main crops for biofuel production
Corn is considered as the main source of ethanol-based biofuel. Corn is rich in sugar which is the main source of ethanol. The sugar-rich corn is turned into ethanol through a brewing process which is similar to brewing beer. The kernels are first ground and then mixed with warm water and yeast. Kernels are used because it makes the fermentation process cheaper than when an entire corn plant is used. The yeast causes the mixture to ferment and produce ethanol. The resultant ethanol is then blended with gasoline for use in car engines. Ethanol produced from corn releases less nitrogen oxide, carbon monoxide, and sulfur thus reduces smog in cities.
Rapeseed oil has been used in cooking food and illuminating homes for centuries and is still one of the main sources of biodiesel. The most popular rapeseed oil comes from canola since it contains low erucic acid compared to other rapeseeds. Apart from biofuel, canola is also a source of food for both humans and animals. Although most biodiesels derived from vegetables do not burn well, especially in cold weather because of the highly saturated fats, canola is an exception because it contains low saturated fats which makes it hard for the ice crystals to form. Canola also has higher oil content than other vegetable oils.
Apart from corn, sugarcane is also an important source of ethanol which is considered generally cheaper than gasoline. In recent years, Brazil has made strides in reducing its dependence on fossil fuel and increase the use of biofuel. The government has been encouraging its farmers to plant sugarcane. Ethanol production from sugarcane is almost six times cheaper than producing ethanol from corn. However, despite the use of fewer chemicals in growing the crop, the harvesting of sugarcane which involves burning the field leads to the emission of large amounts of greenhouse gases into the atmosphere.
Palm oil is an energy-efficient biofuel that is extracted from the palm tree. This type of biofuel is environmentally friendly as it releases less carbon dioxide gas into the atmosphere compared to gasoline. Interestingly, cars using diesel engines can run on palm oil without being converted. Palm trees are common along with the coastal areas and are also popular for their fruits. Palm oil has been one of the major contributors to the economies of Indonesia and Malaysia. However, the clearing of tracks of land to plant the crop is considered as an environmental concern.
Jatropha is popularly known as a poisonous weed that grows quickly and requires less water to produce its numerous seeds. However, its seeds are rich in oil content that can be used to supplement crude oil. India is the largest Jatropha producer in the world with its biodiesel industry centered on the crop. Jatropha bush can survive for up to 50 years in a drought-ravaged land. Approximately 0.83-2.2 tons of oil can be extracted from 1 hectare of jatropha.
Soybeans are not only used in the production of shampoos, tacos, and tofu but can also be used in the production of fuel. In the US, most of the biodiesels are produced from soybean oil. Heavy commercial vehicles can efficiently operate on pure soybean biodiesel or a blend of diesel and biodiesel. Soybean biodiesel produces more energy than corn ethanol and is also more environmentally sound. A bushel of soybeans can produce up to 6 liters of biodiesel. However, its oil content is lower than that of sunflower seeds and canola.
Switchgrass has the greatest potential to solve the problem of over-reliance on fossil fuel than any other biofuel crop. Unlike corn or even sugarcane, this wonder plant has a form of cellulose that requires less energy to produce ethanol. The cellulose ethanol in switchgrass also contains more energy than corn ethanol and also emits fewer greenhouse gases. According to researchers, one acre of switchgrass plantation can produce up to 15 tons of biomass or 4,350 liters of ethanol daily. Despite being a potential source of biofuel, there are no great switchgrass farms or plantations.
Sunflower plants are quickly gaining popularity as feedstock crops for biodiesel as they share certain common characteristics with other crops such as canola and soy. The sunflower seeds have a high oil content of up to 40%, making the plant an excellent choice for biofuel crops. The seeds can be processed into biodiesel or the plant waste can be used as biomass to fuel factories and power plants. According to research by the National Sunflower Association, one acre of sunflower can produce up to 600 pounds of oil. However, the quantity of oil extracted from sunflower seeds varies depending on several factors including growing conditions and methods of oil extraction.
Wheat is a source of biofuel used for renewable energy. Traditional biofuels such as ethanol have been derived from several sources including corn and wheat. One of the major benefits of wheat as a source biofuel is that the fuel is derived from wheat pellets which are made from the husk of the crop. Thus, it is possible to produce food and create energy from the same plant. In Europe, 4 million liters of wheat-based ethanol is produced every year. However, the increased use of wheat as a source of energy may divert the grains needed for food.
Although cotton is mainly used as a source of fiber for clothes, cottonseed oil has been used for decades, especially in the US for cooking. Approximately 20% of the cotton plant is oil. It is estimated that an acre of cotton contains more oil than an acre of corn or soy. The main drawback of using cottonseed oil as a car fuel is that it solidifies in cold temperature and would render a vehicle unusable in winter.