Biofuels

Biofuels are liquid or gaseous fuels primarily produced from biomass, and can be used to replace or can be used in addition to diesel, petrol or other fossil fuels for transport, stationary, portable and other applications. Crops used to make biofuels are generally either high in sugar (such as sugarcane, sugarbeet, and sweet sorghum), starch (such as maize and tapioca) or oils (such as soybean, rapeseed, coconut, sunflower).

Categories of biofuels

Biofuels are generally classified into three categories. They are

1. First generation biofuels - First-generation biofuels are made from sugar, starch, vegetable oil, or animal fats using conventional technology. Common first-generation biofuels include Bioalcohols, Biodiesel, Vegetable oil, Bioethers, Biogas.
2. Second generation biofuels - These are produced from non-food crops, such as cellulosic biofuels and waste biomass (stalks of wheat and corn, and wood). Examples include advanced biofuels like biohydrogen, biomethanol.
3. Third generation biofuels - These are produced from micro-organisms like algae.

Biodiesel and its benefits

Bio-diesel is an eco-friendly, alternative diesel fuel prepared from domestic renewable resources ie. vegetable oils (edible or non- edible oil) and animal fats. These natural oils and fats are primarily made up of triglycerides. These triglycerides when reacted chemically with lower alcohols in presence of a catalyst result in fatty acid esters. These esters show striking similarity to petroleum derived diesel and are called "Biodiesel". As India is deficient in edible oils, non-edible oil may be material of choice for producing biodiesel. Examples are Jatropha curcas, Pongamia, Karanja, etc.

The benefits of using biodiesel are as follows

• It reduce vehicle emission which makes it eco-friendly.
• It is made from renewable sources and can be prepared locally.
• Increases engine performance because it has higher cetane numbers as compared to petro diesel.
• It has excellent lubricity.
• Increased safety in storage and transport because the fuel is nontoxic and bio degradable (Storage, high flash pt)
• Production of bio diesel in India will reduce dependence on foreign suppliers, thus helpful in price stability.
• Reduction of greenhouse gases at least by 3.3 kg CO₂ equivalent per kg of biodiesel.

Source : Ministry of Petroleum & Natural Gas, Government of India

Biofuels

Jatropha

Jatropha curcas is multi purpose non edible oil yielding perennial shrub. This is a hardy and drought tolerant crop can be raised in marginal lands with lesser input. The crop can be maintained for 30 years economically.

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Sugarbeet

Sugarbeet (Beta vulgaris Var. Saccharifera L.) is a biennial sugar producing tuber crop, grown in temperate countries. Now tropical sugarbeet varieties are gaining momentum in tropical and sub tropical countries, as a promising alternative energy crop for the production of ethanol.

For more information click here(324KB)

Sorghum

Sorghum (S. bicolor) is the most important millet crop occupying largest area among the cereals next to rice. It is mainly grown for its grain and fodder. Alternative uses of sorghum include commercial utilization of grain in food industry and utilization of stalk for the production of value-added products like ethanol, syrup and jaggery and bioenriched bagasse as a fodder and as a base material for cogeneration.

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Pongamia

There is several non edible oil yielding trees that can be grown to produce biofuel. Karanja (Pongamia) is one of the most suitable trees. It is widely grown in various parts of the country.

Salient features of Pongamia

• It is a Nitrogen fixing tree and hence enriches the soil fertility
• It is generally not grazed by animals
• It is tolerant to water logging, saline and alkaline soils,
• It can withstand harsh climates (medium to high rainfall).
• It can be planted on degraded, waste/fallow and cultivable lands
• Pongamiaseeds contain 30-40% oil.
• It helps in controlling soil erosion and binding sand dunes, because of its dense network of lateral roots.
• Its root, bark, leaves, sap, and flower have medicinal properties. Dried leaves are used as an insect repellent in stored grains.

Properties of Pongamia Oil

• Non edible oil is largely extracted from seeds.
• The collected seeds consist of 95% kernel
• The oil content varies between 27 - 40%.
• When mechanical expellers are used for recovery of oil from the kernels, the yield of oil is reported to be about 24 to 26.5%
• The crude oil is yellow orange to brown in color, which deepens on standing. It has a bitter taste, disagreeable odour, and it’s non-edible.
• Apart from use as a biofuel, the oil can be used for lighting lamps, lubricant, water-paint binder, pesticide, and in soap making and tanning industries
• The oil is known to be used for the treatment of rheumatism and human and animal skin diseases.
• The press cake (left over after oil extraction) is rich in Nitrogen and hence can be used for improving soil fertility. The press cake when applied to the soil, also has pesticidal value, particularly against nematodes.

Pongamia seed oil Vs standard petroleum/diesel

• Pongamia seed oil as a bio- fuel has physical properties very similar to conventional diesel.
• It is, however a clean fuel (eco friendly) than conventional diesel

Source : TNAU

Related Resources

1. FAQs on Biodiesel
2. Biomass and Biodiesel for Energy Production from Salt-Affected Lands(870)
3. Production of Bio-diesel from Jatropha(1.4MB)