SCIENCE & TECHNOLOGY
News: IAF’s AN-32 Aircraft formally Certified to Operate on Indigenous Bio-Jet Fuel.
Aviation biofuel is a biofuel used for aircraft. It is considered by some to be the primary means by which the aviation industry can reduce its carbon footprint. After a multi-year technical review from aircraft makers, engine manufacturers and oil companies, biofuels were approved for commercial use in July 2011.
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).
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.
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.
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.
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.
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.
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
Tree Borne Oils (TBOS)
A National Biodiesel Mission was launched by the Planning Commission to cover 2.5 million ha area in the country, to meet 5 % replacement of the diesel requirement of the country. GoI had fixed the target to replace 20 % petrodiesel with biodiesel up to 2011-12 by producing 13.38 million tons of biodiesel annually through plantations of Jatropha alone in 11.19 million ha. The Ministry of Petroleum and Natural Gas has launched biodiesel procurement policy w.e.f. 01.01.2006 @ ` 25 per litre through state owned petroleum companies in 12 states. However, recently for the XIIth Plan, the Department of Agriculture and Co-operation, Ministry of Agriculture, has formulated the Mini Mission III to promote the oil seeds in addition to TBOs for biofuel. The aim of Mini Mission III of National Mission on Oil Seeds and Oil Palm (NMOOP) from the current year is to promote 11 tree borne oilseeds (Simarouba, Neem, Jojoba, Karanja, Mahua, Wild Apricot, Jatropha, Cheura, Kokum, Tung & Olive). The tree borne oilseeds (TBO’s) at present, contribute an insignificant portion of vegetable oil production in the country mainly due to lack of improved varieties, elite planting material and agronomic practices.
Salient features of the National Policy on Bio-fuel
Bio-diesel production will be taken up from non-edible oil seeds in waste/degraded/ marginal lands.
An indicative target of 20 % blending of biofuels, both for biodiesel and bio-ethanol by 2017 has been proposed.
Minimum support price (MSP) for non-edible oil seeds would be announced with periodic revision to provide fair price to the growers.
Minimum Purchase Price (MPP) for purchase of bio-ethanol and bio-diesel would be announced with periodic revision.
Major thrust will be given to research, development and demonstration with focus on plantations, processing and production of biofuels, including second generation biofuels and financial incentives, including subsidies and grants.
If it becomes necessary, a national Bio-fuel Fund could be considered.