Introduction
Biofuel is a fuel that containsenergy from geologicallycarbon fixation. These fuels are produced from living organisms. These fuels are made by a biomass conversion which isconverted to convenient energy containing substances in three different ways: thermal conversion, chemical conversion, and biochemical conversion. This biomass conversionresultsin fuel in solid, liquid, or gas form. This new biomass can be used for biofuels. Biofuels have increased in popularity because of rising oil prices and the need for energy security.
Biodiesel is made from vegetable oils and animal fats. Biodiesel can be used as a fuel for vehicles in its pure form, but it is used as a diesel additive to reduce levels of particulates, carbon monoxide, and hydrocarbons from diesel-powered vehicles. Biodiesel is produced from oils or fats using transesterification.
Production Process
Feedstock Pretreatment
Common feedstock used in biodiesel production includesyellow grease (recycled vegetable oil), "virgin" vegetable oil, and tallow. Recycled oil is processed to remove impurities from cooking, storage, and handling, such as dirt, charred food, and water. Virgin oils are refinedand degumming to remove phospholipids and other plant matter though refinement processes vary.Regardless of the feedstock, water is removed as its presence during base-catalyzed transesterification causes the triglycerides to hydrolyze, giving salts of the fatty acids (soaps) instead of producing biodiesel.
Determination and Treatment of free Fatty Acids
Cleaned feedstock oil is titrated with a standardized base solution in order to determine the concentration of free fatty acids (carboxylic acids) present in the vegetable oil sample. These acidsesterifiedinto biodiesel, esterified into glycerides, or removedthrough neutralization.
Reactions
Base-catalyzed transesterification reacts lipids (fats and oils) with alcohol (methanol or ethanol) to produce biodiesel and an impure coproduct, glycerol. Other methods, such as fixed-bed reactors, supercritical reactors, and ultrasonic reactors, forgo or decrease the use of chemical catalysts.
Product Purification
Products of the reaction include not only biodiesel, but also byproducts, soap, glycerol, excess alcohol, and trace amounts of water. The density of glycerol is greater than that of biodiesel, and this property difference is exploited to separate the bulk of the glycerol coproduct. Residual methanol is typically recovered by distillation and reused. Soaps isremoved or converted into acids. Residual water is also removed from the fuel.
Uses and Application
Cars and Trucks
Several passenger vehicles come with a flex-fuel option that allows them to run on ethanol/gasoline blends from 0 percent to 85 percent ethanol. Even normal gasoline vehicles can operate on a 10 percent ethanol blend. Diesel cars and trucks can run on biodiesel.
Aircraft
Biofuel is used in the aviation industry. Current biofuel production relies heavily on crops that also function as food or livestock feed, emphasis is on developing new sources that don't cause deforestation and compete with food production. A plant called camelina part of the mustard family is in production for making biofuel to be used in aircrafts.
Off-Road Equipment
A large percentage of off-road equipment such as vehicles used in agriculture, mining, forestry, construction, and power and heat productionuse diesel fuel, making this equipment suitable for biodiesel use. Biodiesel has low sulfur contents;off-road biodiesel use can reduce emission levelslowering the consumption of nonrenewable resources.
Small Engines
Small enginesfound in lawn mowers and chainsaws, can use ethanol blends. The barrier to using higher blendshas more to do with manufacturers' warranties than limitations of the technology. Testing indicates that ethanol blends do not harm gasoline engines.
Biofuel in India
Biofuel development in India centers around the cultivation and processing of Jatropha plant seeds which are very rich in oil. Jatropha oil isused in India for several decades as biodiesel for the diesel fuel requirements of remote rural and forest communities; jatropha oil isused directly after extraction (i.e. without refining) in diesel generators and engines. Jatropha has the potential to provide economic benefits at the local level since under suitable management it has the potential to grow in dry marginal non-agricultural lands, thereby allowing villagers and farmers to leverage non-farm land for income generation. Increased Jatropha oil production delivers economic benefits to India on the macroeconomic or national level as it reduces the nation's fossil fuel import bill for diesel production. Since Jatropha oil is carbon-neutral, large-scale production will improve the country's carbon emissions profile. Since no food producing farmland is required for producing this biofuel, it is the most politically and morally acceptable choice among India's current biofuel options.
Technical Survey
High viscosity, low volatility and polyunsaturated character of neat vegetable oils cause chokingand gumming in the stock fuel injector system installed in diesel engines due to deposit formation,carbon buildup and lubricating oil contamination. Several methods are usedforreducing viscosity of vegetable oils such as preheating, blending and transesterification.The transesterification is a chemical reaction widely used in the production of biodiesel. In the transesterification process, a triglyceride reacts with three molecules of alcohols in the presence of a catalyst producing a mixture of fatty acids alkyl esters and glycerol. The monoestersproduced by transesterification of vegetable oils or animal fats are known as biodiesel. Tests were performed on B10 and B20 blends of Hemp and Jatropha biofuels i.e. 10% of biodiesel blended with 90% of pure diesel and 20% of biodiesel blended with 80% of pure diesel. Test engine used in the experiments is a single cylinder four-stroke, naturallyaspirated, constant speed compression ignition engine.The exhaust gas issent to the smoke meter and gas analyzer to measure smokeintensity, CO, CO2, etc.
Market Demand
Demand for renewable fuels is growing.Demand for renewable fuels is spurred by mandated usage levels and new legislation under development in the field worldwide. In addition to mandated usage levels, global economic developments and the growth in the demand for petroleum productsplaysa part in shaping biofuel demand, as mandated usage levels are based on the overall consumption of road traffic fuels in many countries. Demand for renewable fuels has grown steadily in recent years as a result of rising bio-mandated content levels and growing demand for fossil diesel.
Competition is expected to increase, as the marketplace prefers premium-quality biofuels of the type represented by Neste Oil’s NExBTL renewable diesel. High-quality ‘drop-in’ biofuels do not require modifications to existing vehicle engines or existing distribution and logistics systems. Increased competition represents an opportunity for Neste Oil; it will reinforce the benefits offered by premium-quality renewable diesel in the eyes of both customers and legislators.
Impact
· Reduction in import bills due to self sustainability of the country’s energy demands by proper commercialization and implementation of biofuels.
· Generation of income for small holder farmers and generation of employment in rural areas in the ancillary units like cracking, transesterification, transport etc.
· Energy crisis in the rural areas can be met by setting up of decentralized low capacity power stations run on biodiesel.
· Biodiesel can prove to be a boon for the poor farmers by reducing their fuel bills involved in running agro machineries.
· Greening and reclamation of wastelands.
· Tackling the present environmental issues of global warming and rise in sea level by a substantial decrease in emissions of greenhouse gases from biofuels
Indian Biodiesel Initiatives
· •Daimler Chrysler, together with the University of Hohenheim, Germany, and CSIR (Council for Scientific and Industrial Research), India, started a public-private partnership project to test and demonstrate the feasibility of Jatropha biodiesel on internal combustion engines.
· •The UK based company D1 Oils Plc signed an agreement with Mohan Breweries and Distilleries for producing biodiesel from the Jatropha plant. The company has set its targets for planting jatropha on 100,000 hectares of land in India. After maturity, this plantation would yield approximately 250,000 to 300,000 tonnes of crude Jatropha oil per annum.
· •Indian Railways, owned by the Government of India, which consumes about 40 million tonnes of diesel fuel, is planning to cultivate Jatropha along 25,000 km of its railway tracks and other waste lands. It has taken decision to use biodiesel for its diesel locomotives and road vehicles and has entered into a memorandum of understanding with Indian Oil Corporation (IOC) for the supply of biodiesel. IOC buys biodiesel from Gujarat Oleo Chem Limited (GOCL) - the first company to produce biodiesel commercially in India.
· •Dr. M.G.R. Jatropha Biodiesel Project was launched in Chennai an ambitious programme with the objective of promoting waste land regeneration and rural development in Tamil Nadu state under contract farming basis.
Future
The majority of ethanol produced in the country is consumed by the liquor industry and many states in India arenot able to implement the bio-ethanol policy. The non-edible Jatropha oil has the potential to become one of the primarysources of biodiesel, globally.New investments are announced in this field indicatesa rapid development of the biodiesel industry, triggered by higher returns expected from plantations, government encouragement, and the easy availability of waste land in India. Low man power costs and high yield of Jatropha oil, the price of Jatropha biodiesel is expected to be competitive which isa crucial factor deciding the future of the biodiesel industry. The large scale Jatropha plantations promoted by the government are expected to bring down biodiesel prices.The Jatropha biodiesel industry canbecomesuccessfulin India even in the absence of substantial taxexemptions from the government.