Coal, crude oil, etc. are fossil fuels and their combustion releases large quantity of Greenhouse gases into the atmosphere. The impact of burning these is already evident with rising concerns in the environment. Fossil fuels can deplete atmospheric Ozone, which protects the Earth from harmful solar radiations. Replacement of fossil fuels with green fuels is a very practical way to tackle the increasing human impact on the natural environment.
It is produced by the transesterification of fats or oil and its composition is quite similar to that of fossil or mineral diesel. Fatty Acid Methyl Ester (FAME) is the chief chemical component of biodiesel. 100% biodiesel releases lowest emission of all green fuels apart from Hydrogen and Liquefied Petroleum Gas (LPG), which are not as readily available as biodiesel is. It can be used in conjugation of regular diesel to fuel motors developed post 1994.
Biodiesel has flashpoint of 148°C, is less toxic than table salt and biodegradable as sugar. Biodiesel is a good solvent and effectively cleans the combustion chamber by dissolving residual deposits of mineral diesel. This may lead to more frequent replacement of engine filters but maintains the efficiency of the motor. Moreover, being an oxygenated fuel, biodiesel contains relatively less carbon and more oxygen as well as hydrogen content.
Bio-fuel gasoline is produced from glucose with the help of Genetically Modified Escherichia Coli bacteria was developed by researchers in 2013. Scientists believed that they can further modify the genes of bacteria and produce gasoline from animal manure or even straw.
Methane released by the anaerobic digestion of organic matter by anaerobes is called Biogas. It can be produced from biodegradable waste or could be extracted by feeding energy crops into anaerobic digesters. The solid by-product of the process can be used as fertilizer or bio-fuel.
Hydrocracking of vegetable oils, animal fats and other biological oil feedstock are involved in the production of Green diesel. These which possess the same chemical characteristics as the regular diesel. Distribution and use of Green Diesel requires no change in the infrastructure of the production unit or the engine that burns it. Gasoline version of Green Diesel is currently being developed.
Low quality or used vegetable oil can be processed into green fuels. The viscosity of vegetable oil fuel has to be reduced by heating it so that the pattern of its atomisation by fuel injectors is correct efficient combustion. Older engines that do not have electronic diesel unit injection system can burn direct vegetable oil. Hydrogenated fats and oils can be mixed with diesel in any proportion. Hydrogenated oils are straight-chain hydrocarbons with no oxygen, low aromatic and sulphur constituents and high cetane number.
Using some of the latest green fuels instead of burning the fossil fuels would not only be low on pockets but also help in reducing the damage to the environment.