Andrzej FRANKIEWICZ* – Liquid Fuels and Bio-economy Department, Automotive Industry Institute, Warsaw, Poland
Please cite as: CHEMIK 2016, 70, 4, 203–208
The civilization progress causes the increase in energy and propellants demand. Depleting natural sources such as coal, crude oil, natural gas, and changing world geopolitical situation caused, that the humanity started to turn to alternative energy sources. Biofuels (fuels resulting from the biomass processing) are a kind of these sources.
The first generation biofuels consists of biofuels produced from sugar, starch, vegetable oil or animal fat. This biofuels type includes: biodiesel, bioalcohols, biogas and pure vegetable oils. Controversies appear in connection with the fact that this raw material is a food for people and animals or it is used for food production.
The second biofuels generation consists of biofuels produced from raw materials, which are not used for food production like lignocellulose or solid municipal waste. This group includes inter alia biohydrogen, biomethanol or biodiesel produced from non-edible oilseeds.
The third generation biofuels are biofuels generated from plants modified by genetic engineering methods to improve biomass conversion into biofuels. Some authors  count biofuels produced from algae to the third generation biofuels, but it is not correct. As a result of various algae conversion processes, biodiesel and bioethanol are obtained.
There is a concept of the fourth generation biofuels, in which the key issue is the carbon capture and storage. CO2 formed in these processes is sequestered geologically (e.g. into declining oil fields), mineral (in the form of carbonates) or captured by crops, which reduce the greenhouse gases emission.
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