The escalating use of fossil fuels, rising energy demand, fluctuating fuel prices, and rising greenhouse gas emissions are just a few of the concerns driving a shift in interest from fossil fuels to biofuels. Biofuels are carbon-neutral energy sources because the CO2 released by their burning is used by plants during photosynthesis, resulting in no net increase in CO2 levels in the atmosphere. Biofuels are liquid or gaseous fuels made mostly from biomass that can be used to replace or supplement diesel, gasoline, or other fossil fuels in transportation, stationary, portable, and other uses. Biofuels are divided into three groups in general. They are as follows:
First-generation biofuels are manufactured with standard technologies from sugar, starch, vegetable oil, or animal fats.
Second-generation biofuels- such as cellulosic biofuels and waste biomass, are made from non-food crops (stalks of wheat and corn, and wood).
Third-generation-biofuels- Biofuels of the third generation are made from microorganisms such as algae.