Biofuel forms a part of the alternative sources of energy that have become popular and more usable over the course of the last few decades. They can be divided up into first, second, third and fourth generations, based on their time of invention.

First Generation Biofuels

Bioalcohols — There are chiefly three main types of first generation bioalcohols, ethanol, propanol and butanol, the last two being the less used ones while the first is the most popular bioalcohol. Bioalcohols are most commonly used as an alternative to gasoline in car engines, but certain types of fireplaces also have the use for them.

Biogas — Biogas is actually methane gas and it is produced when anaerobic microbes act on biomass. It is often collected from certain biological waste treatment facilities that fit the profile. Depending on the condition of the biogas, it can be used for electricity production, fueling a vehicle, water heating and much more.

Bioethers — These oxygenated fuels are popular as octane rating enhancers. Bioethers not only help the engine perform better and last longer, they also reduce harmful pollutant emissions from vehicles.

Biodiesel — It is extensively used in Europe, especially England. The biofuel is produced from food crops like mahua, mustard, hemp, algae, rapeseed, sunflower and many others. When compiled properly with mineral diesel, biodiesel can serve well as a car fuel.

Green Diesel — Although they serve the same function, the chemical composition of the green diesel is different from that of the biodiesel. Also, green diesel is not produced through transesterification, unlike biodiesel.

Vegetable Oil — Vegetable oil mostly serves as the primary material from which biodiesel is derived.

Syngas — Produced through a procedure which involves burning biomass in insufficient oxygen and combining carbon monoxide with hydrogen, syngas is another diesel replacement and its main use is as a car fuel.

Solid Biofuels — Solid Biofuels include mainly throw away byproducts like household garbage, agricultural waste, sawdust, mowed or cut grass etc, but wood, charcoal, non-food energy crops also are solid biofuels as well. A common problem with solid biofuels is the fact that they pollute the air a lot due to particulates and hydrocarbon emissions.

Second Generation Biofuels

Cellulosic Biofuels — biohydrogen, biomethanol, bioDME, biogydrogen diesel and many other forms of biofuels are derived from cellulose and they are categorized under the second generation biofuels.

Cellulosic Ethanol — It is a hard process but it makes it possible to use the food crops more for feeding human beings and animals and less for producing energy.

Myco-Diesel — The discovery of the roseum fungus has made it possible for scientists to try and use its ability to convert cellulose into hydrocarbons, in producing myco-diesel.

Third Generation Biofuels

Algae Fuel — Algae are greater yielders of energy than most food crops and they also reduce the pressure off the food crops and that too at a much cheaper price.

Algae Ethanol — Algae ethanol is unique in the way it is obtained. Most, if not all biofuels are obtained by using the living or non-living biomass to generate the fuel, but algae ethanol is a natural product of certain algae species itself.

Distillates — Jet fuel, gasoline as well as diesel can also be produced from algae through biocatalytic cracking and fractional distillation.

Fourth Generation Biofuel

Under this category, there is nothing new that needs to be explained because the category is differentiated from the previous generations on the basis of the mode of biofuel manufacturing. The modes and methods include gasification, solar-to-fuel, genetic enhancement and modification and pyrolysis among others.

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