Biofuel: part 2

Second and third generation of biofuels as sustainable energy sources

2nd generation of biofuels

When people talk about the second generation of biofuels they usually refer to biofuels produced from food-unrelated materials. Plants grown specifically for this purpose make up the basis for this type of fuel. Inedible parts of certain food crops can also serve as the basis.

Jatropha oil is an example of this type of fuel. Conversion of the compressed oil into biofuel. The compressed oil can be processed into biofuel in a conventional manner, however the plant is not a food crop. The seeds of the are poisonous, therefore, it does not compete with food crops. Moreover, it can grow on very dry soil.

Another new development in the field of biofuel is making bioethanol from cellulose through fermentation. A process is now available to “crack” the cellulose from vegetable sources into fermentable sugars. This process allows to use the inedible parts of vegetable plants as biofuel. Such inedible parts can include straw, crop residues, woody crops and certain fibrous crops. This process does not evoke any fuel crop competition with food crops. Leftover products from the food industry serve as raw material for biofuel production.

Another development in the field of biofuels consists in making biogas from biomass. This biogas is subsequently used in power plants, where it is converted into liquid biofuels, such as biodiesel and bioethanol. BTL is the common abbreviation of this process, it stands for Biomass to Liquid. The end product of this process provides fuel for diesel engines.

Depending on the production method, the new generation of biofuels can reduce the emissions of greenhouse gases by up to 95%, as compared to fossil fuels. Realistically, the 2nd generation of biofuels can only come into large-scale production in 5 to 10 years.

3rd generation of biofuels

The term “third generation biofuels” remains a bit ambiguous for the time-being. Mostly, people use this term to emphasize that a certain biofuel production process is more advanced than those considered “2nd generation”. Often, this means biofuel production from algae. Algae as biofuel has the great advantage of not competing with food algae. They are specially cultivated to serve as biofuel.

Biofuel - algae

Currently algae cultivation for energy purposes remains rather undeveloped. The cosmetic industry is responsible for most of the algae cultivation. Algae contain many lipids and are therefore very suitable for skin creams and other type of skin care products. Other industries involved in the algae cultivation include animal food producers, as well as the producers of Omega-3 fatty acids supplements.

However, scientists are currently performing a lot of theoretical and experimental investigations to find out new ways of converting algae into biofuels. Lipids are the key elements here, as they constitute raw materials for the production of biodiesel. Algae with high concentrations of lipids are thus the most suitable for biofuel production. One hectare of green algae produces about fifteen to twenty tons of biodiesel annually.

There are several techniques of algae cultivation and the consequent biofuel production. Most of these techniques are, however, still under development. Therefore, this source of biofuel is not yet widely being used. Nevertheless, it seems to be very promising, with more and more research conducted each year.