We explain what biofuels are and how each one is obtained. In addition, the advantages they present and types of biofuels.
What are biofuels?
Biofuels are those fuels that are obtained from biomass or organic waste (hence its name). The biomass is organic matter from a plant or animal.
Biomass is part of the set of renewable energies , which are found in limited quantities in nature and are produced in slower and longer periods than what it takes to consume them. Diesel and gasoline, for example, are made from fossils of plants or animals that take millions of years to conform while consumption is immediate.
Biomass is a source of energy that, since the invention of automobiles (at the beginning of the 20th century) has become indispensable. It is used, in the industrial field, for the generation of electricity and heat . It is very common to use it, then, for home heating.
Over the years, the price of biomass has risen considerably , especially from the concerns that have arisen worldwide as a result of the emission of CO2 (Carbon Dioxide) and its impacts on the environment environment . Despite this, environmental protection advocates also question the use of biomass since its production results in deforestation.
Within the biofuels from the plant world (which are the most used especially for the operation of cars), they can be differentiated into two large groups:
- Bioethanol This energy source is produced from oats, corn, wheat, beets or sugar cane and is used instead of gasoline.
- Biodiesel This biofuel, on the other hand, is used instead of diesel and is made from soybeans, palm, rapeseed or sunflower.
How are biofuels obtained?
Biofuels are obtained from organic waste or from biomass. They are the result of different chemical or physical processes that transform these wastes or matter. Here are some examples of how you get them:
- Biogas It is the result of a mixture of gases that decompose organic matter through bacterial actions.
- Biodiesel In this case, different chemical processes are used , such as transesterification from methanol or ethanol (the most commonly used). In this process the fat molecules are converted into esters.
- Bioethanol This biofuel, on the other hand, is obtained from the fermentation of non-crystallizable monosaccharides in the manufacture of both beet and sugar cane. It can also be obtained from the hydrolysis or fermentation of the starches of certain cereal grains. To carry out this fermentation, yeast is used. The process of obtaining this biofuel has three key stages: fermentation, distillation and dehydration.
Advantages of biofuels
While it is true that environmental specialists warn about the consequences of using biofuels, such as deforestation (including Greenpeace), one of the main advantages of biofuels is the reduction of carbon dioxide emissions, in relation to fossil fuels. According to different studies, 80% of biofuels reduce carbon dioxide emissions by 30%.
In addition, another benefit of biofuels is the production of soot and suspended particles , which are much lower than those of other energy sources and that affect the respiratory system of people and animals.
Finally, there are those who, when comparing the relationship between invested and obtained energy, ensure that the results are much more auspicious in the case of biofuels than fossil fuels.
Types of biofuels
There are different kinds of biofuels, if you consider what their source is. In this sense we can find the following types:
- Primary They are those biofuels that come from firewood, landfill gases, crop or animal residues. The impact (positive or negative) on the environment will depend on the procedures used to obtain energy from these materials.
- Secondary These are those energy sources that are classified according to their generation. In this sense, the following classes are found:
- First generation They are those biofuels whose process of obtaining does not require the hydrolysis of the carbon source (for example, bioethanol and biodiesel). The raw materials used are all sources of food.
- Second generation All sources other than food , so as not to put food safety at risk.
- Third generation Those raw materials that are vegetable, but not used as food.
- Fourth generation Although this category is in full development, biofuels produced from bacteria that have been genetically modified are located here , for which carbon dioxide is used.