Biofuels are fuels obtained from biomass (agricultural crops such as palm oil, sugar cane, soybeans, etc.) or from organic waste. The fuel generated is a liquid fuel that can be used in the engines of vehicles.
This energy source is considered non-renewable energy because the generation and recovery time of the fields is less than the consumption time.
The biofuels generated can be of two types:
- Bioethanol, a substitute for gasoline, produced from sugarcane, beet, corn, wheat and oats.
- Biodiesel, a substitute for diesel, produced by plants such as sunflower, rapeseed, palm or soybean.
Generations of biofuels
Since its inception, the production of biofuels has undergone different technological advances. Until today, there are already up to 4 generations of production of this non-renewable energy source. Each new generation aims to overcome the drawbacks of the previous generation. All generations have two common goals: not to harm the production of crops for food and to simplify the process.
In this way we distinguish the following generations of biofuels:
- First generation biofuels. It is about biofuels generated from food crops. The food crops are cultivated explicitly for the production of fuel.
- Second generation biofuels. These are fuels manufactured from various types of biomass. Any source of organic carbon is considered biomass. Biomass is derived from plant materials, but may also include animal materials. This non- renewable energy source should grow on land that can not be used to grow food effectively.
- Third generation biofuels. It is about generating biofuels through the use of algae. The production of algae to harvest oil for biofuels has not yet been carried out on a commercial scale. This type of fuel does not imply a decrease in food production.
- Fourth generation biofuels. Fourth generation biofuels are manufactured using non-cultivable land.
Origin of biofuels
This type of fuel was presented as an alternative to oil extraction and with the aim of reducing air pollution and climate change. Even so, the result was not what was expected and its use is being criticized by environmentalist platforms.
Problems with biofuels
At the environmental level, biofuels have the same greenhouse effect as fossil fuels and some pollute more. The lands where they are grown do not regenerate fast enough to meet the demand for this fuel, so it can not be considered a source of renewable energy.
To cultivate the raw material of biofuels, large areas of land are used, which leads to problems of deforestation, elimination or displacement of crops destined for food or pasture. This fact, added to the fact that they are generally grown in underdeveloped countries, accentuates the problems of hunger in the population.
At the energy level, they do not represent any improvement either. The Energy Return Rate (TRE) is less than 1 or very close to it, which means that the energy balance is zero or negative: it takes more energy to produce it than the one obtained from its combustion. As a reference, coal in thermal power plants currently has a TRE of 9, that of hydroelectric power is more than 11, and that of oil, in the 40s, was 100, that is, to obtain one hundred calories of oil it was necessary to invest a single calorie in obtaining and treating it.
Difference between biofuels and agrofuels
In principle, the Greek prefix bio (in Greek, bios, which means life, alive) of the word biofuel wanted to imply that it is a fuel formed from organic matter, as opposed to fossil fuels.
But not always this bio prefix has been added with enough rigor. Many brands have labeled their products as bio to indicate that they have been developed according to specific procedures that include ethical, ecological and environmental values. Currently, many people mistakenly associate the bio prefix of biofuels in this criterion.
For this reason, many environmental organizations use the term agrofuels, in reference to agriculture as the origin of these fuels.