The term “biofuels” indicates to any person, knowledgeable or not on the matter, that it is some form of energy from nature, either from the use of decomposing organic matter resources or its processing under natural conditions. Perhaps without knowing it by name, this has been humanity’s quintessential energy source since the discovery of fire, when using firewood and charcoal for various domestic uses. Today, this fuel is used primarily in areas of extreme poverty for cooking.
Despite its widespread domestic use, biofuels began to gain public notoriety in the framework of state planning related to energy security, and the fight against climate change, since these are presented as a potential alternative to fossil fuels; however, its implementation has been somewhat controversial as it has a direct environmental impact on deforestation and food security in the world. In this article, the various technical considerations and the existing yields in the use of this energy source will be evaluated.
Technically speaking, biofuels are those carriers of energy stored by biomass, considered a renewable source as it is a transformed form of solar energy 1 . These are classified according to their origin and type. The first categorization corresponds if the fuel is solid, liquid and gaseous, which is called biomass, biodiesel/bioethanol and biogas, respectively. The classification according to the type, groups them between those biofuels without elaboration (primary), and those processed (secondary).
Biodiesel vs. bioethanol
As previously stated, the rise of biofuels in the modern era came with the perception that these could be an alternative to fossil fuels, especially in the transport sector, which comprises 23% of CO 2 emissions by 2015 . The question arises, between biodiesel and bioethanol, which one would you use for your daily use? You may be surprised by the correct answer, and it is… “it depends” . You’ll see why.
Biodiesel, as its name indicates, is the biofuel that is mixed with residual petroleum #2, or diesel, or diesel as it is known in Spain. It comes from vegetable oils obtained from oilseed crops, such as rapeseed, sunflower, palm or soybean. Bioethanol, on the other hand, is an alcohol that is mixed with gasoline and is obtained from crops rich in sugars such as sugar cane or beets, or cereals such as corn, wheat, barley or rye. through a process of fermentation and subsequent distillation. That is why the choice will depend on the type of engine that your vehicle or application has.
It is necessary to highlight that biofuels are used as additives to fossil fuels, since there are limitations in the engines regarding the amount that can be incorporated into the mixture that does not impair their proper functioning. Commercially, they are identified with a letter (E – bioethanol – and B – biodiesel-) to indicate the type, followed by a number with the percentage in the mixture. For example, an E5 is a biofuel with 5% ethanol and the rest gasoline. This is followed by E10, E25 and E85, the one with the highest percentage of ethanol used. In the case of biodiesel, B5, B10, or B20 are used. The higher the percentage incorporated into the mix, the theoretically lower amount of greenhouse gas emissions released into the environment.
However, since biodiesel and bioethanol come from various crops, it is to be expected that there will be a kind of yield, or efficiency, according to the type of raw material used. That is why the energy used in the obtaining, processing and distribution of the different sources has been technically evaluated, and it has been contrasted against the energy delivered by them.
In the case of ethanol produced from crops, the estimated balances show that when corn is used as the raw matrix (USA as the main exponent), the relationship between unit of energy obtained per unit of energy invested is a little less than 2 to 1. , but when sugar cane is used (Brazilian case) it rises between 2-8 to 1. For biodiesel, using palm oil produces between 8 and 10 additional energy units 1 . If it were your option to choose, which would you use?
Threats to Food Security
Although it is true that the theoretical benefits of using biofuels are considerable, in practice they have brought substantial social and economic consequences. By coming from the raw material of the crops, mono-production is being promoted, and the consequent expansion of the agricultural frontier, especially in third world countries, resulting in deforestation, the destruction of ecosystems, among other environmental impacts. In the case of the United States, with a bet on corn as a raw material (of low yield, it should be noted) it is affecting a direct input of the human diet, with the consequences already felt for the planet’s food security.
In conclusion, biofuels are an alternative to the use of fossil fuels both in reducing the emission of greenhouse gases in the transport sector, and in the energy sovereignty of nations, as long as the raw material used has an appreciable yield. , is obtained from decomposition processes or another that does not threaten the planet’s food security, and deforestation is not encouraged. If these considerations are not taken into account, we will indeed manage to reduce the indicator of CO 2 emissions from vehicles to a minimum, but only because the emissions resulting from the slashing and burning of virgin spaces were not considered in the equation.
Published in: Venezuelan Commodities Magazine, 20th Edition. pp 20-21. ( See publication )
- FAO. 2008. Biofuels and Agriculture: Technical Overview. Retrieved from: ftp://ftp.fao.org/docrep/fao/011/i0100s/i0100s02.pdf pp. 11-19
- European Comission. 2016. Trends in global CO2 Emissions. Retrieved from: http://edgar.jrc.ec.europa.eu/news_docs/jrc-2016-trends-in-global-co2-emissions-2016-report-103425.pdf . Page 35