The biofuel or biofuels are substances product mixture of organic matter (biomass), harvestable energy value provided with motors or internal combustion systems .
They are also known as ” agrofuels “, since most of them come from the use of products derived from agriculture, such as corn or cassava, and to avoid the positive feature of the prefix “bio-“, since they are also a source of pollution, although not as high as other energy sources . Although the important thing about these substances is their economic and safe origin, they are often mixed with other types of fuel to maximize their performance. Still, many countries place hope in biofuel development to alleviate or replace the consumption of traditional fuels , such as fossil fuels .
Most biofuels are obtained by fermentation , anaerobic digestion or transesterification of starches, sugars and vegetable oils, to obtain alcohols, ethers, gases and various forms of fuel substances. This means that an injection of energy is required in its elaboration, which in certain cases could exceed the energy capacity of the fuel obtained, so for the moment, biofuels are more a form of recycling than an energy solution .
It can help you: 10 Examples of Fuels
Examples of biofuels
- Biodiesel . The biofuel with the highest demand in Europe, is obtained from vegetable oils, animal fats or microalgae oils, and once mixed with mineral diesel, it can be used in any diesel combustion engine. Its emissions are less harmful than those of normal diesel, since it is a highly hydrogenated and oxygenated fuel, produced from vegetables such as soy, mustard, flax, sunflower, hemp, palm and others.
- Bioethanol . Produced, like most bioalcohols, by the fermentation of sugars or starches in organic matter from the action of microorganisms and enzymes, it is a high purity alcohol that can be used as an additive or substitute for gasoline in certain engines. It is obtained particularly from the fermentation of sugar cane, beets or even wine must, or various cereals. It is the biofuel with the highest production in the world (40,000 million liters in 2004).
- Green diesel. This type of biodiesel is produced through biological hydrocracking , that is, the breakdown of large molecules in vegetable oils into small hydrocarbon chains, useful for diesel engines. This occurs in the presence of very specific catalysts and high pressures and temperatures. Similar versions of biogasoline are said to be in development.
- Biofuel gasoline. There are numerous alternative gasoline projects underway, one of which managed in 2013, from certain strains of the Escherichia coli bacteria , to transform glucose molecules into a certain biogasoline that would not require mixing. Although these experiments still require a lot of work to become profitable in quantity, it is estimated that in the coming decades there will be surprising results in the area.
- Biogas. Obtained by anaerobic (oxygen-free) decomposition of organic matter, this hydrocarbon- rich gas is produced as well as a solid “digestate” that can be used as fertilizer. Biogas is combustible, fairly safe, and low-yield, but can be produced relatively easily from biodegradable waste, manure, or other agricultural residues.
- Syngas. It is a mixture of gaseous hydrocarbons with carbon monoxide and hydrogen, obtained through the partial combustion of organic matter and previous drying and polarization processes. The result is a fairly efficient fuel gas that can either be used to obtain other more complex biofuels or burned in an internal combustion engine.
- Biomethanol. Alternative fuel for internal combustion engines currently in use in China and in the racing car industry. Made from biomass , it is cheaper than ethanol, but more polluting and with lower energy density.
- Mycodiesel. The discovery of the fungus Glocladium roseum from the northern Patagonian forests, capable of converting cellulose into medium-length hydrocarbons very similar to those of diesel, allowed experimentation with this type of substance as a biofuel, using genetic technology and other similar microorganisms based on trying to create a profitable and easy to obtain mycodiesel.
- Cellulose ethanol. Using microbial cultures or waste from inedible products (which has the great advantage of not replacing food products towards the energy chain, abandoning the food chain), copying a bit the ruminants’ food process , capable of breaking down these sugars, but in a laboratory. This requires high temperatures and, at the moment, it has not been possible to produce in profitable quantities, so it is an investigation project.
- Algae biobutanol. Although it has a very low current yield, biobutanol is perfectly producible from sunlight and the fermentation of certain nutrients from seaweed. This method of converting glucose to butanol is not very efficient, so genetic methods are being sought to optimize the process and speed up obtaining the fuel.
- Biohydrogen . It is hydrogen produced by algae, bacteria and archaea, whose photosynthetic process is capable of producing the element instead of oxygen, in the presence of the enzyme hydrogenase . This resource is usable as a chemical laboratory supply, but it also contains great potential as a biofuel. The way to control this process and to manufacture the tons of hydrogen necessary to use it in a combustion engine is currently being studied.
- Hydrobiodiesel . Produced by catalytic hydrogenation of vegetable or animal oils and fats, it is completely compatible with conventional diesel, so it can be used as a fuel for ordinary diesel cycle engines. In this process, long chains of alkanes are obtained that are highly energy-efficient.
- Hydrobiokerosene . Prepared in turn from hydrobiodiesel, it is obtained by subjecting it to subsequent treatments (isomerization and fractionation) to isolate the hydrocarbon stream in its ideal ranges of crystallization and distillation.
- DMF (dimethylfuran) . With an energy density 40% higher than ethanol, comparable only to gasoline, this compound can be produced through catalytic mechanisms from glucose or fructose. Dimethylfuran (C 6 H 8 O) is chemically stable and, dissolved in water, does not pollute the atmosphere. Much current hope is pinned for the future of this compound