The biomass, in ecology, refers to the total amount of living matter contained in an individual, a rung of a food chain, a population or an ecosystem, expressed as weight per unit volume. 10 Examples of Biomass.
On the other hand, biomass is also the organic matter that is generated by a biological process, whether spontaneous or provoked and which has the properties necessary to become a fuel energy source. We could call this last meaning “ useful biomass ” since its area of interest is specific to obtaining biofuels (agricultural fuels).
This term has become more relevant since the boom in biofuels, necessary as an alternative to fossil fuels and its fluctuating market. However, the “organic matter” necessary for biomass is often confused with living matter, that is, with the one that integrates living things like trees (despite the fact that much of the bark that supports them may be, indeed dead). 10 Examples of Biomass.
It is also a mistake to use the term biomass as a synonym for the potential energy that said organic matter contains, more than anything because the relationship between the amount of usable organic matter and the energy that can be obtained from it is variable and depends on many factors.
The “useful” biomass
Biomass is used to obtain energy. For this, it is based on taking advantage of the processes of decomposition of organic matter in controlled environmental conditions, in order to 10 Examples of Biomass obtain hydrocarbon mixtures of energy potential, especially when feeding internal combustion engines, such as those of a car.
We can identify three types of useful biomass:
- Natural biomass. The one produced without any human intervention, such as the fall of the leaves in a forest.
- Residual biomass. It is the waste or by-product of other economic activities, such as agriculture, livestock, forestry or the food industry, or even the recycling of oils.
- Energy crops. Whole crops destined to obtain biofuels, focused on some type of vegetable or fruit tree whose energy power is high.
Advantages and disadvantages of biomass
The use of biomass as fuel has both positive and negative aspects:
- It is less polluting. Compared with petroleum and its derivatives, or coal, agrofuels generate low amounts of CO 2 and less environmental damage, although this does not mean that they are truly ecological fuels.
- Take advantage of residual matter. Much of the material that is normally going to be thrown away or decomposes uselessly has a certain energy value if it is used as a biofuel raw material. That also makes these relatively inexpensive and easy to obtain.
- It is not as effective as other fuels. Compared to fossil fuels, its performance is insufficient to be, at the moment, an effective alternative to the world energy demand.
- It involves ethical dilemmas. More than anything related to the diversion of food (corn, fruits, grains and cereals) from the food industry to the energy industry, which is more important to obtain fuel than to feed the hungry population.
Examples of useful biomass
- Firewood. A classic example of the use of organic matter is the collection of firewood to burn and thus obtain heat, both to heat a home through fireplaces, and to fuel a fire in which food is cooked. This method dates back to time immemorial and still persists among human customs.
- Seed husks and nuts. These residues from the ingestion of food products are commonly discarded in the garbage, but have a not inconsiderable fuel value. In many rural homes it is stored and used to fuel fires, or even to obtain vegetable oils for lubrication.
- Food remains . The organic matter left over from our meals has a relative energetic potential, not only as food for compost processes and soil fertilization, but also in obtaining biogas through anaerobic digestion processes (without the presence of oxygen). The bacteria that carry out this process produce high levels of methane, similar to what happens in our intestine, which makes biogas highly flammable.
- Beets, sugar cane, corn. Fruits rich in sugars, such as cane, beets, corn, are usable in obtaining bioethanol, through a fermentation process similar to that of obtaining liqueurs, since it produces a hydrated alcohol. 5% of water is removed from said alcohol and an energy-usable fuel, similar to gasoline, is obtained.
- Stems, pruning waste, wood and other greens . In the body of plants, sugars such as cellulose, starches and other carbohydrates are stored as a result of photosynthesis, which are usable as biomass in processes of conversion to fermentable sugars to obtain biofuels. Many of these residues are collectible without sacrificing food, since many plants must be pruned, replanted or uprooted after bearing fruit and this material is usually discarded.
- Corn, wheat, sorghum, barley and other cereals . Similar to obtaining beer, these cereals and vegetables are extremely rich in starches, which are complex carbohydrates from which bioethanol can be obtained through alcoholic fermentation.
- Sawdust or sawdust . A possible source of biomass is found in the huge amounts of powdered wood disposed of by sawmills and the wood industry as such. All this dust has the same fuel potential of wood, in addition to being a source of cellulose to obtain fermentable sugars in bioalcohols.
- Wine must and sulfur wines . Decomposed wines and must residues from its manufacture are sources of biomass, since they provide raw alcohols to which the sulfur dioxide (SO 2 ) must then be removed , its methanol charge (corrosive to combustion engines) and finally can be used for get bioethanol.
- Livestock waste . Livestock farming is an important source of organic matter that can serve as biomass, such as the excrement of ruminants (whose exclusive diet of vegetable cellulose is promising) or even fats left over from animal use.
- Household residual oils . A source of liquid biomass is the oils that we discard after cooking, mostly made from sunflower, canola, even olive, in short, vegetable products. The production of biodiesel from them requires filtering of solid waste, transesterification stages to convert triglycerides into methyl esters, and the addition of methanol. After neutralizing the pH of the result, biodiesel and glycerol are obtained. The latter is removed and is usable for the soap industry, while biodiesel is purified and used as fuel.