What is biomass?
Biomass is that organic matter of vegetable or animal origin, including organic waste and waste, which can be used as energy. Plants transform the sun’s radiant energy into chemical energy through photosynthesis, and part of this energy is stored in the form of organic matter .
The following is currently accepted as the definition of biomass:
“Biomass is considered a group of renewable energy products and raw materials that originate from organic matter formed by biological means.”
Biomass as an energy source
Since ancient times man has used biomass as an energy source to perform his daily tasks. When the use of fossil fuels began to gain strength, the biomass was relegated to a lower level, where its contribution to primary energy production was insignificant. At present, due to various factors, detailed below, there has been a resurgence of biomass as an energy source.
The factors responsible for favoring biomass as an energy source are:
- The rising price of oil.
- The increase in agricultural production.
- Need to look for alternative uses to agricultural production.
- Climate change.
- Possibility of using scientific and technical knowledge to optimize the process of obtaining energy.
- Favorable economic framework for the development of plants that use biomass as fuel, thanks to the production subsidies received by power generating plants with this source.
- Regulatory difficulty in developing other types of projects, leaving biomass as the most reasonable alternative to make an economic investment profitable.
Ten percent of the world’s energy demand is met by biomass. That alone shows how much technical and economic potential there is in bioenergy in the form of firewood, charcoal or manure. Energy from biomass – this means using agricultural and forestry residues and specially cultivated energy crops to generate electricity, heat and fuels.
Biomass certainly has disadvantages – but above all advantages. In order for the latter to be ecologically and socially sustainable, the use of biomass needs globally valid rules.
Advantages of biomass
1. Is considered to have zero carbon emissions
What does this mean? Thermal biomass comes mainly from plants and trees, and in all cases there has been an absorption of CO2 for its generation, so when these plants and / or trees, among other sources of biomass, are transformed into pellets, chips or just firewood to burn. The CO2 that is generated is equivalent to that initially absorbed, creating a closed cycle without extra CO2 generation. This is perhaps the biggest and most important advantage of energy from biomass.
Since it is a cycle, the following generations of plants absorb carbon over and over again, so that a balance is maintained between the amount of carbon that biomass fuel releases into the atmosphere and the amount that plants convert into cellulose . For this reason, fuels from biomass are considered “not contributing” to global warming, and are considered clean fuels. Each time the fuels derived from the Biomass are burned, from any of its origins, the CO2 produced returns to the forests or vegetation sources and is used in photosynthesis to continue its cycle
It is a source of renewable and abundant energy
Throughout the planet there is the possibility of accessing biomass sources such as clearing trees, crop remains, manure and organic waste. Over the course of a year in which all these sources are transformed into biofuels, equivalent amounts are being generated in crops, farms and cities. The pace of transformation resembles the pace of crop and harvest growth, and can be as short as a few months in some cases. Biomass is available in large quantities, both on land (forests, landfills, etc.) and at sea (algae that reach our shores).
Therefore, in general, large transport infrastructures are not necessary to take them to their destination. Therefore, work is being done to encourage the creation of small centers for the transformation of biomass into fuel, close to its origin, and also close to its consumption. The main advantage offered by the use of biomass as a source of energy is its characteristic of being renewable. Because it uses as primary source organic waste from agricultural activities or city garbage. Whether in the form of unprocessed waste, pellets, biogas or biodiesel; Biomass is unlimited, since living beings can never stop producing waste.
It is an important component of the energy mix
According to statements by the director of Innovation and Technology of the International Renewable Energy Agency ( IRENA ), Dolf Gielen: “A biomass based on waste and more efficient technology could make sustainable bioenergy a decisive actor in the global energy mix, reducing air pollution and helping to save lives. ” According to this agency, the global demand for biomass as a source of energy could reach 108 exajulios in 2030, an amount equivalent to 20 percent of the total primary energy supply and 60 percent of renewable energy consumption.
Contributes to reducing the dependency on fossil fuel
Spain as an example is a country deficient in fossil fuels. The little coal they have left is very expensive to extract and the few remaining farms are economically unviable, and we could say that the only reason for their subsistence is to avoid the economic deterioration of the areas where it is still exploited. On the contrary, it is a country with a great potential for renewable energies, and also for biomass, since there is a large usable amount of it for energy generation. Some experts point out that taking advantage of this potential would contribute to reducing the energy dependence of fossil fuels. And consequently to improve our total trade balance.
Creates jobs and promote growth in rural areas
According to sources in the sector, it is estimated that, for every thousand inhabitants that use biomass in an urban nucleus, thirteen stable jobs are generated. This job creation especially affects the development of the economy of rural areas, where biomass is mainly found (forest cleaning, crop residues, animal farms, purification of domestic sludge, etc.) that can be used as fuel . A major problem of small and medium-sized agricultural activities is the final disposal of waste and its use. For example, in many places in South America the rice husk once processed is burned in large quantities and in conditions of absence of air. This causes black smoke to occur, signaling the presence of carbon monoxide and other polluting gases.
Biomass technology gives farmers and ranchers the opportunity to use this waste to produce gas that they can use for different purposes. In addition, rice mills and other grains could use the husk of these products in order to generate the heat necessary for their drying process, as some industries that take advantage of part of their waste do as in the case of dedicated companies to the processing of olives or farmers. In this way, biomass would be used much more efficiently, and toxic emissions of Carbon Monoxide would be avoided and replaced by CO2, which if re-absorbed by plants and trees.
- Adjusted price – economic
The use of the energy contained in biomass can be considered economical compared to oil or coal. According to producer estimates, it usually costs about a third of fossil fuels to obtain the same result. This means that if your heating depended on biomass , you could save every year a third of the cost of heating it with diesel, which is a great saving.
Allows to face by improving economic competitiveness
Energy poverty is one of the great obstacles to the social and economic development of the most disadvantaged. According to FAO estimates, it is estimated that about 1.4 billion people in the world do not have access to electricity, or have very limited. In many developing countries, the high cost of fossil fuels takes more than 10% of GDP, and makes conventional energy increasingly inaccessible. That is why the use of this resource, which until recently or even in some areas today is considered a waste and unused, could improve the economic situation of many countries or areas that lack other resources, and thus improve the quality of life of many millions of people.
8 . Cheap resources
Another advantage of biomass energy, far from being a disadvantage for businesses, is that this type of energy uses inexpensive resources, which are available in large quantities. These can be of vegetable or animal origin. The organic materials are then recovered for further exploitation. It could be :
- Of wood extracted in forests ,
- Plant waste produced by agriculture (leaves, straw, stems, etc.),
- Food waste generated by industry or households,
- Manure harvested on farms …
Wood occupies a significant part of the energy of biomass. Harvested in the forests, the wood from trees is exploited for up to 60% of what grows annually. Forests therefore have time to regenerate. This undeniably constitutes a major advantage of biomass energy.
9. It reduces garbage in landfill
The generation of waste is a problem that society must face. Both citizens and industries, we generate waste every day, and the fate of most of them is the landfill, with the negative impact on the environment that this practice implies. However, we can reduce waste by 60% to 80% by sending them to biomass incinerators. Four tons of waste have the same energy as a ton of fuel,” says Pal Mikkelsen, director of the Waste-to-energy agency -basura for energy, in Spanish-, in Oslo and a kilogram of food waste produces half a liter of fuel. In Sweden of the total waste generated, only 4% reaches landfills, while the rest that is not recycled or reused.
Disadvantages of biomass
As we have commented initially, there are also drawbacks that we must take into account, and which we list below. Incineration can be dangerous by producing the emission of toxic substances. Therefore, filters must be used and combustion carried out at temperatures greater than 900 ºC. There are not too many suitable places for advantageous use.
1. Biomass crops
In some areas where biomass is constituted as a considerable energy industry, some farmers have begun to cultivate biomass-oriented species. This means a decrease in agricultural production related to food for human consumption. Which in turn would mean a shortage of them. This is a mistake, and the really good thing about biomass is the use of agricultural remains or forest cleaning, not the change of crops that can reverse other problems.
2. Difficulty and contamination in processing and handling
In order to obtain fuels such as biogas or biodiesel, chemical processes are used, which many associations in defense of the Environment, consider generating waste with a high content of Nitrates and Sulfates, which when used by the same farmers who are dedicated to these biomass crops, they are contaminating the lands where they are grown and therefore the aquifers, which is continuing the problem that our countries already suffer from the use of industrial fertilizers in the last 60 years. Also, this is a relatively complex and a bit dangerous process to handle. If this gas is accidentally released into the atmosphere, it would mean high levels of pollution, since the methane (CH4) it contains is a greenhouse gas 20 times more powerful than CO2.
3. Low calorific value (energy density)
This disadvantages of biomass energy, although not worrying, is that both it and its derivatives have a lower energy density than fossil fuels, a lower calorific value. This means that more storage space is needed, that is, more kilos or liters of biomass or its fuels are needed, than oil or its derivatives for the same amount of energy. Although this is not so relevant since the resource is almost always generated constantly and it is not necessary to store it.
4. It can cause exploitation of the forest
First of all, to produce electricity or heating using biomass energy, it is essential to be attentive to the use of natural resources. This is particularly true for wood from forests, which can quickly be used up if its exploitation is not controlled. To avoid the exhaustion of available wood stocks, combustion biomass power plants use other types of biomass. To function, they use, among other things, straw, sugar cane or even coconut husks. The latter come from agricultural plant waste.
5. The cost can be high
The other disadvantage of biomass energy is its cost, which tends to increase. The combustion or methanisation process can be expensive, the price of the energy thus produced depending on the operating costs of the power stations. The higher the latter, the more expensive the electricity produced. In addition, the expense for the transportation of resources is not less, it depends in particular on the price of the fuel used for transport.
6. It produces CO2
Biomass is considered to generate CO2, and therefore polluting, which constitutes a major drawback for the energy of biomass. In reality, the amount of carbon dioxide it releases corresponds to the amount of CO2 that was previously absorbed by plants which are then used as an energy resource. So it’s an endless cycle that occurs.
7. Huge arable land necessary for energy crops
The cultivation of energy crops in limited areas competes with food production and the need to protect natural ecosystems. If rainforests are cut down for the cultivation of energy crops , the total energy production from biomass can also be harmful to the climate.
Due to the energy-intensive cultivation practices, this also applies to the production of agrofuels from corn and wheat in the USA and from rapeseed in Germany, for which a fifth of the arable land is already used in the USA and twelve percent in Germany.
8 . Production of biomass has been extremely inefficient so far
The cultivation and production system leads to higher emissions of greenhouse gases than the use of fossil fuels! In many countries, prices have also risen due to the use of corn and wheat for the production of fuel. The poorest of the poor suffer above all: Too high prices are the main reason for hunger in the world .
The use of biomass is therefore not automatically sensible, but needs rules. Smart energy generation from biomass means minimizing its disadvantages and using the advantages for a sustainable future.
Biomass energy with its advantages and disadvantages, an alternative to fossil fuels
At a time when ecological concerns and CO2 emissions are at the heart of the debates, biomass, with its advantages and some disadvantages, is essential as a new energy to be explored for the actors of the sector, who are always looking for more to bet on renewable energies, and in particular photovoltaic energy, driven by solar OA , and wind energy.
The organic materials used absorb the CO2 mass produced by fossil fuels. Plants, trees and even plantations used as an energy source in biomass power plants play a major role in regulating the CO2 emitted.
However, oil, coal and even gas produce significantly more CO2 than plants are able to absorb. We can thus observe an accelerated growth of plants, which is largely due to the high level of CO2 present in the Earth’s atmosphere.
By developing the energy of biomass, which undeniably has more advantages than disadvantages, it would also be possible to reduce the production of methane, which is another greenhouse gas.
The use of biogas, generated by the fermentation of biomass materials, to generate electricity would also allow the use of other waste. This would be the case, for example, for waste collected from landfills, sewage sludge or household waste.