What is Biomass?
Biomass comprises all renewable organic substances, both animal and vegetable. Biomass energy comes from the energy stored by living organisms. In the first place, plants use photosynthesis to harness solar energy to produce organic substances; next, animals incorporate and transform this energy by feeding on plants: the products of this transformation, considered residues, can be employed as an energy source.
Types of Biomass
There are different types of biomass which can be used as energy sources. These can be divided into three: natural, dry and humid residues and energy crops.:
- Natural Biomass: This is produced by Nature without human intervention. The problem presented by this biomass is the necessary management of the acquisition and transport of the raw material to the production site.
- Dry Residual Biomass: These are residues (woody and herbaceous), considered by-products but which can be exploited to produce energy, left by agriculture and livestock, forestry and wood processing and agro-industrial activities, amongst others. Sawdust, almond shells, wine-press residue, orchard prunings etc. can be considered as examples.
- Humid Residual Biomass: Biodegradable waste such as urban, industrial and agricultural (mainly purine) residual water is included in this category.
- Energy Crops: These are crops raised with the sole aim of producing biomass for fuel. These crops can be divided into:
1. Existing crops such as cereals, oilseeds, beet, etc.
2. Forestry ligneous-cellulose plants (willow, poplar, etc).
3. Herbaceous ligneous-cellulose plants such as Cynara cardunculus.
4. Other crops such as Jerusalem Artichokes are raised with the sole aim of producing fuel. Some examples are cardoons, sunflower when raised to produce bio-fuels, miscantus, etc. - Bio-fuels: recycled oils, wheat, maize, sunflower, artichoke, etc.
Advantages
- Biomass is a sustainable and non-polluting energy source.
- It reduces dependence on fossil fuels and avoids the problems deriving from their use.
- It helps to keep forests clean and to reuse industrial by-products.
- For the owners of the facility: the energy bill is reduced as less energy has to be acquired externally.
- For society as a whole: the use of biomass provides numerous environmental and socio-economic advantages as do all renewable energies.
Within the domestic sphere the use of the latest biomass furnaces may be highlighted: totally automatic and pellet-fed, they out-perform fossil fuel systems economically (their low cost obtains significant savings), and in convenience as they are odourless and leak-proof. They are the ideal complement for a thermal solar facility. In addition, State subsidies are available.
What is a Pellet?
Wood pellets are small cylinders of compressed sawdust proceeding from dry chips and sawdust; they are formed by high pressure applied through a matrix without any kind of additive (the lignin present in the wood is a natural agglomerate) with very low humidity. The calorific value of 2.3 Kg of pellet is equivalent to a litre of gasoline or approximately 1 m³ of gas. Since the pellet is composed only of wood, it has a neutral balance of CO2 emission (this means that the CO2 released in combustion is the equivalent of that absorbed by the tree's growth and which will be absorbed by the tree which grows in its place). Thus heating with pellets helps in the reduction of greenhouse gasses and collaborates in meeting provisions of the Protocol of Kyoto.
Advantages of the Pellet
ECONOMIC
- The calorific value of 2.3 Kg of pellet is equivalent to a litre of gasoline or approximately 1 m³ of gas. Since the pellet is composed only of wood, it has a neutral balance of CO2 emission (this means that the CO2 released in combustion is the equivalent of that absorbed by the tree's growth and which will be absorbed by the tree which grows in its place). Thus heating with pellets helps in the reduction of greenhouse gasses and collaborates with meeting provisions of the Protocol of Kyoto.
- The use of pellets is subsidised.
- Using pellets, you are not subject to the continual price fluctuation of other fuels.
- The added value remains in your region since they are produced locally, strengthening the economy and creating new jobs.
SAFETY
- Stored pellets do not produce risk of explosion, they are not volatile, are odourless and do not give rise to leaks.
- The pellet is a non-toxic fuel with no health risks.
CONVENIENCE
- For the same calorific value, pellets occupy a third of the space occupied by solid wood.
- The physical properties of pellets allow them to behave as a fluid, which means that transport, deposit refilling, combustion and cleaning can be totally automated.
- The combustion of pellets hardly produces any smoke or fumes, in contrast to non-renewable fuels. ECOLOGICAL.
- They are a renewable energy source with a neutral CO2 balance.
- The combustion of pellets is far more efficient that that of firewood, and thus emissions are kept to a minimum.
- Since they contain no sulphur, they reduce the incidence of acid rain.
- Residues from pruning and forest clearing are used to make pellets, and thus the residue is re-valued: this encourages the care of forests, creating better habitats for wildlife and avoiding bush-fires.
- The ash produced by combustion of pellets is minimal due to its high efficiency, is totally biodegradable and even makes a good fertilizer.
