Biomass is an increasingly popular term in our daily lives, but not everyone knows its true potential as a renewable energy source.
In the concept of power generation, this term Biomass It brings together all modern derivatives of living organisms that are used as fuel or to produce the same types of fuel.
From an environmental point of view Biomass It is the total amount of living matter present in an ecosystem or in a population, whether animal or plant. Thus, these two concepts are related, although they are somewhat different.
Simply put, we can say that natural solid waste and waste resulting from human captivity is called biomass, in other words, biomass is the by-product of livestock, agriculture, forestry, timber industry exploitation, etc.
The biodegradable portion of urban solid waste (household waste) is also considered biomass.
What is biomass energy?
Definition of biomass in energy generation
For the definition of biomass in the context of energy generation, conventional fossil fuels are not taken into account, although they are also derived from the vegetable and mineral branches (examples are mineral coal from the vegetable sector and oil and natural gas from the mineral sector), however, these are the result of several transformations that require several million years to occur.
Biomass can be considered a renewable natural resource, unlike fossil fuels.
How is biomass used and converted into usable energy?
Biomass is used directly as fuel or through energy production from pyrolysis, gasification, combustion or co-combustion processes of organic matter present in the ecosystem.
Methods of converting biomass into energy
We present the four ways in which biomass can be converted into energy:
Pyrolysis
during Pyrolysis technologyWhere the biomass is exposed to high temperatures without the presence of oxygen in order to accelerate the process of its decomposition. What remains from the decomposition is a mixture of gases, liquids (vegetable oils) and solids (coal).
Gasification
As in pyrolysis, here the biomass is also heated in the absence of oxygen, resulting in a combustible gas as the end product. This gas can still be filtered to remove some of the remaining chemical components. The main difference with regard to pyrolysis is the fact that gasification requires a lower temperature and produces only gas.
combustion
Here, biomass is burned at high temperatures in the presence of plenty of oxygen, producing steam at high pressure. This steam is generally used in boilers or to drive turbines. It is one of the most common forms today and has an energy efficiency of 20 to 25%.
joint combustion
The practice of co-combustion proposes to replace part of the mineral coal used in thermal-electric generators with biomass. In this way, pollutant emissions are significantly reduced.
Biomass performance ranges from 30 to 37%, making it a very attractive and economical option today.
Filter
Filtration is the process of converting solid biomass into mostly liquid products.
This process is divided into:
-
-
- Direct filtering: The reaction takes place in a reducing atmosphere of hydrogen or a mixture of hydrogen and carbon monoxide, and is therefore a form of pyrolysis. High pressures of 100 to 200 atm and temperatures of 400 to 600 °C are used. The biomass is crushed to the chosen metric particle size range and mixed with some solvent, to form a suspension containing 10% to 30% solids. The most common liquid is water, however, organic media can be used
- Indirect filtering: Production of syngas, CO + H2, by gasification and conversion to methanol or hydrocarbon using a catalyst.
-
Condensation
Biomass compression process consisting of applying pressure to a given mass of particles with or without the addition of binders or heat treatment. The raw material can be, for example, sawdust, charcoal particles or forest residues.
Products such as pellets, briquettes or biomass cylinders can be obtained from this conversion process.
How does a biomass plant work?
Biomass plants run on different types of fuel depending on where they are located.
Some biomass plants burn municipal waste or agricultural waste, while others burn wood harvested from forests.
The method of energy production is the same for all types of biofuels/biomass:
-
- Preparing biomass for combustion;
- Biomass is burned to produce heat to heat water.
- In turn, the water turns into steam that rises.
- The steam in its rising circuit causes the generator’s turbines to spin.
- In the final process, the movement of the generator turbines converts the energy into electrical energy.
Video – Biomass Plant Operation
Video – Converting Biomass to Electricity
Advantage of using biomass
Biomass is a renewable resource.
There are many benefits to using biomass energy, it has a low cost of acquisition, does not contribute to global warming emissions, and is less harmful to the environment than fossil fuels, thus reducing environmental risks.
Despite the obvious advantages of using biomass to produce electricity, there are also some disadvantages. Find out which ones are: Main disadvantages of biomass energy.
