By Aniket Bose. Edited By Arjun Chandrasekar.
Biomass energy (energy from living things) has been used since the time of cavemen when they first made wood fires for cooking their food and keeping themselves warm during the prehistoric time period. Biomass is organic, which basically means that it is composed of living organisms, such as animals and plants. The most popular biomass materials used for energy are wood, plants, and waste; these are called biomass feedstocks. Another benefit of biomass is that it can also be used as a non-renewable energy source.
How Biomass is Converted into Energy
The main process of how biomass can be used as energy is for it to be burned by thermal conversion. The energy that is generated from biomass is derived from the sun. The process of thermal conversion requires heating the biomass feedstocks to burn and dehydrate the biomass. The most common biomass feedstock raw materials for thermal conversion consist of paper scraps, lumber mills, and municipal solid waste (MSW). There is one major detail when it comes to burning biomass: it has to be dried up before it can be burned, and this chemical process is known as torrefaction. During torrefaction, biomass is heated up to 320 degrees (Celcius) so that it dries out entirely and loses its capability to absorb any form of moisture. In this process, it also loses roughly 20% of its mass, but it still maintains 90% of its energy. The energy and mass that is lost in the process of drying out biomass can again be used as fuel in the torrefaction process. In torrefaction, biomass becomes a very dry and blackened material. From there, biomass is compressed into briquettes and these biomass briquettes are highly hydrophobic, which means that they repel water. Since biomass briquettes are hydrophobic, this allows them to be stored in areas with a lot of moisture and they also have a high energy density which makes them easy to burn during co-firing or direct firing. The majority of biomass briquettes are burned directly, as the steam that is produced during the process generates a turbine, which is then used to turn on a generator and in the end produces electricity. When biomass is co-fired, it is usually burned with fossil fuel. Co-firing biomass is good for the environment as it gets rid of the necessity for new factories to produce biomass. This helps in reducing the amount of carbon dioxide and other greenhouse gases being released into the atmosphere.
In short, biomass is a plant or animal material that is used as fuel for producing heat and electricity. The most common types of biomass include wood, crops, forest waste, etc. Since biomass can be used directly as fuel, some people interchange biomass with biofuel. There has recently been a surge of usage of biomass fuels for transportation and electricity in multiple countries as they have been trying to avoid emissions of carbon dioxide by the use of fossil fuels. Plants are able to produce biomass through the process of photosynthesis. Biomass has many everyday uses and is a complex, yet crucial topic to understand in today’s world!