Types Of Biomass Energy
The rapid shift towards renewable energy has increased attention on different types of biomass energy. As organic material derived from plants and animals, biomass contains stored chemical energy that can be released through various methods. Through photosynthesis, plants first absorb energy from the sun and store them as different forms of carbohydrates. When plants are consumed by animals, this chemical energy is transferred to them and their waste upon excretion.
Different Types Of Biomass Energy
Categories of biomass, its sources, and conversion into different types of biomass energy
There exist three overarching types of biomass: Natural, residual and energy crops (a derivative of natural biomass). From these sources, different types of biomass energy can be released directly or indirectly. Direct conversion of biomass into energy such as heat occurs through processes like burning. Indirect conversion of biomass into energy such as electricity involves converting the raw biomass, like corn, into another source of biofuel or biogas, like gasoline, through processes like fermentation. The resulting biofuel or biogas is further burned or used directly as sources of power. Different types of biomass energy are thus produced according to the original biomass source and processes used.
The most common types of natural biomass are wood and animal waste. The primary process of obtaining energy from wood is through burning. The heat that is produced boils water inside a tank or boiler, releasing steam which is finally converted into electricity through generators or turbines. Types of biomass energy produced through combustion of wood are used for domestic purposes, such as cooking, heating and off-grid electricity generation, and industrial purposes such as powering factory machinery.
Animal waste is most commonly converted into biogas through decomposition in anaerobic conditions or environments without oxygen. Such waste contains chemical energy from microscopic organisms which consume dead plants and animals. In digestors, animal waste produces biogas, a blend of methane, carbon dioxide, and other trace gasses. Usually containing a high proportion of methane (about 50-75%), biogas is flammable, and therefore able to be utilized as an energy source. Such types of biomass energy are commonly used as fuel, producing electricity to power industrial plants, gas engines in vehicles or stoves for cooking.
Residual biomass contains biological remnants from industrial, farming or household activities. Sources include landfill waste, garbage (includes food waste and yard trimmings), food or beverage processing waste and wood waste. As with wood and animal waste, energy is extracted from residual biomass through similar processes of burning and conversion into biogas. Biogas can also be purified into natural gas and used to power vehicles. This is increasingly used in many countries to provide clean public transportation alternatives, especially with stricter mandates on global greenhouse gas emissions standards. Such types of biomass energy also power clean energy vehicles through fuel cells which chemically convert biogas into electricity.
Lastly, an increasingly common type of biomass are energy crops. These are selected plants intentionally grown for biomass energy production. The most common types of energy crops include corn, sugarcane, hemp, and soybeans. Energy crops are converted into alcoholic fuel through chemically breaking them down into fermentable sugars and then distilled into alcohol. Alcoholic fuel, also known as industrial ethanol or bioethanol, is primarily used as it is a significantly cleaner and more efficient alternative to petrol in vehicles. In addition to bioethanol, energy crops are also processed into vegetable oils to produce fuel in a liquid state, commonly referred to as biodiesel. Through a chemical reaction known as transesterification, glycerin is extracted from the vegetable or animal fat to produce two main components, glycerin (used in soaps) and methyl esters or biodiesel. Such types of biomass energy can be used in existing diesel engines with zero or minimal modifications.
With a growing transition away from fossil fuels, the types of biomass energy will only continue diversifying. Through continuous technological innovation, we can expect more types of biomass energy in terms of accessibility, affordability, and reliability.
Is Biomass Renewable
Is biomass renewable, yes it is. Biomass is considered a renewable energy source because its inherent energy comes from the sun and because it can regrow in a relatively short time. So looking at trees, this is the easiest explanation. Trees take in carbon dioxide naturally from the atmosphere. Once absorbed they then convert this into biomass. When a tree dies, it is either left to decompose or it is burned as fuel. Both of these release carbon dioxide of around the same proportions back into the atmosphere. if new trees are replanted to replace ones used for fuel, the thoughts are these new saplings & trees would absorb the carbon dioxide, thus making this a carbon neutral process.
If you want to read more about biomass energy, there’s a report here to download for free, titled Biomass energy overview.