Bioenergy is renewable energy harvested from organic materials called feedstocks. Biomass can be obtained from wood, food, and urban waste, grains, crops, animal byproducts, forest residues, etc. Bioenergy is currently used to replace fossil fuel energy generation, plastics, chemicals, lubricants, as well as produce biodiesel and cellulosic ethanol. Biomass is a resource available in every household and is also used for industrial purposes applying innovative technologies.
Bioenergy is a form of renewable energy, which comes from living or recently living organic materials known as biomass. To put it simply, ‘biomass’ is a sophisticated term for anything found in nature but it has been used since the ancient people started making fire out of wood. With the new technologies appearing all the time, bioenergy can be related to two categories: traditional including wood, charcoal, animal waste combustion, and modern including biofuels from bagasse, bio-refineries, algae production for transport fuels, wood pellet systems, etc. About 70% of renewable energy used globally comes from biomass. Biomass has the potential to substitute fossil fuels in energy generation and replace some industrial products like plastics, lubricants, chemicals, fertilizers. Biomass can also be converted into biofuels for transportation purposes, such as biodiesel and cellulosic ethanol.
Organic materials used as biomass are called ‘feedstocks’. Biomass feedstocks are applied to create three types of energy, such as heat, electricity, and biofuels.
The most common biomass feedstocks are:
- crop wastes such as corn stover, wheat, and rice straw,
- grains and starch crops including sugar cane, sugar, beets, sweet potato,
- forest residues,
- purpose-grown grasses such as algae, miscanthus, switchgrass, willow,
- animal byproducts including fish oil and tallow,
- food waste,
- urban waste such as wastewater treatment sludge, urban wood waste, solid wastes, disaster debris, etc.
The most common technologies for extracting energy from biomass and its conversion:
Combustion including:
- direct combustion is the conversion of biomass to heat,
- fixed bed combustion is materials burning on a grate with air passage,
- co-firing is a cost-effective technology of burning biomass with other base fuel
- co-generation is used to capture waste heat from electricity generation;
- Gasification is a process of heating solid biomass to high temperatures (about 800-1000C) in a gasifier with limited oxygen;
- Pyrolysis works on high temperatures just like gasification only without the air;
- Anaerobic digestion is a biological biomass breakdown in conditions without oxygen.
The advantages of using bioenergy
Renewable energy source. This type of energy is always available, as the waste does not diminish, organic materials are constantly produced, and plants can be cultivated.
Waste reduction. Waste management has become an important global issue and generating energy from waste is the perfect solution for the problem.
Fossil fuels reduction. The possibility to convert biomass into fuels and electricity minimizes the negative impact on climate change.
Availability. Biomass is rather cheap and available in every household.
Biomass is different from other energy sources as it obtains resources from fields, forests, and other ecosystems influencing them positively and negatively at the same time. The greatest concern about using bioenergy is that the crops used for the energy occupy lots of land, which can be used for growing crops for food. It is important to produce and harvest biomass applying the management practices, which minimize negative impact and help follow sustainable development tasks locally.