We have used biomass energy or bioenergy – the energy from organic matter – for thousands of years, ever since people started burning wood to cook food or to keep warm. And today, wood is still our largest biomass energy resource. But many other sources of biomass can now be used, including plants, residues from
We have used biomass energy or bioenergy – the energy from organic matter – for thousands of years, ever since people started burning wood to cook food or to keep warm. And today, wood is still our largest biomass energy resource. But many other sources of biomass can now be used, including plants, residues from agriculture or forestry, and the organic component of municipal and industrial wastes. Even the fumes from landfills can be used as a biomass energy source.
The use of biomass energy has the potentialÂ to greatly reduce our greenhouse gas emissions. Biomass generates about theÂ same amount of carbon dioxide as fossil fuels, but every time a new plantÂ grows, carbon dioxide is actually removed from the atmosphere. The net emissionÂ of carbon dioxide will be zero as long as plants continue to be replenished forÂ biomass energy purposes. These energy crops, such as fast-growing trees andÂ grasses, are called biomass feedstocks.Â The use of biomass feedstockâ€™s can also help increase profits for theÂ agricultural industry.
Bosnia & Herzegovina has a remarkable potential utilizing biomass energy;Â being in favor of the fact that approximately 50% of BiH territory is coveredÂ with forests where one should not ignore and biomass in agriculture. UnusedÂ potentials of residual wood and wood waste, approximately 1 million m3/a, whichÂ could provide heat for 130,000 households or 300,000 inhabitants. In Bosnia andÂ Herzegovina currently has a very low proportion of biomass in its total energyÂ supply.
There are three majorÂ biomass energy technology applications:
Unlike other renewable energy sources,Â biomass can be converted directly into liquid fuels – biofuels – for ourÂ transportation needs (cars, trucks, buses, airplanes, and trains). The two mostÂ common types of biofuels are ethanolÂ and biodiesel.
Ethanol is an alcohol, the same found in beerÂ and wine. It is made by fermenting any biomass high in carbohydrates (starches,
sugars, or celluloses) through a process similar to brewing beer. Ethanol isÂ mostly used as a fuel additive to cut down a vehicle’s carbon monoxide andÂ other smog-causing emissions. But flexible-fuel vehicles, which run on mixturesÂ of gasoline and up to 85% ethanol, are now available.
Biodiesel is made by combining alcoholÂ (usually methanol) with vegetable oil, animal fat, or recycled cooking greases.Â It can be used as an additive to reduce vehicle emissions (typically 20%) or inÂ its pure form as a renewable alternative fuel for diesel engines.
Biopower, or biomass power, is the use ofÂ biomass to generate electricity. There are six major types of biopower systems:
direct-fired, co-firing, gasification, anaerobicÂ digestion, pyrolysis,Â and small, modular.
Most of the biopower plants in the world useÂ direct-fired systems. They burn bioenergy feedstocks directly to produce steam.
This steam is usually captured by a turbine, and a generator then converts itÂ into electricity. In some industries, the steam from the power plant is alsoÂ used for manufacturing processes or to heat buildings. These are known asÂ combined heat and power facilities. For instance, wood waste is often used toÂ produce both electricity and steam at paper mills.
Many coal-fired power plants can use co-firingÂ systems to significantly reduce emissions, especially sulfur dioxide emissions.
Co-firing involves using bioenergy feedstocks as a supplementary energy sourceÂ in high efficiency boilers.
Gasification systems use high temperaturesÂ and an oxygen-starved environment to convert biomass into a gas (a mixture of
hydrogen, carbon monoxide, and methane). The gas fuels what’s called a gasÂ turbine, which is very much like a jet engine, only it turns an electricÂ generator instead of propelling a jet.
The decay of biomass produces a gas – methaneÂ – that can be used as an energy source. In landfills, wells can be drilled toÂ release the methane from the decaying organic matter. Then pipes from each wellÂ carry the gas to a central point where it is filtered and cleaned before burning.Â Methane also can be produced from biomass through a process called anaerobicÂ digestion. Anaerobic digestion involves using bacteria to decompose organicÂ matter in the absence of oxygen.
Methane can be used as an energy source inÂ many ways. Most facilities burn it in a boiler to produce steam for electricityÂ generation or for industrial processes. Two new ways include the use ofÂ microturbines and fuel cells. Microturbines have outputs of 25 to 500Â kilowatts. About the size of a refrigerator, they can be used where there areÂ space limitations for power production. Methane can also be used as theÂ “fuel” in a fuel cell. Fuel cells work much like batteries but neverÂ need recharging, producing electricity as long as there’s fuel.
In addition to gas, liquid fuels can beÂ produced from biomass through a process called pyrolysis. Pyrolysis occurs whenÂ biomass is heated in the absence of oxygen. The biomass then turns into aÂ liquid called pyrolysis oil, which can be burned like petroleum to generateÂ electricity. A biopower system that uses pyrolysis oil is being commercialized.
Several biopower technologies can be used inÂ small, modular systems. A small, modular system generates electricity at aÂ capacity of 5 megawatts or less. This system is designed for use at the smallÂ town level or even at the consumer level. For example, some farmers use theÂ waste from their livestock to provide their farms with electricity. Not only doÂ these systems provide renewable energy, they also help farmers and ranchersÂ meet environmental regulations.
Whatever products we can make from fossilÂ fuels, we can make using biomass. These bioproducts, or biobased products, are
not only made from renewable sources, they also often require less energy toÂ produce than petroleum-based products.
Researchers have discovered that the processÂ for making biofuels – releasing the sugars that make up starch and cellulose in
plants – also can be used to make antifreeze, plastics, glues, artificialÂ sweeteners, and gel for toothpaste.
Other important building blocks forÂ bioproducts include carbon monoxide and hydrogen. When biomass is heated with a
small amount of oxygen present, these two gases are produced in abundance.Â Scientists call this mixture biosynthesis
gas. Biosynthesis gas can be used to make plastics and acids,Â which can be used in making photographic films, textiles, and syntheticÂ fabrics.
When biomass is heated in the absence ofÂ oxygen, it forms pyrolysis oil.Â A chemical called phenol can beÂ extracted from pyrolysis oil. Phenol is used to make wood adhesives, moldedÂ plastic, and foam insulation.