FreeWord – Biomass, the carbon-neutral energy source
Hello folks! Most of us know a very little bit about biomass. Ever since the first human discovered how to make a fire, we have been utilizing biomass energy in some way on a daily basis. Whether we burn wood for heat or use it for cooking, we are using a form of biomass energy. Biomass is composed of organic material obtained mainly from plants and animals. Properly produced biomass energy is carbon neutral electricity generated from renewable organic waste that would otherwise be dumped in landfills, openly burned, or left as fodder for forest fires.
Waste: human waste, animal waste, rotting garbage
Plants: sugarcane, algae, straw, corn, sugarcane, wheat
Wood: dead trees, stumps, stray branches, chips, clippings
Garbage: municipal solid waste, waste from manufacturing plants
Biomass and the environment
Unlike fossil fuels that release carbon back into the atmosphere, most biofuels are completely eco-friendly. However, the cultivation and production of biomass must be carried out in a controlled, sustainable manner in order to secure zero emissions. An important fact to note is that not all biofuels have zero emissions. The same goes for biomass as for any other energy source, we should favor locally sourced fuel sources like forest residues to reduce emissions from transportation. There are two types of biofuels created from biomass, depending on what type of biomass has been used.
First generation biofuels – Using biomass sources such as sugarcane residues or corn starch, first-generation biofuels are created as a result of the fermentation of the sugar in these residues. The resulting fuels are alcohol based and can be used to make electricity directly or can be added to gasoline. Examples: biodiesel and bioethanol.
Second generation biofuels – When biomass mainly contains agricultural residues and municipal waste, the creation of a second-generation biofuel process is needed and it’s more complicated. Lignocellulosic biomass components are common in the generation of the energy of this type of biomass. The sugar monomers of the polymers in the plant dry matter are used for (re-) generation of fuels such as bioethanol.
Although the second generation of biofuels is largely preferred, it is still challenging to create. We have yet to figure out the workarounds for the unstable technology, in order to counter the structural rigidity or the chemical inertness of the lignocellulosic biomass. However, there is constant research and development to find proper solutions.
Biomass into energy
Biomass energy is the result of burning or converting biomass. Energy production depends equally on the transformation process and the exact type of biomass used. The plant biomass absorbs CO2 (carbon dioxide) from the atmosphere during its growth, and it returns it during combustion. Therefore, the CO2 balance of the right executed processes is zero. Any material that has an organic matrix, like municipal waste, can be defined as biomass. For this reason, we prefer to talk about “plant biomass”, limiting its origin to the plant world. The plant’s biomass energy is transformed by three processes, divided into three major groups: thermo-chemical, biological and physical.
Direct Combustion (in excess of air) – The most common way of converting organic matter into energy. Burning wood, waste and other plant matter releases stored chemical energy in the form of heat and converting it to electricity.
Pyrolysis (Indirect combustion -without the presence of oxygen) – represents the thermochemical decomposition of biomass. Through this process, biomass is converted into bio-coal and other useful materials. Temperatures of 200-300 degrees Celsius are precisely the ones needed for pyrolysis. This method is also used to turn plastics into reusable oils.
Gasification (partial combustion – the presence of a small amount of oxygen) – Heating biomass at extremely high temperatures (over 700 degrees Celsius) without lighting it on fire, while steam and oxygen are released during the reaction. The final results are carbon monoxide, carbon dioxide, and hydrogen. The compound gas made up of the three is called syngas, which is a biofuel that is extremely flammable, and its combustion is a great source of energy.
Biogas (anaerobic digestion) – forms of paper, food scraps, and yard waste decompose in landfills and can be produced by processing sewage and animal manure in special vessels called digesters. Methane can be captured by a machine called Microturbine and converted into electricity. However, most are converted to ethanol and biodiesel.
Ethanol (Fermentation) – fuel that is produced through contemporary biological processes – that is, plant or algae material or animal waste. Ethanol is made from crops such as corn and sugar cane that are fermented to produce fuel ethanol for use in vehicles.
Bio-diesel (Trans-esterification) – produced from vegetable oils and animal fats, and can be used in vehicles and as heating oil.
Anaerobic digestion (or biodigestion) – a biological process that occurs when organic matter is decomposed by bacteria in the absence of oxygen. As the bacteria decompose organic matter, biogas is released and captured.
Future of biomass
The supply of larger volumes with biomass is currently difficult to secure, but the amount of fuel that biomass products could create is phenomenal. This would require the developed world to heavily invest resources into the production of biomass energy. It is estimated that biomass would be able to produce an equivalent amount of fuel to what the OPEC nations produce in crude oil on a daily basis.
Algae may unlock the future potential of biomass. Its success depends mostly on catching up with the right varieties for cultivation. When compared to other fuels that are made from more traditional crops, algae can be harvested much faster since it produces 3-4 crops per year. Fermentation of algae has been proven to produce fuels such as butanol, methane, hydrogen, and biofuels intended for vehicular use. Global use would lead to carbon dioxide reduction. All hail the algae!
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