Biomass

Energy Oil and Energy 








Biomass is an industry term for getting energy by burning wood, and other organic matter. Burning biomass releases carbon emissions, but has been classed as a renewable energy source in the EU and UN legal frameworks, because plant stocks can be replaced with new growth. It has become popular among coal power stations, which switch from coal to biomass in order to convert to renewable energy generation without wasting existing generating plant and infrastructure.

Biomass
Biomass most often refers to plants or plant-based materials that are not used for food or feed, and are specifically called lignocellulosic biomass. As an energy source, biomass can either be used directly via combustion to produce heat, or indirectly after converting it to various forms of biofuel. Conversion of biomass to biofuel can be achieved by different methods which are broadly classified into: thermal, chemical, and biochemical. Some chemical constituents of plant biomass include lignins, cellulose, and hemicellulose.


A biomass-fired power plant produces electricity and heat by burning biomass in a boiler. The most common types of boilers are hot water boilers and steam boilers. Wood chips, residues and other types of biomass are used in the boilers, in the same way as coal, natural gas and oil. Fuel is stored in a bunker for further transport to the boiler. In the boiler, water is heated to high temperature under pressure. Steam from the boiler powers the turbine, which is connected to the generator.

On combustion, the carbon from biomass is released into the atmosphere as carbon dioxide (CO2). After a period of time ranging from a few months to decades, the CO2 produced from combustion is absorbed from the atmosphere by plants or trees. However, the carbon storage capacity of forests may be reduced overall if destructive forestry techniques are employed.


All biomass crops sequester carbon. For example, soil organic carbon has been observed to be greater below switchgrass crops than under cultivated cropland, especially at depths below 30 cm (12 in). For Miscanthus x giganteus, McCalmont et al. found accumulation rates ranging from 0.42 to 3.8 tonnes per hectare per year,  with a mean accumulation rate of 1.84 tonne (0.74 tonnes per acre per year), or 20% of total harvested carbon per year. The grass sequesters carbon in its continually increasing root biomass, together with carbon input from fallen leaves.


Typically, perennial crops sequester more carbon than annual crops because the root buildup is allowed to continue undisturbed over many years. Also, perennial crops avoid the yearly tillage procedures (plowing, digging) associated with growing annual crops. Tilling induces soil aeration, which accelerates the soil carbon decomposition rate, by stimulating soil microbe populations. Also, tilling makes it easier for the oxygen (O) atoms in the atmosphere to attach to carbon (C) atoms in the soil, producing CO2. More details