Biomass
Biomass is composed by animal or vegetable biological substances, which can become energy, if they are properly treated. Vegetables, thanks to the process called chlorophyllose photosynthesis, store the energy from the sun turning carbon dioxide into biological mass. Forests, woods, lawns are big sources of biomass. Some cities too can sometimes become good sources of biomass, thanks to the humid part of the citizens' rubbish, which can be combined with brashes and other material of trees and gardens. Biomass can be exploited in various ways:
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It can be burnt to produce thermal energy (in particular wood); |
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It can ferment in proper digesters, where some bacteria transform it into GAS (BIOGAS); |
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It can supply household appliances and other equipments able to improve the quality of life; |
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It can be used for the production of biofuel for explosion engines (biodiesel from rape oil, ethanol or ethyl alcohol from cereals and vegetables rich in sugar). |
In a lot of countries special cultivations are experimented to produce biomass to be transformed into biofuels and biogas. In Italy 250000 hectares are uncultivated, which could be used for the production of vegetable biomass and therefore renewable energy. Studies carried out by CNR in cooperation with ENEA and the University La Sapienza in Rome showed that biomass could be used to produce about 120000GWh of electrical energy per year, i.e. 40% of the electrical energy needs. Here is an example: from the fermentation of a ton of biomass you can obtain from 70 to 150m³ of biogas, which can produce till 190kWh of electrical energy, if treated in a cogeneration system.
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