Biomass is organic material which has stored sunlight in the form of chemical energy. Biomass fuels include wood, wood waste, straw, manure, sugar cane, and many other byproducts from a variety of agricultural processes.
Biomass is a renewable energy source because the energy it contains comes from the sun. Through the process of photosynthesis, chlorophyll in plants captures the sun’s energy by converting carbon dioxide from the air and water from the ground into carbohydrates, complex compounds composed of carbon, hydrogen, and oxygen. When these carbohydrates are burned, they turn back into carbon dioxide and water and release the sun’s energy they contain.
The definition of term biomass is: Biomass typically refers to organic material, which can be recycled. Biomass includes crops, crop wastes, trees, wood waste and animal waste. Some examples of biomass include wood chips, corn, corn stalks, soybeans, switchgrass, straw, animal waste and food-processing by-products. Other example of biomass are solid and liquid agricultural waste, municipal waste, industrial waste. Fast-growing trees and grasses are great energy sources of biomass as well.
Wood pellets are a type of wood fuel, generally made from compacted sawdust. They are usually produced as a byproduct of sawmilling and other wood transformation activities. The pellets are extremely dense and can be produced with a low humidity content (below 10%) that allows them to be burned with a very high combustion efficiency.
The energy content of wood pellets is approximately 4.7-4.9 MWh/tonne (~7450 BTU/lb).
High-efficiency wood pellet stoves and boilers have been developed in recent years, offering combustion efficiencies of over 90%
Biomass briquettes are made from agricultural waste and are a replacement for fossil fuels such as oil or coal, and can be used to heat boilers in manufacturing plants, and also have applications in developing countries. Biomass briquettes are a renewable source of energy and avoid adding fossil carbon to the atmosphere. Moisture content of a briquette can be as low as 4%, whereas green firewood may be as high as 65%.
Oil plants and biofuels
Oil plants are soybeans and sunflowers produce oil, which can be used to make fuels.
Biofuel (also called agrofuel) is a biorganic fuel. This is a scientific name for any plant or animal substance that can burn (combustible organism organic) of two types , plant and animal). Biofuel is an alternative considered to replace petroleum gas (gasoline) or petrol. Bioethanol, Biomethane and biodiesel are biofuels.
Biofuels can be used as transportation fuels liquids and non-transportation for combined heat and power generation.
Industrial residues are solid (as paper, fibers, textile, pulp, etc.) and liquid industrial residues (which could be used for production of biodiesel, ethanol, etc.).
Municipal solid waste (MSW) is a waste that includes predominantly household waste (domestic waste) with sometimes the addition of commercial wastes collected by a municipality within a given area. The term residual waste relates to waste left from household sources containing materials that have not been separated out or sent for reprocessing.
Waste management is sometimes carried out directly by a department of local government, and sometimes by a private company under contract
Technologies that we used to produce energy from biomass are 2 main categories: primary energy conversion technologies and secondary energy conversion technologies.
Primary energy conversion technologies
Combustion – direct combustion of biomass is the most common way of converting biomass to energy – both heat and electricity. Compared to the gasification and pyrolisys it is the simplest and most developed.
Gasification – as direct compustion, gasification is a high-temperature (1200-1400 Degree Celsius)thermochemical conversion process but the process is used for production of gas, instead of heat.
Pyrolysis – thermal decomposition occuring in the absense of oxygen. We use pyrolysis to produce a liquid fuel, bio-oil or pyrolysis oil.
Secondary energy conversion technologies
Steam engine are used in industrial environments but are still expensive. Steam turbines are used in large scale power generation and cogeneration plants.
Biomass and environment
Using biomass as an energy source means that the carbon dioxide (that was absorbed while the plant was growing) is released back into the air when the biomass is burned. This process could be called carbon neutral.
Forest play very important role at local and global level. It is provide energy for industrial, commercial and domestic use. Human inpact however often damage forest environments – deforestration for timber and for the conversion of land for agricultural purpose. Forest are damaged by pollution including acid rain and fires or storms.
Growing bioenergy crops can play a role in the protection of groundwater.
To protect and keep the soil clean is very important for the plants. All plants depend on it as a reserve of nutrients.