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1. Biomass energy has the following 6 characteristics
①Renewability
Biomass energy is a renewable resource. Biomass energy can be regenerated through photosynthesis of plants, and is equivalent to wind energy and solar energy. It is a renewable energy source. It is rich in resources and can ensure the sustainable use of energy. Biomass energy is the only renewable energy that can be transported and stored.
②Low pollution
The biomass combustion process has little environmental pollution. The content of harmful substances in biomass is low, ash, nitrogen, sulfur and other harmful substances are far lower than mineral energy. The SOX and NOX generated in the combustion process are less, and the sulfur content of biomass is generally not higher than 0.2%; biomass is used as fuel At this time, since the carbon dioxide it needs for growth is equivalent to the amount of carbon dioxide it emits, its net carbon dioxide emissions to the atmosphere are close to zero, which can effectively reduce the greenhouse effect.
③Widely distributed
Biomass energy is universal and easy to take. Regardless of countries and regions, it is inexpensive, easy to obtain, and simple to process. In areas lacking coal, biomass energy can be fully utilized.
④The total amount of biomass fuel is very abundant
Biomass energy reserves are large and renewable. As long as there is sunlight, photosynthesis will not stop. Biomass energy is the fourth largest energy source in the world, second only to coal, oil and natural gas. According to estimates by biologists, the earth’s land produces 100 to 125 billion tons of biomass annually, and the ocean produces 50 billion tons of biomass annually. The annual production of biomass energy far exceeds the world's total energy demand, which is equivalent to 10 times the current world's total energy consumption. The biomass resources that can be developed into energy in China will reach 300 million tons by 2010. With the development of agriculture and forestry, especially the promotion of charcoal forests, biomass resources will continue to increase.
⑤ Biomass has high volatility and high carbon activity, which makes it easy to catch fire. There is little ash and slag after burning and it is not easy to stick.
⑥ Biomass has low energy density, large volume, and difficult transportation.
2. Several ways of utilization and conversion of biomass energy
The utilization of biomass energy mainly includes three ways: direct combustion (thermal energy-light energy), thermochemical conversion (thermal energy-chemical energy) and biochemical (thermal energy-chemical energy) conversion.
The direct combustion of biomass will continue to be the main method of biomass energy utilization in China for a long time to come. At present, traditional wood-burning stoves with a thermal efficiency of only about 10% are renovated, and wood-saving stoves with an efficiency of 20%-30% are promoted. The simple technology and easy promotion of wood-saving stoves are energy-saving measures with obvious benefits, and they are listed as new rural areas by the country. One of the key tasks of energy construction.
The thermochemical conversion of biomass refers to the technology of vaporization, carbonization, pyrolysis and catalytic liquefaction of biomass under certain temperature and conditions to produce gaseous fuels, liquid fuels and chemical substances.
Biochemical conversion of biomass includes biomass-biogas conversion and biomass-ethanol conversion. Biogas conversion is the production of a gas through microbial fermentation of organic substances in an anaerobic environment. This is a combustible mixed gas with methane as the main component, which is commonly referred to as biogas. Ethanol conversion uses raw materials such as sugar, starch and cellulose to produce ethanol gas through fermentation.