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1 What is biomass 1.1 Definition and classification It refers to all materials in organic matter that can be regenerated from animals and plants except fossil fuels. It is a collection of living tissues and their derivatives and substances related to biological transformation. It is an organic matter produced by photosynthesis. Biomass is the carrier of biomass energy and is the general term for all living and regenerable organic matter, including animals, plants and microorganisms. There are many types of biomass that can provide biomass fuel for humans, which can be roughly divided into 7 categories: a) Municipal waste: industrial, domestic and commercial waste, 1 billion tons are discharged globally every year; b) Organic wastewater: industrial wastewater and domestic sewage, 450 billion tons are discharged globally every year; c) Feces: poultry, livestock manure, etc., more than tens of billions of tons are discharged globally every year; d) Forestry biomass: Firewood, fallen leaves, bark, roots and forestry processing waste, etc.; e) Agricultural waste: straw, fruit shells, fruit cores, corn cobs, etc.; f) Aquatic plants: algae, duckweed, water hyacinth, water hyacinth, etc.; g) Energy plants: trees, shrubs and herbs that grow rapidly and have short rotation periods. 1.2 Characteristics a) Moisture changes greatly. Generally between 5 and 60%. b) Low calorific value, low density, high carbon activity, and the biomass combustion process has the characteristics of CO2 emissions. c) High volatile content d) Low sulfur content (S content is 0.1% ~ 1.5%, wood is generally less than 0.05%) e) Medium nitrogen content (N content is 0.5% ~ 3%) f) Low ash content (0.1% ~ 3%) g) High nutritional elements 2 What is biomass energy 2.1 Definition: Biomass energy is the energy contained in biomass. It refers to the energy that is converted into chemical energy directly or indirectly through the photosynthesis of green plants and then fixed and stored in living organisms. Its chemical reaction formula: 6CO2 6H2O →6O2 C6H12O6 1840kJ/mol It is a unique renewable carbon source that can be converted into conventional solid, liquid and gaseous fuels. The amount of energy contained in biomass is closely related to the following factors: Varieties, growth cycles, breeding and seeding methods, harvesting methods, disease and disaster resistance, sunshine time and intensity, environmental temperature and humidity, rainfall, soil conditions, etc. have great potential in biomass energy. There are about 250,000 species of organisms in the world. It is estimated that the carbon fixed by plant photosynthesis every year on the earth reaches 2x1011t, and the energy content reaches 3x1021J. Therefore, the solar energy stored in the branches, stems and leaves of plants through photosynthesis every year is equivalent to 10 times the annual energy consumption in the world. Biomass is found all over the world, and its reserves are huge. The annual production of plants on the earth alone is equivalent to 20 times the mineral energy currently consumed by humans, or equivalent to 160 times the food energy of the world's current population. Although different * * Biomass production per unit area varies greatly, but every * * All have some form of biomass. Biomass energy has always been an important energy source for human survival. It ranks fourth in the world's total energy consumption after coal, oil and natural gas. It occupies an important position in the entire energy system. In the future, biomass energy will become one of the pillar energy sources. 2.2 Characteristics Compared with fossil fuels Compared with fossil fuel energy, biomass energy has unique advantages: a) Renewability Biomass is a renewable resource. Biomass energy can be regenerated through photosynthesis of plants. It is a renewable energy source equivalent to wind energy and solar energy. It is rich in resources and can ensure the sustainable use of energy. b) Low-pollution biomass has low sulfur and nitrogen contents and less SOX and NOX during combustion. ； When biomass is used as fuel, since the carbon dioxide it requires during growth is equivalent to the amount of carbon dioxide it emits, the net carbon dioxide emissions to the atmosphere are close to zero, which can effectively reduce the greenhouse effect. ； c) Biomass energy can be fully utilized in widely distributed areas lacking coal. d) The total amount of biomass fuel is very abundant. Biomass energy is the fourth largest energy source in the world. According to estimates by biologists, the earth's land produces 100 to 125 billion tons of dry biomass every year; the ocean produces 50 billion tons of dry biomass every year. The annual production of biomass energy far exceeds the world's total energy demand, equivalent to 10 times the current world's total energy consumption. my country's biomass resources that can be developed as energy will reach 300 million tons by 2010. With the development of agriculture and forestry, especially the promotion of firewood forests, there will be more and more biomass resources.