Biomass energy

Biomass energy is the energy form of solar energy stored in biomass in the form of chemical energy, ie biomass-based energy. It is directly or indirectly derived from the photosynthesis of green plants and can be converted into conventional solid, liquid, and gaseous fuels. It is inexhaustible and inexhaustible. It is a renewable energy source, and it is also the only renewable energy source. Carbon source.

Biomass

Biomass refers to various organisms that are produced through photosynthesis using the atmosphere, water, and land. That is, all living organic substances that can grow are commonly referred to as biomass. It includes plants, animals and microorganisms. Generalized concept: Biomass includes all plants, microbes, and animals that are plants, microbes, and their waste. Representative biomasses such as crops, crop residues, wood, wood waste, and animal waste. The concept of narrow sense: Biomass mainly refers to livestock and poultry in addition to grain and fruits except for grain and fruits in the agricultural and forestry production process. Lignocellulosic materials (such as lignin), waste from agricultural product processing, agricultural and forestry waste, and animal husbandry Feces and waste materials. Features: Reproducibility. Low pollution. Widely distributed.

Biomass Energy Overview

Biomass refers to all kinds of organisms formed through photosynthesis, including all plants and animals and microorganisms. The so-called biomass energy is the energy form of solar energy stored in biomass in the form of chemical energy, that is, biomass-based energy. It is directly or indirectly derived from the photosynthesis of green plants and can be converted into conventional solid, liquid, and gaseous fuels. It is inexhaustible and inexhaustible. It is a renewable energy source, and it is also the only renewable energy source. Carbon source. The original energy of biomass energy comes from the sun, so in a broad sense, biomass energy is a manifestation of solar energy. At present, many countries are actively researching and developing the use of biomass energy. Biomass energy is contained in plants, animals, and microorganisms that can grow organic matter. It is converted from solar energy. All energy substances derived from plants and animals other than fossil fuels in organic matter belong to biomass energy and usually include wood, forest waste, agricultural waste, aquatic plants, oil plants, urban and industrial organic waste, animal excrement, etc. . Biomass resources on the earth are more abundant and it is a harmless energy source. The Earth produces 173 billion tons of photosynthesis per year, which is equivalent to 10-20 times of the world's total energy consumption. However, the current utilization rate is less than 3%.

Biomass energy classification

According to the different sources, biomass suitable for energy use can be divided into five categories: forestry resources, agricultural resources, domestic sewage and industrial organic wastewater, municipal solid waste, and animal manure.

Forestry resources

Forest biomass resources refer to the biomass energy provided by the forest growth and forestry production processes, including fuel forest, scattered timber in the forest tending and thinning operations, residual branches, leaves and sawdust, etc.; Branches, sawdust, sawdust, shoots, slats, and truncations; waste from forestry by-products such as shells and kernels.

Agricultural resources

Agricultural biomass energy resources refer to agricultural crops (including energy crops); wastes in agricultural production processes, such as crop stalks (corn stalks, sorghum stalks, wheat straw, straw, bean stalks, and cotton stalks that remain in farmland when crops are harvested. Etc.); waste from agricultural processing, such as rice husks left over from agricultural production. Energy plants generally refer to various types of plants that are used to provide energy, and generally include herbaceous energy crops, oil crops, and the production of hydrocarbon plants and aquatic plants.

Domestic sewage and industrial organic wastewater

Domestic sewage is mainly composed of various drainages in the life, business and service industries of urban residents, such as cooling water, bath drainage, toilet drainage, laundry drainage, kitchen drainage, and fecal sewage. Industrial organic wastewater is mainly wastewater discharged from the production process of alcohol, brewing, sugar, food, pharmaceuticals, papermaking and slaughtering industries, all of which are rich in organic matter.

Municipal solid waste

Urban solid waste is mainly composed of solid waste such as urban residents' living garbage, commercial and service industry garbage, and a small amount of construction industry garbage. Its composition is relatively complex and affected by the average living standards of local residents, energy consumption structure, urban construction, natural conditions, traditional habits, and seasonal changes.

Livestock manure

Livestock and poultry manure is the general term for livestock and poultry excrement. It is a form of transformation of other forms of biomass (mainly foodstuffs, crop stalks, pastures, etc.), including excrement of livestock and poultry, urine, and a mixture thereof.

Biogas

Biogas is a combustible gas that is converted by biomass energy and can usually be used by farmers for cooking and lighting.

Biomass energy characteristics

1) Renewability

Biomass energy is a renewable resource. Biomass energy can be regenerated by photosynthesis through plants. It is equal to renewable energy with wind energy and solar energy. It is rich in resources and can guarantee the sustainable use of energy;

2) Low pollution

The content of biomass*, low nitrogen content, and less SOX and NOX generated during combustion; when biomass is used as fuel, the carbon dioxide required for its growth is equivalent to the amount of carbon dioxide it emits, and thus the net carbon dioxide of the atmosphere Emissions are approximately zero, which can effectively reduce the greenhouse effect;

3) Widely distributed

Areas lacking coal can make full use of biomass energy;

4) The total amount of biomass fuel is very rich

Biomass energy is the fourth largest energy source in the world, second only to coal, oil and natural gas. According to biologists' estimates, the Earth's land produces 1,000 to 125 billion tons of biomass per year; oceans produce 50 billion tons of biomass each year. The annual production of biomass energy far exceeds the total energy demand in the world, which is equivalent to 10 times the current world total energy consumption. The biomass resources that China can develop into energy resources can reach 300 million tons by 2010. With the development of agroforestry, especially the promotion of charcoal forests, there will be more and more biomass resources.

Applications: Biogas, compressed solid fuel, gasification gas production, gasification power generation, production of fuel alcohol, thermal cracking production of biodiesel, etc.

The use of biomass energy

Biomass energy has always been an important source of energy for human survival. It is second only to coal, oil and natural gas and ranks fourth in the world's total energy consumption, and occupies an important position in the entire energy system. Relevant experts estimate that biomass energy is likely to become an integral part of the future sustainable energy system. By the middle of the next century, biomass-based alternative fuels produced using new technologies will account for more than 40% of the total global energy consumption.

At present, human beings use biomass energy, including crop straws and fuel wood that are used directly as fuel; indirect fuels include agricultural and forestry waste, animal manure, garbage, and algae, etc., which generate biogas through the action of microorganisms, or Pyrolysis produces liquid and gaseous fuels and can also produce biochar. Biomass energy is the world's most extensive renewable energy source. It is estimated that the annual total amount of biomass generated by photosynthesis on the earth alone amounts to 144 to 180 billion tons (dry weight), which is equivalent to approximately 3 to 8 times the world's total energy consumption in the early 1990s. However, it has not yet been rationally used by people. Most of them are directly used as fuel wood, which has low efficiency and affects the ecological environment. The use of modern biomass energy is through the anaerobic fermentation of biomass to produce methane, the use of pyrolysis to produce fuel gas, bio-oil and bio-char, the use of biomass to make ethanol and methanol fuel, and the use of bio-engineering technologies to cultivate energy plants. Development of energy farms.