The principle of biomass power generation in agriculture and forestry, the current situation of biom

In China, the comprehensive utilization of agricultural and forestry biomass is mainly concentrated in power generation and liquid fuels, and industries such as biomass pellet fuels and bio-natural gas have started and shown a good momentum of development [1]. The rock power generation technology of China's Bureau of Agriculture and Forestry Biology has been basically mature, but the development is relatively slow, and the installed capacity of agriculture and forestry biomass power generation accounts for about the whole country. Bio-liquid fuels include fuel ethanol, biodiesel, and biomass hot stools [2], and biodiesel is in the early stage of industrial development. Biomass pellet fuel is mainly used in urban heating and industrial heating, which is still in the early stage of large-scale development. Bio-natural gas is mainly used for the production of biogas.

Biomass power generation is a new form of business, and the focus of biomass power generation is the focus of China's wide and tolerant rural areas. However, due to the fact that our current agriculture is mainly contracted by households, the straw is scattered, and the transportation cost is high, so it is difficult to achieve large-scale.

Biopower generation: refers to the electricity generated by the use of a special synthesis of organisms, and humans can collect and convert the electrical energy emitted by organisms into a new bioenergy.

Biomass is the process of photosynthesis in plants.

The organic matter generated, including plant and animal excrement, garbage and organic wastewater, is biomass energy.

is the only renewable energy that can be stored and transported.

From a chemical point of view, the composition of biomass is C-H compound, which is the same as conventional mineral energy such as petroleum and coal, (coal and spring resistant petroleum are biomass converted from long-term conversion), so its characteristics and utilization methods are very similar to fossil fuels, and can make full use of the conventional energy technology that has been developed to develop and utilize biomass energy, which is also one of the advantages of Kaiyunsen Glide Hair using biomass energy.

The new biomass power generation technology is generally used in the power generation system based on burning straw and other agricultural and forestry crops.

Its technical feature is the large area of the boiler furnace because of the low calorific value of the straw. Using conventional steam turbines and generators to generate electricity, the technology is mature and simple.

It is worrying that a lot of straw that should have been used for silage has been burned, reducing the amount of feed**.

In addition, straw is an important raw material for papermaking, and when it is burned, it is necessary to obtain raw materials from such as cutting down trees.

Secondly, power generation boilers must work continuously 24 hours a day, and a huge amount of fuel needs to be burned every year. However, straw harvesting has a strict harvest period, so the uniformity of these straw fuels has become a big problem that is difficult to solve. Otherwise, power generation cannot be continuous.

For example, crops are only harvested 2-3 times a year. Salix in desert areas has the special effect of windbreak and sand fixation, but it must be cut down every 3 years or so to keep it vigorous. Therefore avoid looking at the large planting area, but in fact only a third can be cut in turn.

If a large number of crops are planted, there will inevitably be a contradiction between "competing for land with grain" and "competing for land with vegetables", and the consequences will be serious.

If a large amount of straw is purchased at one time, the required warehouse area is very large, the investment is huge, and it is easy to catch fire for long-term stacking.

If a large number of piles are stacked in the open air, they will be affected by the rainstorm season after getting wet.

Therefore, it is important not to build a large number of biomass power plants that burn straw.

Biomass direct combustion power generation refers to the direct combustion of biomass raw materials into specific boilers suitable for biomass combustion to produce steam and drive steam turbines and generators to generate electricity. There are many types of biomass boilers that have been developed and applied. Such as wood boilers, bagasse boilers, rice husk boilers, straw boilers, etc.

It is suitable for areas where biomass resources are concentrated, such as near millet processing factories and wood processing plants. Because as long as the factory is in normal production, chaff, sawdust and firewood can provide a continuous supply of electricity.

The biomass combustion methods in biomass direct combustion power generation technology include fixed bed combustion or fluidized bed combustion. Fixed-bed combustion has low requirements for the pretreatment of biomass raw materials, and the biomass can be put into the grate furnace for combustion after simple treatment or even no treatment. Fluidized bed combustion requires the pre-crushing of large biomass feedstocks to a particle size that can be easily fluidized.

Its combustion efficiency and strength are higher than those of fixed beds.

This technology is rarely used in our country because it requires the concentration of biomass resources and the quantity is huge. If the biomass is collected or transported on a large scale. It will increase the cost of raw materials.

Therefore, this technology is more suitable for waste treatment on modern large farms or large processing plants. There are two main gasification methods: biochemical method and thermochemical method.

The biochemical production of combustible gas mainly refers to the decomposition of raw materials (organic waste) into several large molecules such as starch and cellulose, and then directly converting them into fatty acids (acetic acid, etc.), and then methanizing bacteria begin to work on anaerobic digestion to produce biogas.

Thermochemical method is to heat the temperature to more than 600, in the absence of oxygen to the organic matter of the "dry distillation" of this kind of pyrolysis products and coal pyrolysis is very similar, the solid product is coke analogue, the gas product is the "furnace gas" analogue, a biogas from livestock and poultry manure or industrial wastewater containing organic matter, through anaerobic fermentation to produce CH4 and CO2 as the main body of mixed gas. The amount of CH4 content determines the calorific value of biogas, which has an impact on the power generation efficiency of biogas.

Biogas power generation is a biogas utilization technology that appears with the continuous development of comprehensive utilization of biogas, which uses anaerobic fermentation technology to ferment slaughterhouse or other organic wastewater and livestock and poultry manure from breeding farms to produce biogas, supply internal combustion engine or gas turbine, drive generator to generate electricity, and also supply steam boiler to generate steam and drive steam turbine to generate electricity. Biogas belongs to biomass energy, which is a clean energy that can be utilized. It has a high calorific value, good anti-explosion performance, clean combustion, and can be used for heating, cooking, lighting, power generation, etc.

Biogas power generation technology is mainly used in livestock plant biogas, industrial wastewater treatment biogas and landfill biogas. Promoting the application of biogas power generation is conducive to protecting the ecological environment and reducing greenhouse gas emissions; It is an important guarantee for increasing farmers' income; It can improve the production and living conditions of farmers and bring huge social, ecological and economic benefits.