The main energy source of traditional agriculture

1. Popularization and application status of rural household biogas

At present, the popularization and application scale of biogas digesters in China ranks first in the world, and the country plans to reach 26 million by 20 10. In this way, the number of ponds will account for 20% of farmers suitable for biogas development in China. However, the management pressure brought by such a huge pool construction and amazing development speed can be imagined. Technical cadres should not only be responsible for the planning, setting-out and construction of new ponds, but also be responsible for the troubleshooting of various faults in the management and use of old ponds and the guidance and training of comprehensive utilization technology.

2. The significance of promoting biogas to users.

(1) Biogas can not only solve rural energy problems, but also increase organic fertilizer resources, improve quality and fertilizer efficiency, thus increasing crop yield and improving soil; (2) The use of biogas can save a lot of organic matter such as straw and hay, which can be used to produce livestock feed and used as raw materials for papermaking and handicrafts; (3) Setting biogas can reduce the phenomenon of cutting trees and shoveling turf, protect vegetation and make the agricultural production system develop in a virtuous circle step by step; (4) Setting biogas is beneficial to purify the environment and reduce the occurrence of diseases. This is because in the process of biogas digester fermentation, a large number of bacteria in human and animal feces die, which improves the environmental sanitation conditions; (5) Cooking and lighting with biogas can not only save family economic expenses, but also save housewives' labor time and reduce labor intensity; (6) Using biogas manure to improve the quality of agricultural products, increase economic income, reduce agricultural pollution, and lay a foundation for the production of pollution-free agricultural products. The commonly used ecosystem of material recycling mainly includes the trinity combination of planting, aquaculture and biogas engineering, the trinity combination of aquatic products, fisheries and planting, and the trinity combination of aquatic products, fisheries and forestry. Among them, the ecological engineering combining material circulation with planting, breeding and biogas engineering is the most common and has the best effect.

Biogas has become a link between farming and planting, energy for daily use and fertilizer for production. It is the best way to realize the transformation of fuel, fertilizer and feed, and plays a special role in the recycling of energy and materials of agricultural wastes. Developing rural biogas and building ecological homes can not only provide high-grade clean energy for farmers, but also increase farmers' income through the extension of ecological chain. At the same time, it can protect and restore forest vegetation, reduce environmental pollution and promote the improvement of ecological environment.

I. Economic impact

With the development of society, people's living standards have been continuously improved, and their spiritual and material lives have also been significantly improved. In order to change the situation that cooking with firewood for three meals a day is smoky, difficult to enter the kitchen and difficult to control hygiene. The average household uses a briquette furnace to burn liquefied petroleum gas. Although coal and liquefied petroleum gas are very convenient and hygienic, they consume a lot of money. If a family of four only uses liquefied petroleum gas, one bottle a month is enough. Now a bottle of LPG is 80-90 yuan, and the net LPG is 900- 1200 yuan a year. A new 8 cubic meters high-efficiency biogas digester will be built, with an annual output of 380 cubic meters of biogas, which is fully needed for lighting, cooking and bathing all year round. A family of four can save more than 2,000 kilograms of coal and about 200 degrees of electricity a year, and can save various expenses of 1000 yuan a year. Biogas can be used not only for cooking and lighting, but also for agricultural production. Applying carbon dioxide gas fertilizer to vegetables in biogas lamp greenhouse can increase the yield of cucumber by 30%, celery by 25% and tomato by 20%. Using biogas to raise silkworms, the air in the silkworm room is fresh, clean and hygienic, and there is no dust. The cocoon output increased by 10%, and the economic benefit was very remarkable. Use biogas to dry grain, agricultural and sideline products, store grain with biogas to prevent insects, and preserve biogas fruits. It has the advantages of simple equipment, convenient operation, no smoke, low cost and good benefit. An 8 cubic meter biogas digester can provide biogas fertilizer for one year, which is equivalent to 50 kilograms of ammonium sulfate, 40 kilograms of calcium superphosphate and 15 kilograms of potassium chloride. The application of biogas fertilizer can improve the quality of all food crops, cash crops and fruit trees, and the yield increase effect is very significant, with the yield increase range generally ranging from 5% to 20%. Soaking seeds with biogas slurry can improve germination rate and seedling rate, improve seedling quality, and enhance disease resistance and stress resistance of seedlings, which has good economic benefits. When biogas slurry is used as feed additive for pigs, it can be released 20 ~ 30 days in advance, and the average cost per pig can be saved by about 40 yuan. Fish culture with biogas slurry can increase production by 10%. Mushroom cultivation with biogas residue can increase production and income by 20% ~ 30%. In a word, the combination of biogas fermentation system and agricultural leading industries will double the economic benefits. The "four-in-one" ecological greenhouse model in northern rural areas combines biogas digesters, pig houses, toilets and solar greenhouses into a biogas comprehensive utilization system, and each system increases economic income by 4000 ~ 8000 yuan per year. Large farmers and planters produce and operate more than 100 mu, and the benefits of increasing income and reducing expenditure are more significant. For example, no matter how the market changes, taking the road of comprehensive development and utilization of ecological four-in-one resources will realize that others will earn small profits on credit, others will earn big profits on credit, and others will earn big profits on credit, and I will make a fortune!

Second, the ecological effect.

The development and utilization of rural biogas can effectively alleviate the situation of rural energy shortage, protect and restore forest vegetation, and promote the improvement of ecological environment. A new efficient biogas digester with an area of 8 cubic meters can produce biogas a year, which is equivalent to the annual energy of 3 mu of firewood forest or the surface biological yield of 150 mu of arid grassland. Building a biogas digester is equivalent to building 3 mu of firewood forest, saving afforestation cost, 600 yuan.

Developing rural biogas is a strategic measure to solve rural energy shortage, reduce deforestation, protect forest vegetation, reduce soil erosion and restore and rebuild ecological environment.

Developing rural biogas can solve the problems of fuel and fertilizer and reduce the pollution of pesticides and fertilizers. The solution of fuel is conducive to restoring forest ecological balance and providing a suitable environment for natural enemies of pests; At the same time, after the organic matter is fermented by biogas, most parasitic pests and diseases are killed, reducing the source of pests and diseases, which will inevitably lead to the reduction of pesticide application. Forest restoration reduces soil erosion and improves soil fertility. In addition, a large number of high-quality biogas manure returned to the field provides a material basis for increasing soil nutrition and reducing chemical fertilizer application. It can be seen that the development of biogas in rural areas has comprehensive benefits for directly and indirectly reducing the environmental pollution caused by chemical fertilizers and pesticides.

Developing rural biogas can improve soil and increase soil organic matter. The content of humic acid in biogas manure is 10 ~ 20%, which has a direct effect on the formation of soil aggregate structure. Ammonia nitrogen and protein nitrogen in biogas manure make this organic fertilizer have the characteristics of slow-release and fertilizer efficiency; Organic components such as fiber in biogas manure provide the necessary foundation for loosening soil and improving soil organic matter content; A large number of active trace elements in biogas fertilizer are the factors to improve fertilizer utilization rate and enhance soil fertility. In the soil with long-term application of biogas fertilizer, the contents of organic matter, nitrogen, phosphorus, potassium and other nutrient elements increased obviously, soil enzyme activity increased, soil physical properties were improved to varying degrees, crop utilization and absorption of nutrients increased, soil fertility improved significantly, and agricultural production increased continuously.

Third, the health effect.

Human and animal manure is the main raw material for biogas fermentation, but from the health point of view, it is the source of infection of many diseases. At present, the sanitation in our countryside is really flattering. In summer, especially in rainy weather, yellow water is flowing, stinking, and mosquitoes and flies are flying around. These flies may sting on toilet feces for a while, or they may fly to the kitchen to eat. Can people live in such an environment? Using biogas digesters to treat human and animal manure can not only kill insects and sterilize, but also obtain high-quality energy and fertilizer. Build a trinity system of garden toilet, piggery and biogas digester, so that the feces of toilet and piggery can automatically flow into the pool. After biogas fermentation, most parasitic eggs can be killed: Schistosoma eggs are killed in 7-22 days under the condition of biogas fermentation at room temperature; The mortality of hookworm eggs was 75% after 50 days, and all of them died after 93 days. After 90 days, the mortality rate of ascaris eggs was 75%; The survival time of typhoid Bacillus is only 30 days; After 30 hours, Shigella flexneri was negative, but it could survive 17 days in general fecal fluid. After three years' investigation on soil samples of vegetable fields of farmers who promoted biogas digesters and did not build biogas digesters, it was found that the pollution of hookworm eggs decreased by 60-84.6%, the pollution of ascaris eggs decreased by 50-76%, and the pollution degree was greatly reduced. The former contains 65438 0.65 hookworm eggs and 438 0 ascaris eggs per 100 grams of soil, while the latter is as high as 6.59 eggs.

Developing biogas can reduce the breeding of mosquitoes and flies. Through the investigation of biogas and biogas-free farmers, the results show that the fly density of chicken farmers is lower than that of biogas-free farmers by 63.57%; The density of flies in pig farms is 93% lower than that in pig farms.

The development of biogas can reduce the indoor air pollution caused by toxic gases and carcinogens such as carbon monoxide, sulfur dioxide and sulfur trioxide produced by coal burning, and completely change the "dirty, chaotic and poor" sanitary appearance in rural areas. Methane accounts for 60 ~ 70% in biogas, which produces heat energy and carbon dioxide when burned, and there are almost no harmful substances.

The development of biogas replacing firewood and coal has eliminated a large amount of coal ash produced by coal burning, and reduced garbage disposal and environmental pollution. According to the comparative investigation of villages with biogas as energy source and coal as energy source, the indoor CO concentration of the former is 3.8 times lower than that of the latter, the CO2 concentration is 65,438 0.4 times lower, the SO2 concentration is 3.8 times lower and the floating dust concentration is 4.4 times lower.

Developing biogas can effectively protect water sources, reduce pollution and improve the quality of water environment. According to the monitoring of drinking water sources in villages with and without biogas, the qualified rates of total bacteria, coliform, ammonia nitrogen and chloride increased by 465, 438+0.86 ~ 78.26%, 50.0%, 55.02% and 56.75438+0% respectively.

Fourth, social effects.

After the establishment of the eco-agricultural system in the park with high-efficiency biogas as the link, it effectively solved the transfer and digestion of surplus labor force, stimulated farmers' enthusiasm in learning and applying science, and turned practical technology into practical productivity, enhanced farmers' scientific and technological awareness, improved farmers' scientific and technological quality, made a high-level use of the limited park, and made contributions to the prosperity of urban and rural markets.

Developing rural biogas and building ecological homes can free women from heavy kitchen work, free up time for yard production and increase economic income. It is conducive to improving the quality of life and health of rural population and reducing the incidence of common diseases. The investigation shows that the intestinal infectious diseases of villagers who use biogas digesters to manage feces are reduced by 62.5 ~ 77.8% compared with those who do not use biogas digesters. The content of lysozyme in saliva of villagers who use biogas as energy source is 65,438 0.3 times higher than that of villagers who burn coal, and the average value of carboxyhemoglobin is 28% lower than that of residents who burn coal, indicating that using biogas as energy source can not only reduce indoor air pollution, improve air quality, but also improve human health.

So we say that biogas digesters are magic pools, processing plants, cornucopia, cash cows and environmental beauticians.

Biogas pool is just a magical pool: it can turn waste into treasure, turn harm into benefit, and one pool can be used for multiple purposes. Does not occupy space, is convenient to manage, and has a wide range of comprehensive uses; Biogas pit is just a processing plant: it can continuously produce clean energy, high-quality and efficient organic fertilizer and high-quality livestock feed; Biogas pit is just a cornucopia: it can collect waste and turn it into treasure. As the saying goes, there is no waste in the world. In fact, human and animal manure, plant straw, slaughter wastewater, bean product wastewater, starch wastewater and distillery waste mash are all treasures of biogas digesters. Collect the waste, turn it into treasure, and sell it to buy any treasure in the world. Biogas digesters are just cash cows: they can make money every day. As long as you manage carefully, you will save a lot of money every day. Building large-scale biogas digesters can directly sell gas to make money, or use biogas to generate electricity and sell electricity into the power grid to make money. Biogas digesters are just environmental beauticians: treating and purifying courtyard pollutants through manure purification function; Households with biogas digesters can change the "dirty, chaotic and poor" sanitary appearance of the courtyard; The whole village has biogas digesters, which can change the environmental appearance of the whole town; The county has biogas digesters, which can change the environmental outlook of the county.

What is biogas? The bubbles from Wang Kezi, septic tanks with water and mud in ditches and rivers are biogas. If you poke a big bubble with a match, it will smoke and catch fire. Pure "biogas" is called methane. In fact, 60% of the biogas produced by our biogas digesters contains methane gas, and the remaining 40% carbon dioxide accounts for the vast majority, with a small amount of hydrogen, hydrogen sulfide, carbon monoxide, nitrogen and ammonia. Biogas is actually a mixed gas.

Before liberation, the first biogas digester was built in Shantou, China (1929). At that time, biogas digesters were built to open factories. A biogas pipeline led dozens of lights, which were much brighter than kerosene lamps at that time. At that time, people replaced foreign oil lamps with foreign lamps, which was a very magical thing.

After liberation, in the early 1970s, there was a shortage of fuelwood in rural areas, and the trees on the mountain were about to be cut down by mountain villages. In our plain area, our long-handled shovel for cooking is used to shovel the stubble legs in the lake. At that time, domestic biogas digesters were popularized in many places in China, and 7 million biogas digesters were built in a few years, which really solved many problems. The biogas digester built by indigenous method was described as "good use in one year, less gas production in two years and completion in three years". At the same time, due to the backward biogas production technology at that time, the raw material was mainly straw, which had some shortcomings, such as unable to produce gas regularly, difficult to discharge, and needing overhaul in 3-5 years, so a large number of biogas digesters were scrapped in the later period, which once caused some people to question biogas technology.

Now the pool is built by specially trained technicians from the country, which can produce gas every year and is convenient to manage. 15-20 years without major maintenance, and the safety problems are greatly reduced.

There are three purposes to build biogas digesters now. One is to liberate rural women from the miserable environment of smoky fire, spicy eyes, sour nose, a handful of firewood at the bottom of the pot and a handful of noodles on the pot, and burn biogas to clean energy, so that rural people can make clean meals with a twist. The second is to protect the environment. Although farming in rural areas has increased, malodorous diseases have also increased, which directly threatens people's lives. Now, building biogas digesters with different sizes according to the amount of aquaculture can solve environmental problems. Third, the production of green food, biogas residue as fertilizer to improve the soil, crop diseases and insect pests are less, more nutritious than the grain, fruits and vegetables produced by fertilizer, and taste good. At the same time, feeding pigs, chickens, sheep, cattle and other animals with biogas slurry has less diseases, bright meat color, comprehensive nutrition and better taste.