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Why are biogas digesters abandoned in rural China? It's not banned, but it's rarely used?
Many years ago, it was popular in rural China to build biogas digesters for every household, and they also vigorously promoted and issued various political subsidies, claiming that biogas digesters could help farmers solve gas problems such as cooking, laundry and boiling water!
But now, self-built biogas digesters in rural areas have been abandoned, and the policy does not prohibit them, so why is no one using them? What are the hazards of self-built biogas digesters in rural areas?
The biogas digester has a long history of development in China's history, and it has always been the crystallization of the wisdom of Chinese farmers from today's rise to the tranquility of the century.
A biogas digester works by the fact that under specific conditions of temperature, humidity and pH, organic matter is broken down by microbial action in an anaerobic environment to produce combustible gas.
The main component of this flammable gas is methane.
Due to the large amount of gas produced, the increase in biogas leads to an increase in the vapor pressure in the digester, and when the valve is opened, the biogas flows out and is ignited by a flame for people to burn and cook.
The earliest biogas industry in China began in Shantou, Guangzhou, in the 20s of the 20th century. The founder, Luo Guorui, a native of Hsinchu County, Taiwan Province, built China's first biogas digester next to his kitchen in Shantou for cooking.
More than a metre deep underground, the digester has been passed down through three generations and has survived intact despite the city's constant changes.
Forty years after the first biogas digester in China, the role of biogas as a cooking fuel was introduced to the market. In Sichuan, China, as the country's first biogas digester pilot, farmers have used their own biogas digesters to solve their daily cooking fuel problems.
At the end of the 20th century, China made great strides in the development of biogas digesters. The containment conditions of the digester as well as the temperature, humidity and pH are all very good.
At that time, natural gas was expensive, and in order to solve the problem of farmers' cooking, self-built biogas digesters began to be promoted on a large scale.
Compared with conventional fuels, biogas digesters have irreplaceable advantages. At that time, the national gas distribution network was not yet able to cover the whole country, so the main fuel used by most people was still wood.
Burning wood produces a large amount of carbon dioxide, which seriously pollutes the atmospheric environment and even forms fog in severe cases.
In addition, the massive demand for firewood has led farmers to cut down trees en masse, leaving the country with a dwindling forest area and many plains becoming bare and inhospitable.
Large-scale deforestation can lead to soil erosion, and in severe cases, even natural disasters such as landslides, which is not conducive to the sustainable development of the ecological environment.
In addition to wood, the second largest fuel used by farmers at the time was coal, which, like wood, produced large amounts of carbon dioxide and polluted the environment.
Moreover, because coal is difficult to mine, it is expensive, and it is difficult for the average farmer family to afford.
However, the carbon dioxide content of biogas is much lower, and after the biogas digester is built, biogas can be produced for self-use, and the remaining biogas by-products can be sold to ** companies, increasing farmers' income, which can be described as killing two birds with one stone.
Under the influence of this concept, China's self-built rural biogas digester began its own development period. Before the 21st century, there were about 8.48 million biogas digesters in rural China.
In the 21st century, the number of biogas digesters in China's rural areas has continued to increase, from 2000 to 2008, the number of biogas digesters in China reached a staggering 42 million in just 8 years.
The rural biogas digesters built by farmers in China have indeed helped solve the problems of more than 200 million farmers making fires for cooking and boiling water for heating, but why did the biogas digesters decline rapidly and no longer prosper in a short period of time?
2008 was the peak season for rural digester use, and before that, the number of biogas digesters nationwide was growing at a rate of 17% per year.
However, since 2009, the number of biogas digesters in China has continued to decline, and the rate of digester dismantling remains high. As of 2016, there were fewer than 1 million biogas digesters still in use in the country.
Official policy does not prohibit the construction and use of biogas digesters, and the failure of the digester market has exacerbated the problem.
One of the reasons digesters are on the verge of extinction is that they are not as simple and convenient as they seem.
Initially, when biogas digesters were widely promoted, they were advertised as stable in quality, simple in structure, and could be used permanently once they were built, thus getting rid of dependence on fuel.
However, the reality is that the quality of digesters varies across the country due to different levels of construction and materials. In addition, the proper use and maintenance of a digester requires a certain level of expertise, which the average farmer does not possess.
As a result, most digesters in rural areas are built according to drawings and their own expertise, and may work well at first, but over time, the digesters start to experience problems such as leakage, and the ability to produce biogas decreases dramatically.
The normal use of a digester is not only about building a solid, but also about mixing raw materials to achieve the correct temperature and pH, but the average farmer may not even have the equipment to test temperature, humidity and pH, and may not be aware of the various gases contained in the digester.
In this case, if the farmer wants to continue to use the digester, he must pay for professional maintenance and cleaning, which is time-consuming, laborious and costly, and over time, people's preference for the digester will gradually fade.
The second reason for the cancellation of the digester is that with the development of China's economic level, the fuel ** has been declining; At the same time, China's infrastructure projects are in full swing, and natural gas has become simple to access the household.
In addition, as China's urbanization deepens, the rural population has begun to migrate to cities. Urban households are no longer equipped to build biogas digesters.
Finally, rural biogas digesters have serious safety risks.
Since a large number of rural biogas digesters are built by residents themselves, the technical level and safety awareness of farmers are not up to standard. In addition, there were no strict audit standards during the construction process, and a large number of substandard digesters were used.
The existence of self-built digesters in rural areas is as dangerous as a ticking time bomb. If the fuel leakage is caused by the residents' carelessness, the open flame will occur violently, causing immeasurable economic losses to the owners, and even endangering lives.
Therefore, in the context of the changing times, self-built biogas digesters in rural areas are destined to be eliminated. However, the biogas digester is not useless, and its advantages such as low cost and low environmental pollution are irreplaceable even in modern society.
So, in today's new energy prevalence, what is the development prospect of biogas digester? How should China continue to develop green energy?
Although there are some problems with self-built rural biogas digesters, they should not be completely abandoned, and the key is to change the application scenarios.
The construction of biogas digesters in China must be based on laws, and biogas digesters must be transformed and upgraded from farmers' own use to commercialization.
In the future, the development of biogas digesters should not only be used as a fuel production mode, but should be effectively combined with agricultural development, and agriculture and biogas digesters should be developed into large-scale and intensive agricultural industries like the Western agricultural system.
In addition to biogas, China must also develop other new energy industries to adapt to the global wave of green energy development.
For China, water resources and wind energy resources are new energy industries in which we have advantages.
Due to the presence of the Yangtze and Yellow rivers, China has built a large number of hydro dams, especially in the southwestern provinces of Yunnan, Guizhou and Sichuan, which account for 80% of the country's water resources.
At present, China's hydropower resources have generated a total of 300 million kilowatts, and China's total hydropower resources are second only to coal, and the development potential is unlimited.
In addition to hydroelectric power, our wind energy also has great potential.
Implementation of China's wind power industry"Land and sea co-ordination"Development strategy, as of 2021, it will exceed 3100 million hours, accounting for one-third of the global wind power market, wind power generation for 12 consecutive years in the world's first.
In addition, solar energy is also one of the most respected new energy industries in China.
Compared with traditional coal power, wind power, hydropower, its total energy is larger, it can be said to be inexhaustible, and even according to the document released by the International Energy Agency, if solar energy substitution is implemented from today, then by 2050 the world will achieve the feat of net zero emissions of polluting gases.
China is the world's largest country in the photovoltaic manufacturing industry, and the production of photovoltaic installation parts has also brought hundreds of millions of yuan of annual output value to China.
As the global green concept continues to deepen, China also needs to vigorously develop the hydro, wind and solar energy industries and promote the reform of the national energy model.
Biogas digesters, with their advantages of low cost and production of ecological fuels, have been vigorously promoted in China in the 21st century, with the largest number reaching 43 million in thousands of households. However, due to its difficulty in maintenance and serious safety hazards, it will be eliminated in a few years.
Although there are some problems with biogas digesters, they still have huge market potential if they can be combined with agriculture and make full use of their ecological advantages.
In the future, biogas digesters may become a useful resource in agricultural production, providing farmers with renewable energy and reducing environmental pollution. This innovative combination not only solves the drawbacks of biogas digesters, but also has the potential to make a greater contribution to sustainable development and environmental protection.
What are your thoughts on the expansion and rapid disappearance of biogas digesters, and which green energy sources do you think will dominate the market in the future?
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