First of all, from the policy point of view, the national subsidy for small biogas falls on the construction of biogas digesters. Due to the lack of supervision, a number of low-priced and inferior biogas digesters were born to obtain state subsidies. Although it has been used all the time, it never refuels. Biogas is used when it is produced, and it is idle when it is stopped. In addition, due to the serious quality problems of workers' construction, farmers don't know how to manage it correctly, and they can't popularize it on a large scale. And with the rural society getting better and better, farmers' friends have more and more choices, which are no longer limited to the choice of biogas digesters. For convenience and cleanliness, more people will choose to use new energy sources such as natural gas and liquefied gas. Therefore, after weighing the pros and cons, farmers will naturally not choose to use more troublesome biogas.
Secondly, the raw materials for biogas production are no longer sufficient. Anyone with a little common sense knows that biogas needs methanogenic bacteria to ferment, and methanogenic bacteria need animal manure and crop straw as raw materials. However, as more and more young people from rural areas go to work in cities, fewer and fewer people are farming and breeding in rural areas. Instead, they just turn on a machine and finish these things, which not only improves efficiency, but also saves time and effort. The raw materials needed by biogas digesters are naturally less and less. In this case, biogas digesters can only be eliminated! Moreover, the safety of biogas digesters is not enough, especially in hot summer. A large amount of biogas is like a time bomb, and it is dangerous to think about it.
Then, the defects of biogas digester itself: limitations, expensive maintenance in the later stage. Everything is not perfect. You should know that biogas digesters are not like liquefied gas or natural gas we use, and they are available at all times. After they are used up once, they have to wait for several hours before they can be used again. Generally speaking, it is inconvenient, not to mention the maintenance cost of biogas digesters is very expensive. Even if the biogas digester was built with high subsidies from the state at the beginning, the use of biogas digesters basically does not cost money, but the later maintenance makes people with low income a headache! Some people even think that using natural gas and liquefied gas for maintenance is better, which is not only convenient, but also relatively safe and clean.