Biogas - is formed as a result of organic substrate fermentation. It is decomposed by hydrolysis, acid and methane-forming bacteria. Mixture of gases produced by bacteria is combustible, as it contains a large percentage of methane. Biogas uses a variety of waste as raw materials. Technology has moved so far that it makes it possible to obtain biogas from virtually any raw material of organic origin. However, its different species have different dry matter percent per kilogram, biogas yield and methane content in it. That is why the type of waste plays a big role in the calculation of important technical and economic indicators. Compliance with the temperature regime plays a very important role. The formation of biogas in nature occurs at temperatures from 0 to 90 ° C. However, the greatest efficiency of the process can be achieved by maintaining a constant temperature and if the bioreactor producing gas is thermally insulated.
Purpose of the technology: obtaining gas, heat and electric energy from agricultural waste and manure.
The training video shows a biogas plant at the Denis Ten`s eco-farm from the Almaty region of Kazakhstan. A household biogas plant with a volume of 10 m3 allows you to receive heat and gas from agricultural waste, bird droppings and manure of sheep and goats. The farmer uses the resulting gas to heat a house of about 100 m2, heat water and cook in the kitchen. The biogas installation for thermal insulation is covered with a dome on top, inside which sensors are installed to control the bioreactor, part of the room under the dome is used as a greenhouse, and an aquarium for aquaponics is also located there. The most important product, according to Denis Ten, is not only the biogas plant produced - gas, methane, but the remainder of the fermentation of the organic substrate, which is a valuable organic fertilizer. It is used for liquid feeding vegetables in the farmer’s garden and is the main product of the farm for sale to gardeners and farmers, developing a business in organic farming. For countries where livestock and poultry farming are developed, the problem of processing manure, bird droppings and biological waste is quite relevant. If livestock waste is traditionally used as fertilizer in the fields, poultry litter, due to its toxicity, worsens the environmental situation and is therefore used to produce gas in biogas plants, or for the manufacture of fuel pellets. Many agricultural enterprises and farms, especially poultry farms, can be provided with electric and thermal energy solely from their own resources and biogas.
In the context of climate change, one of the adaptation strategies in the energy sector may be the development of energy supply and heat supply to households based on their own resources. In this case, diversification of energy sources, introduction of biogas, will serve more efficient use of agricultural waste and will help mitigate the vulnerability of farmers to the adverse effects of climate change.