by Rayen
Anaerobic waste treatment with biogas production is traditionally carried out in the fermentation of animal waste such as liquid manure or slurry. This waste can be mixed with other household waste, residues or waste from the processing of raw materials from the food industry http://max64.ru/.
Depending on the composition of the processed raw materials, a different level and energy value of the biogas yield can be expected. The amount of waste generated depends on the age and type of animals, as well as on the season. The average amount of biogas that can be obtained from 1 m3 of animal waste is estimated at 20-25 m3. A cost-effective amount in technical and economic terms is considered to be 30-35 m3. This amount of biogas can be obtained by mixing animal waste and household waste with other types of raw materials, which are characterized by a high content of dry organic matter, namely, food industry waste or plant matter.
The feedstock that undergoes methane digestion can be divided into three categories:
Agricultural: liquid manure, solid manure, energy crops, biomass residues, etc .;
Industrial: starch, slaughterhouse waste, dairy and sugar factories, pharmaceutical, cosmetic and paper industries;
Household: organic waste, municipal waste water, etc.
Fermentation material can be divided into main (fermentation of which can occur independently, without adding other substances) and auxiliary. The main fermentable raw material is considered to be manure, slurry, young grass, and the auxiliary one is waste from the processing of vegetables and fruits, organic waste, food residues, molasses, organic products that decompose naturally (biological), household waste, etc.
Animal waste (manure, droppings, etc.) - animal waste products obtained as a result of enzymatic, in particular microbial processing of feed by the animal body. They have a characteristic smell and consistency. Used as natural fertilizer or fuel.
The use of livestock waste with stall-free livestock maintenance is not advisable from the point of view of obtaining energy resources: the number of animals per unit area is so small, and the dispersion of livestock waste is so great that the delivery of the latter to enterprises for the production of energy resources from biomass - biogas stations, turns out to be economically and energetically unjustified measure.
A completely different situation is obtained when keeping animals in closed rooms. In this case, the amount of waste collected from a unit of area increases significantly, and the costs of collecting and shipping them are reduced.
The amount of manure from each type of animal and its composition depend on the diet and the duration of keeping animals in closed rooms (see table). The moisture content in manure varies between 60-85%.
The efficiency of methane production by fermentation of manure depends on the amount of carbon-containing matter in it that has not decomposed: the older the manure, the higher the degree of its preliminary decomposition and the less substances in it that have not decomposed and can be converted into methane. Methane production technology depends on the content of inert substances in animal waste: the more there are, the lower the methane yield per unit of waste mass.
With the energy conversion of ruminant waste in a biogas plant, instead of the expected methane yield of 0.26 - 0.30 m3 / kg of organic matter, only 0.13 - 0.15 m3 / kg of organic matter is formed as a result of the loss of a part of carbon-containing substances in the process of food digestion.
Depending on the composition of the processed raw materials, a different level and energy value of the biogas yield can be expected. The amount of waste generated depends on the age and type of animals, as well as on the season. The average amount of biogas that can be obtained from 1 m3 of animal waste is estimated at 20-25 m3. A cost-effective amount in technical and economic terms is considered to be 30-35 m3. This amount of biogas can be obtained by mixing animal waste and household waste with other types of raw materials, which are characterized by a high content of dry organic matter, namely, food industry waste or plant matter.
The feedstock that undergoes methane digestion can be divided into three categories:
Agricultural: liquid manure, solid manure, energy crops, biomass residues, etc .;
Industrial: starch, slaughterhouse waste, dairy and sugar factories, pharmaceutical, cosmetic and paper industries;
Household: organic waste, municipal waste water, etc.
Fermentation material can be divided into main (fermentation of which can occur independently, without adding other substances) and auxiliary. The main fermentable raw material is considered to be manure, slurry, young grass, and the auxiliary one is waste from the processing of vegetables and fruits, organic waste, food residues, molasses, organic products that decompose naturally (biological), household waste, etc.
Animal waste (manure, droppings, etc.) - animal waste products obtained as a result of enzymatic, in particular microbial processing of feed by the animal body. They have a characteristic smell and consistency. Used as natural fertilizer or fuel.
The use of livestock waste with stall-free livestock maintenance is not advisable from the point of view of obtaining energy resources: the number of animals per unit area is so small, and the dispersion of livestock waste is so great that the delivery of the latter to enterprises for the production of energy resources from biomass - biogas stations, turns out to be economically and energetically unjustified measure.
A completely different situation is obtained when keeping animals in closed rooms. In this case, the amount of waste collected from a unit of area increases significantly, and the costs of collecting and shipping them are reduced.
The amount of manure from each type of animal and its composition depend on the diet and the duration of keeping animals in closed rooms (see table). The moisture content in manure varies between 60-85%.
The efficiency of methane production by fermentation of manure depends on the amount of carbon-containing matter in it that has not decomposed: the older the manure, the higher the degree of its preliminary decomposition and the less substances in it that have not decomposed and can be converted into methane. Methane production technology depends on the content of inert substances in animal waste: the more there are, the lower the methane yield per unit of waste mass.
With the energy conversion of ruminant waste in a biogas plant, instead of the expected methane yield of 0.26 - 0.30 m3 / kg of organic matter, only 0.13 - 0.15 m3 / kg of organic matter is formed as a result of the loss of a part of carbon-containing substances in the process of food digestion.
