Biogas plantsIn recent times more and more attention is paid to alternative energy sources: solar radiation, tides and waves, and more. These can be attributed, and biogas. Biogas - energy carrier, which is a mixture of methane (60 - 70%), carbon dioxide (carbon dioxide) - (30 - 40%), small amounts of hydrogen sulfide, hydrogen, ammonia and nitrogen oxide (5%). Biogas composition can vary depending on the raw material (biomass), the microorganisms involved in the process, additives and physical factors. Biogas with 56% methane content has a power consumption of 20 MJ/m3, 62% - 22.7MJ/m3, 70% - 25 MJ/m3. In comparison, natural gas - 33.6 MJ / m3 diesel - 36 MJ /L petrol - 30.5 MJ /L.
From 1 m3 of biogas on average produced 2.1 kWh of electricity and 3.2 kW heat efficiency the system 0.8. Biogas can be used as a fuel for motor vehicles. For this purpose it is compressed and pumped into the cylinders similar to natural gas.
The main components of biogas - methane - is the result of anaerobic methane-producing microorganism of enzymatic reactions that convert chemical energy of biomass into energy of chemical bonds of methane.
Biomethanogenesis dependence on temperature.
The process of methanogenesis.
Animal waste from farms delivered to the biogas plant. The reactor is filled continuously via pump the raw material or filing auger, depending on the humidity of the substrate.
Waste vegetable matter such as grass, fed through the system to a solid substrate.
The reactor is a gas-tight, completely sealed reservoir. This construction thermally insulated to maintain a fixed temperature within the reservoir (52 ° C-57 ° C). In the reactor is located mixer that used to fully mix the contents.
The average duration of hydraulic sedimentation inside the reactor (depending on the substrate) is 20-40 days. During this time, the organic substances are transformed into microorganisms. As a result, formed two products: biogas and bio-fertilizer (composted and liquid).
The obtained biogas is stored in the gas holder - special container where equalize pressure and gas composition. From the gasholder gas is continuously is fed into the biogas filter then goes to the co-generator to produce electricity and thermal energy.
All the equipment is controlled by an automatic control system of a biogas plant and takes place in wide range of temperatures:
- 0 - 20 ° C - psychrophilic regime;
- 20 - 40 ° C - mesophilic;
- 40 - 60 ° C - thermophilic temperature regimes.
The rate of the fermentation process is highly dependent on temperature. Is fundamentally important that the higher the temperature, the faster the decomposition occurs and the higher gas production. This reduces the time decay.
Temperature - one of the important parameters that affect the metabolic activity of microorganisms and reproductive ability.
In industrial biogas plants using thermophilic mode (40-60 ° C, is optimal for animal waste - 52-57 ° C).