How Biogas Plant Works Complete Process with video

How Biogas Plant Works Complete Process with video

What is biogas?

With the help of bacteria, organic matter is decomposed to biogas under exclusion of light and oxygen. This process exists all over the world, e.g. at the bottom of lakes, in manure pits and on compost heaps. But to able to sensibly and efficiently use biogas, this process has to be controlled. In biogas plants, certain substrates are therefore used targetedly to be able to energetically utilise the biogas that was generated in a controlled manner.

For the most part, biogas consists of methane (50-75%) and carbon dioxide (25-50%). In this, the methane content in particular is an important indicator. Because the higher the methane content, the higher the energy content in the biogas.

The energetic utilisation of biogas is created by the burning of methane. One cubic meter (m³) of biogas with a methane content of 60% has an energy content of approx. six kilowatt hours (kWh). This is the equivalent of approx 0.6 l heating oil.

Why biogas?

Biogas has a multitude of utilisation option and is furthermore storable. As such, biogas is far superior to other renewable energies. Furthermore, biogas plants can generate power continuously and independent of sun, wind and water.

Good reasons for biogas

1. Biogas makes our energy production safer
2. Biogas does not just supply electric power but also heat
3. Biogas is a replacement for natural gas
4. Biogas can be used as fuel
5. Biogas is good for the climate and saves CO2
6. Organic residues can be sensibly utilised and do not need to be simply disposed of
7. Biogas manure can replace mineral fertiliser
8. Biogas plants can be utilised by industry and agriculture
9. Biogas strengthens rural areas and creates job

How does a biogas plant work?

1. Organic input materials such as foodstuff remnants, fats or sludge can be fed into the biogas plant as substrate.
2. Renewable resources such as corn, beets or grass serve as feed both for animals such as cows and pigs as well as for the micro organisms in the biogas plant.
3. Manure and dung are also fed into the biogas plant.
4. In the fermenter, heated to approx. 38-40 °C, the substrate is decomposed by the micro organisms under exclusion of light and oxygen. The final product of this fermentation process is biogas with methane as the main ingredient. But aggressive hydrogen sulphide is also contained in the biogas. A fermenter made of stainless steel has the clear advantage that it withstands the attacks of the hydrogen sulphide and is usable for decades. Furthermore, a stainless steel fermenter provides the opportunity to operation the biogas plant also in the thermophile temperature range (up to 56 °C).
5. Once the substrate has been fermented, it is transported to the fermentation residues end storage tank and can be retrieved from there for further utilisation.
6. The residues can be utilised as high quality fertiliser. The advantage: Biogas manure has a lower viscosity and therefore penetrates into the ground more quickly. Furthermore, the fermentation residue quite often has a higher fertiliser value and is less intense to the olfactory senses.
7. But drying it and subsequently using it as dry fertiliser is also an option.
8. The biogas generated is stored in the roof of the tank and from there it
9. is burned in the combined heat and power plant (CHP) to generate electricity and heat.
10. The electric power is fed directly into the power grid.
11. The heat generated can be utilised to heat building or to dry wood or harvest products.
12. Processing of biogas
13. Gas supply to the national grid or gas filling stations

Which substrates can be used?

For the generation of biogas, a multitude of organic substrates can be used. In the decision for or against certain substrates, the individual circumstances have to be taken into consideration. But the biogas yield of the different substances, which is decisive for the efficiency of the biogas plant, also has to be taken into consideration. Our employees are looking forward to providing you with advice regarding the optimal composition of your formula. At our own laboratory we can furthermore accurately determine the methane content of your substrates.

Below, you will find some substrates that our customers are already using successfully:

Agricultural Products

• Farm manure: e.g., cow manure, pig manure, poultry droppings, dung
• Renewable resources: e.g., corn, whole crop silage, grass, grains, beets
• Agricultural by-products: e.g., beet leafs, harvest residues

Industrial Waste

• Wastes of plant origin: e.g., contents of the biowaste bin, food remnants, fryer grease, slop/silage, draff/marc, pressed beet slices, potato peelings, grass clippings
• Wastes of animal origin: e.g., fat, animal blood, gastro-intestinal contents, slaughter waste
• Other substrates: e.g., sewage sludge

How can biogas be utilised?

Biogas is a real allrounder and with its multitude of utilisation options, it is the only renewable energy source that is flexibly utilisable.

Electricity is generated either through the burning of biogas at the CHP or through the utilisation of pre-processed biogas, the so-called biomethane. Biomethane is available everywhere through the natural gas grid.

When power is generated at a CHP, heat is created. This heat can be used for the heating of buildings, swimming pools or for drying wood. With an intelligent heat utilisation concept, the efficiency of the biogas plant is considerably increased.

Through various methods, biogas can be cleaned from the undesirable components and be fed into the natural gas grid as biomethane or also as so-called bio natural gas.

Biomethane as fuel provides a very high CO2 savings potential. With the additional of biomethane to natural gas, the CO2 output can be lowered considerably in comparison to gasoline. The biomethane of one hectare of corn permits a car to drive approx. 60,000 km.

WORKING

video credit- Enliveeducation