Biogas plants for pig and cattle-breeding farms

Cow farm biogas plant

Manure (cattle or pig) is not a fertilizer itself. In order to become fertilizer it needs time (6-7 months). The longer manure is stored the more nutrients it loses.

Biogas technology allows production of natural fertilizer in a short period of time. Such fertilizer is reach in active elements and microelements.

Here are main advantages of bio fertilizers produced by biogas plant to be compared to manure and chemical fertilizers.

Organic fertilizer

Maximum ammonia preservation and accumulation. Within continuous process of manure storage (composting) 50% of ammonia is lost. Thanks to anaerobic digestion in biogas plant total ammonia N completely preserved in bio-fertilizer, besides dissolved ammonia NH4-N content increased by 10-15%.

Absence of weed seeds. 1 ton of fresh cattle manure contains up to 10 thousand weed seeds that are capable for germination even after they passed through animal's stomach. After biogas plant weed seeds lost 99% of their germinating ability.

Absence of pathogenic microflora. Animal manure can contain human and animal health hazard diseases: salmonellosis, ascariasis, intestinal diseases. Due to special treatment in biogas plant bio-fertilizer is almost free of pathogenic microflora.

Presence of active microflora. High level of organic matter humification serves as a powerful impact for soil microorganisms activation. Ammonia fixing and other microbiological processes are also considerably intensified.

No need for storage. Thanks to its form bio-fertilizer can be effectively applied without any preliminary storage and has affective result after injection into the soil.

Soil Nutrients wash-out resistance. During the season about 80% of chemical fertilizer is washed-out from the soils, hence the need of its annual application in big quantities. In the same time only 15% of bio-fertilizer is washed-out, that is why even in small quantities they will work 3-5 years longer then chemical fertilizer does.

Ecological soil impact. Chemical fertilizer makes considerable harm and pollution to soil and groundwater. Contrary bio-fertilizer is completely ecologically clear.

Biogas plants that use manure as feed stock are most simple and widespread in the world. Microorganisms that participate in digestion process get into the manure from the animal bowels so no additional injection needed. Also hydrolysis stage is not required.

Biogas equipment is of modular type and if farm is planning extension biogas plant capacity can be easily increased.

Biogas plant can help reduce volumes or construction scale of lagoons almost twice. Manure organic compounds are of colloid type that hinders water evaporation from substrate. Biogas plant reduces organics volume and fermented biomass separated. Liquid fraction almost does not contain organics and water easily evaporated.

In case big volumes of straw or sawdust are used as bedding it is better to detach them before manure is loaded to the biogas plant. Due to lignin content in straw and sawdust their digestion period makes 200 days that makes biogas plant investments very high and such materials do not give good biogas yields.

Sow with breech of 20-24 piglets (weight up to 30 kg) produces about 14,5 kg of manure per day. Fattening pig with weight from 30 to 110 kg produces about 3,5 kg of manure per day. For daily manure production from sow house figure of constant sow heads to be considered.

Economically viable set up biogas plant at pig farms where annual pigs turnover not less then 10 thousands (500 sows).

One dairy cow produces from 30 to 70 kg of manure per day. Biogs plant will be economically viable for farms with livestock not less then 300-400 heads of dairy cows.

One ton of cattle manure gives 60 m³ of biogas.
One ton of pig manure gives 65 m³ of biogas.

Biogas plants for pig and cattle-breeding farms

Plant peculiarities

The biomass feeding unit varies depending on manure humidity: liquid manure (85-98%) is pumped up, solid manure (75-80%) comes through screw charger. Liquid manure can be mixed with solid and pumped to bioreactor by pumping station.

The best option for livestock breeding complex is electricity and heat production from biogas. Even if complex has low energy consumption farm always has other production lines that needs electricity. Biogas also can be used directly for heating or as fuel for vehicles.