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Nutrient balance of a two-phase solid manure biogas plant

Schäfer, Winfried; Evers, Lars; Lehto, Marja; Sorvala, Sanna; Teye, Frederick and Granstedt, Artur (2005) Nutrient balance of a two-phase solid manure biogas plant. In: Stenberg, Maria; Nilsson, Hans; Brynjolfsson, Rikhard; Kapuinen, Petri; Morken, John and Søndergaard Birkmose, Torkild (Eds.) NJF Report, Nordic Association of Agricultural Scientists, 1 (2), pp. 43-46.

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Online at: http://www.greppa.nu/download/18.1dbe72f10750900a89800075/NJF+372+Proc+051109.pdf

Summary

So called "dry fermentation" prototype plants for anaerobic digestion of organic material containing 15-50 % total solids show added advantages compared to slurry digestion plants (Hoffman 2001): Less reactor volume, less process energy, less transport capacity, less odour emissions. However on-farm dry fermentation plants are not common and rarely commercially available. Recent on-farm research (Kusch & Oechsner 2004) and prototype research (Linke 2004) show promising technical solutions for dry fermentation batch reactors on-farm.
The Biodynamic Research Institute in Järna developed a two-phase on-farm biogas plant. The plant digests manure of dairy cattle and organic residues originating from the farm and the surrounding food processing units containing 17.7-19.6 % total solids. A new technology for continuously filling and discharging the hydrolysis reactor was developed and implemented. The output of the hydrolysis reactor is separated into a solid and liquid fraction. The solid fraction is composted. The liquid fraction is further digested in a methane reactor and the effluent used as liquid fertiliser. Initial results show that anaerobic digestion followed by aerobic composting of the solid fraction improves the nutrient balance of the farm compared to mere aerobic composting. Composted solid fraction and effluent together contain about 70 % of total input nitrogen and 94 % of input NH4. The manure that was merely aerobic digested contained about 51 % of total input nitrogen and 3.9 % of input NH4. Additionally anaerobic digestion improves the energy balance of the farm producing up to 269 l biogas kg-1 volatile solids or 1,7 kWh heat kg-1 volatile solids.


EPrint Type:Conference paper, poster, etc.
Type of presentation:Paper
Keywords:biogas, compost, nutrients, carbon, anaerobic digestion, dry fermentation
Subjects: Farming Systems > Farm nutrient management
Farming Systems > Buildings and machinery
Crop husbandry > Composting and manuring
Research affiliation: Finland > MTT Agrifood Research
Finland > MTT Agrifood Research > Agricultural Engineering
Related Links:http://composit.dimea.se/www/njf/site/seminarRedirect.asp?intSeminarID=372&p=1293, http://www.greppa.nu/download/18.1dbe72f10750900a89800075/NJF+372+Proc+051109.pdf
Deposited By: Schäfer, Dr. Winfried Christian
ID Code:6542
Deposited On:15 Dec 2005
Last Modified:12 Apr 2010 07:32
Document Language:English
Status:Published
Refereed:Peer-reviewed and accepted

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