Danish Pig Research Centre: Annual Report 2010: Biogas and Slurry Separation
The Bioenergy Site, November 7, 2011
The 2010 annual report from the Danish Pig Research Centre describes the costs and benefits of biogas production and pig manure separation.
Break-even analyses of biogas systems based on pure livestock manure revealed that the price of biogas produced on electricity should be raised from approximately DKK0.76 to DKK1.10 per kWh. In Denmark, biogas systems receive slurry from livestock farmers, and they also collect the degassed biomass. Dry matter content of the slurry contributes slightly, but positively to the gas yield.
To obtain a sufficiently high gas yield, a range of purchased energy compounds, sludge and industrial waste are used. As a result, gas yield increases significantly compared to using slurry only. However, the consequence of comprehensive extensions of the biogas sector based on livestock manure in Denmark would be that in particular pig slurry would need to be concentrated as biogas facilities based on 100 per cent livestock manure will otherwise not be profitable.
This may be solved through concentration of the dry matter content of slurry.
Transport of one tonne slurry one kilometre costs about DKK1. If slurry separation costs DKK18 per tonne, the remaining 40 per cent of the harmony area of a pig farm must be located more than 55km away in order for slurry separation to be economically more attractive than regular slurry handling.
For the individual farm, however, the break-even distance may be somewhat less, depending on slurry agreement etc. For most pig producers, slurry separation will increase costs for slurry handling. The break-even analysis, therefore, assumes that the biogas systems pay the costs of slurry separation.