environmental impact statement kilmainhamwood compost facility ...

5361- Kilmainhamwood Compost Facility Extension- EIS
Salmonella, the entire mass of composting material would require re-processing under the
requirements of the Department of Agriculture, Fisheries and Food. Such an event would have
significant financial and operational consequences. Hence, hanger systems are becoming increasingly
undesirable for the composting of waste. In addition, hanger systems require the odour abatement
system to process all the air space within the building in comparison to enclosed tunnel or bay systems
where only the process air within the tunnel or bay requires intensive treatment. As a result, hanger
systems demand significantly more energy per unit of compost processed in comparison to enclosed
tunnel or bay systems.
Tunnel and Bay composting systems
Tunnel and bay composting systems allow extensive process control, since the biowaste is composted
in relatively small tunnels or bays.
Various process parameters including aeration rates, air moisture and oxygen levels can be controlled
from a central process computer. In addition, due to the modular layout of tunnel or bay systems,
several units can be operated independently, which guarantees significant flexibility in treating different
biowaste streams independently at the same time. The optimally controlled process conditions
furthermore allow the composting to be executed in the shortest possible timeframe.
Tunnel or bay composting systems are ideally suited to satisfying the requirements of the Department
of Agriculture, Fisheries and Food with respect to the processing of Animal By-Products. Such a plant
which comprises of a number of tunnels or bays facilitates the processing of feedstock in a number of
‘batches’. Hence, in the event of a failed batch, the quantity of material that requires re-processing is
not significant. In addition, a failed batch can be easily isolated thereby satisfying hygiene requirements.
Continuous flow composting systems
In continuous flow systems the biowaste flows horizontally or vertically through a reactor while the
forced aerated composting process occurs. Well known systems includes the Wright Environmental
system. Continuous flow composting systems allow adequate control of the process conditions.
However, since the retention time in the reactor is relatively short (typically 12-14 days) an extensive
post-composting step is required.
For inspection purposes only.
Consent of copyright owner required for any other use.
A continuous flow composting system is not a ‘batch’ system, hence similar difficulties arise with
respect to Animal By-Products as previously noted for hanger systems.
Preferred Technology
As outlined previously, an outdoor system does not allow for the provision of process and emission
control measures which could lead to odour nuisances at or near the facility. The composting process is
dependent on the prevailing weather conditions leading to extended composting time requirements. In
addition the final quality of the product cannot be guaranteed consistently using an outdoor system and
Animal By-Product requirements cannot be satisfied. An indoor composting facility will therefore be
required.
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EPA Export 01-06-2010:03:55:52