environmental impact statement kilmainhamwood compost facility ...

5361- Kilmainhamwood Compost Facility Extension- EIS
Hanger composting systems and continuous flow composting systems are unsuitable due to the
difficulties (previously outlined) associated with satisfying Animal By-Product conditions stipulated by
the Department of Agriculture, Fisheries and Food.
Overall a tunnel or bay composting system is recommended for the extension to the Kilmainhamwood
Compost facility due to the modularity of the system, its inherent flexibility, the limited need for
mechanical plant, its robustness and low maintenance requirements. On the basis of the proven track
record of the existing indoor bay composting system (which has operated successfully since September
2006) to produce a high quality compost product in a controlled environment with minimal impact on the
environment, it is recommended that additional composting bays are constructed to facilitate the
extension to the facility.
In order to optimise the volumes of process air that require treatment, it is recommended that both the
existing and additional compost bays are enclosed by way of a concrete roof and canopy door, thus
significantly reducing the volumes of process air that will require treatment. Only the volume of air
between the composting mass and the roof of each composting bay will require intensive odour
treatment as opposed to the entire volume of the facility building.
3.3 ALTERNATIVE ODOUR ABATEMENT TECHNOLOGIES
Thorntons Recycling considered a number of alternative odour abatement technologies during the
preliminary design of the extension to the Kilmainhamwood Compost Facility. The following
technologies were examined:
• Thermal Oxidation;
• Chemical Scrubbing and biofiltration;
• Carbon absorption;
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Thermal Oxidation;
Thermal oxidation is a highly effective means of destructing concentrated odorous gases. It is generally
accepted that destruction of odours is achieved when they are held at around 1000 o C for 0.3 seconds.
Thermal oxidation involves the direct combustion of odorous gases. In an odour abatement application
for a composting facility, the thermal oxidation process requires fuel to maintain the operating
temperature at a level suitable for destruction of odours. The main disadvantage of thermal oxidation for
the treatment of odours at composting facilities is the significant operating cost due to the consumption
of fuel as part of the process.
Chemical Scrubbing and Biofiltration
Biofiltration technology can be used to treat a variety of biodegradable, water soluble contaminants. In a
biofilter, the odour contaminants are solubilised from the vapour phase into an aqueous phase on the
surface of an organic medium such as woodchips, compost, mulch or peat. The compounds are then
degraded by the bacteriological population on this media. Biofilters are very effective at removing
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