In addition to composting organic material, NALG applies the tunnel composting technique for biological drying of other waste streams containing organic material. The organic part will be composted. During composting the organic part produces heat, which is applied directly for the drying process. This biological drying has the following advantages:
Due to reduction of the organic parts, the material does not smell annoying anymore. Pathogens such as Salmonella, E.Colli bateria, and viruses are eliminated or reduced in high quantities
The activity of the organic fraction can be reduced for a large part. This results in odourless storage of the produce that does not attract animals;
The process is aerobic, so there is no methane production. Also a large part of the carbon is stored with the effect that the CO2 emission is reduced. Both are in favour of the environment and of the Kyoto treaty;
There is a volume and weight reduction, up to a 35%, so cost of storage and transportation are also reduced significantly;
If required, the material can be further recycled due to the fact that it is dried;
The caloric value increases, so incineration gives more energy, lower emissions and fewer ashes;
Facilities for biological drying can be build on a local level.
The aerated floors are constructed with spigotpipes that are designed as per aeration need and floor pressure requirements. These spigotpipes are available in 2 different dimensions, depending on the amount of aeration that is needed. The floor can be driven upon with a front end loader. The floors can be indoor as well as outdoor. A NALG fan supplies a central ductwork with air. On this central ductwork several branches with individual motors and valves supplies the spigotpipes with air.
NALG is using aerated floors for the following purposes:
Composting of green waste;
Temporarily storage of organic material