The composting of organic waste is a proven and well developed technology. The tunnels are fabricated in concrete in different sizes and are equipped with an aeration floor developed by Ros Roca.

The organic material is charged into the tunnels by front-end loader or automatically with conveyors. For aeration each tunnel is equipped with a blower which is blowing air through the aeration floor to ensure an efficient oxygen supply of the microorganisms.

For charging or discharging the tunnels they are equipped with doors which are gas-tight to assure that no odour-loaded air can leak during the composting process. Usually the organic material is composted for two weeks in the tunnels. After that the organic material will be finally maturated by windrow composting. The process parameters like temperature, oxygen, carbon dioxide are measured continuously and are used to control the composting process. Odour-loaded air from the composting process is sucked off by ventilators and cleaned by scrubber / biofilter.