Background
The EU Landfill Directive is driving Local Authorities to reduce biodegradable waste input into landfill in order to minimise methane emissions (a potent greenhouse gas). Furthermore, the EU and UK Governments have set stringent recycling targets for Municipal Waste whilst also implementing the Animal By-Products Regulation (ABPR) 2005 in order to minimise the likelihood of disease outbreaks such as Foot and Mouth. For these three reasons, In-Vessel Composting is a vital tool in the management of Biodegradable Municipal Waste.

In-Vessel Composting
By source separating Municipal Waste into Garden Waste, Kitchen Waste and possibly Cardboard, up to 64% of waste could be diverted from landfill. To treat this waste to ABPR standards, a composting system must be secure from possible disease transmission. By utilising the natural composting process, the biodegradable waste can be reduced in weight by up to 60% and converted into a soil conditioner rich in nutrients and humus. In-Vessel Composting allows this to happen in a practical, sustainable and efficient manner.

The Agrivert In-Vessel Composting Tunnel
At the heart of the Agrivert system is the Agrivert tunnel. Designed over 10 years ago by Biodegma in Germany, the tunnel has been developed to meet market demands. The design is simple yet precision engineered and is made only of corrosion-free materials. There are no moving parts within the tunnel, the roof opens for loading/unloading by loading shovel and the Gore-Tex© membrane acts as a very simple but extremely effective odour and bioaerosol barrier.

Process
Waste enters the Reception Building and is shredded. Waste is transferred by loading shovel to Stage 1 tunnels to be aerated for 2-3 weeks, achieving a guaranteed 60°C for 48 continuous hours to comply with ABPR. Sanitised compost is transferred by loading shovel from Stage 1 tunnels to Stage 2 tunnels where the programme is repeated. Stabilised compost is transferred by loading shovel from Stage 2 tunnels to the Maturation Pad. The Matured compost is screened, oversize returned back through the plant, plastic removed and the finished compost recycled to amenity or agricultural use.

ABPR
The Agrivert In-Vessel Composting System rigorously adheres to the requirements of ABPR by using a dual barrier system of tunnels, fresh air ventilation for optimum temperatures and separated operating areas.

Waste Specification
A very wide spectrum of waste can be processed within the category of Kitchen Waste, Green Waste or Cardboard and the Agrivert In-Vessel Composting System is very forgiving towards ratios and contaminants.

Pedigree
The original Biodegma plant began operating over 11 years ago and the same plant continues today to be applied on a successful commercial basis. Since then a further 30 plants have been constructed across Europe and this system is used in treating 670,000 tonnes per year of organic waste.