In Vessel Composter, or IVC for short, is where the compostable packaging, food and garden waste is repeatedly super-heated, breaking the materials down and mixed together to create a nutrient rich compost, suitable for supporting our country’s crop production. This is where our packaging must go to get composted into compost!
The term ‘in-vessel composting’ covers a wide range of composting systems, all of which involve the enclosed composting of waste – allowin oxygen levels, temperature and moisture to be controlled.
IVC can be a one or two stage process: the Animal By-Products Regulations (ABPR), introduced in 2003 to reduce health and environmental risks, allow waste excluding meat to be treated in one stage but require waste including meat to undergo two stages.
In stage one, food and garden waste is firstly shredded to a uniform size and loaded into a bay or tunnel. Naturally-occurring micro-organisms, already present in the waste, start breaking it down. The process draws oxygen from the air and raises the temperature to the 60-70ºC, which is needed to kill weed seeds and pathogens. Compost is produced, with water vapour and carbon dioxide given off as by-products.
If needed (if the original waste includes meat), the material is transferred to a second ‘barrier’ to ensure the material is fully sanitised. The two stages each take between 7 days and 3 weeks.
The compost is then left to mature in an open windrow for approximately 10-14 weeks to ensure stabilisation. Screening takes place to produce different quality compost.