The facility has been procecessing up to 15,000 tonnes per year of green waste in windrows with the compost being used in agriculture in the vicinity. In response to landfill diversion targets in Gloucestershire, Rosehill Recycling has developed an in-vessel compost facility to process source-separated domestic bio-waste at the site. The inclusion of meat in the waste stream has required the facility to be up-graded to ABPR compliance. Celtic BioEnergy was selected to develop a twin barrier tunnel composting solution for the facility.
Weighbridge; 2 x JCB loading shovels with 3 cubic meter buckets; 2 x 75kW diesel driven ORGAMIX auger mixers for feedstock preparation and loading of in-vessel tunnels; Seven x 450 cubic meter concrete tunnels with recirculating air-flow; air cooled biofilter to treat odours from the tunnels. The entire process is controlled by a remote access computer and PLC.
Composting Process and Residence Time:
The feedstock is a mixture of household organics and green waste. The material is blended in the mixers and then loaded into the four barrier one in-vessel tunnels for 7-10 days of initial composting. Each batch is 100-120 metric tonnes. After the batches have achieved 60oC for 48 hours, the material is transferred to the three barrier two tunnels for an additional 4-6 days of in-vessel processing in accordance with the ABPR. After the twin barrier process, the material is transferred to a quarantine area for microbial testing prior to windrow maturation on the existing slab. After the curing period, the product is screened for distribution.