Compost Refining Parona | Pavia
Lomellina Energia SrlParona | Pavia - Italy
- System description: Compost refi ning
- Waste processed: Mixed municipal solid waste
- Plant capacity: 200,000 t/year
A compost refining system is used to separate inert and combustible material from the stabilized organic fraction produced in the composting building.
A rotary screen separates the flow of material into two differently-sized fractions. This screening enables the subsequent operation of two specific separators, suited to the size of the treated material. An air knife separator treats the larger size fraction. Its air flow separates the light materials from the heavy ones. The light fraction, which has some heating value, joins the main flow of RDF to be used for power generation. This helps in reducing process rejects and maximizing fuel recovery. A fluidized-bed separator treats the small size fraction and separates inert materials - consisting mainly of glass and stones - from the compost. The fluidification of the material, essential for separation, is performed by blowing air through an oscillating table. The heavy rejects produced by the fluidized bed separator are collected together with those produced by the separator treating the larger fraction of stabilized material. The refined compost is sent to the storage building, where it is piled by means of a shuttle conveyor belt. To reduce dust emissions, a suction system is connected to hoods located above both separators. The sucked air is processed by two cyclones. The light material unloaded by the rotating air valves of the cyclones is also recovered as fuel.