Delivered by trucks waste is discharged into the waste storage bin then picked up by a crane, discharged onto two rotor cutters and then transferred into the fine storage bin. Some sewage sludge is also delivered there.
Crane mixes waste and sewage sludge in order to obtain a homogeneous mixture and then transfers the waste into the feeding hoppers of the charging devices of the rotary kilns.The conveyors transport the waste from the hoppers to the feeding chute, consisting of a gas-tight slide gate valve (prevents air access to the kilns) and a chute. A feeding screw downstream the feeding chute conveys the waste into the pyrolysis kiln.
The waste pyrolysis takes place into two indirect heated rotary pyrolysis kilns with heated lengths of ~ 20 meters and an inner diameter of ~ 2.2 meters. Each kiln has a capacity of 3 tons per hour. Waste is thermally degraded using an indirect external source of heat at ~500 C in the absence of free oxygen supply. Solid residuals of the pyrolysis process are removed via a wet discharger. The pyrolysis gas is sealed from the atmosphere by the water level in the discharger. Metals are extracted by an overhead magnetic separator discharged into a container for recycling.
The volatile portion of the waste produces syngas, which is sent into the boiler, generating steam. Steam is used by a turbine for electricity generation (~ 2.2 MW).
The exhaust gas from the boiler is thoroughly cleaned in the emission control subsystem in order to achieve the full compliance with the emissions limits. The residual steam/condensate is used in greenhouses located in the neighbourhood.
The pyrolysis facility operation is monitored and controlled from the control room.
This pyrolysis plant with annual capacity annually 35000 tons of MSW practically demonstrates the most efficient and environmental friendly approach for the management of municipal waste.
This pyrolysis plants efficiently treats 8-10 tph of soil contaminated with mercury, organics (polycyclic hydrocarbons, mineral oil hydrocarbons, acid resins, chlorinated compounds (dioxins, furans, PCB), and other poisonous or dangerous like pesticides, cyanides, explosives.
Actual plant capacity depends on type of contamination.
After the inital screeening to separate big stones and other bulky objects, the contaminated soil is dryed and then sent to the pyrolysis kiln. Pyrolysis temperature depends on a contaminant.
Pyrolysis gas is then sent to combustion chamber. Flue gas is used for the pyrolysis gas heating.
Clean soil is unloaded from the pyrolysis kiln while gases, containing contaminants, are further thoroughly treated in the gas cleaning system comprised of both dry cleaning and wet scrubber units.
On-line monitoring of exhaust gases to the stack is provided. The facility is located in direct vicinity of living quarters. This pyrolysis plant demonstrates safe and reliable operation.
When required this pyrolysis plant also performs regeneration of a spent activated carbon