New Acerra WtE plant - Fisia It · 2018. 5. 15. · Acerra WtE plant Acerra WtE plant is one of the...
Transcript of New Acerra WtE plant - Fisia It · 2018. 5. 15. · Acerra WtE plant Acerra WtE plant is one of the...
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Acerra WtE plant
Acerra WtE plant is one of the largest in Europe, being capable to dispose 600.000 tons/year of selected MSW and generates 600 million kilowatt-hours per year of electric power, a quantity enough to satisfy the needs of 200.000 families.
The plant is composed of three identical combustion and flue gas treatment lines, operating in parallel, of a power generation section and of common services, as detailed here below (see also plant block diagram):
MSW receiving section
Number of units: 1 (common to the three lines)
composed of :
Weighing station
MSW storage bunker
MSW bales breaking system
Combustion and flue gas cleaning
Number of lines: 3
Configuration of each line :
Moving grate furnace integrated with boiler
Semi−dry absorption reactor for acid gas removal (reagent used : lime milk)
Activated carbon powder injection system
Bag fabric filter no. 1 for dust removal
Lime and activated carbon (mixed reagent) injection system
Bag fabric filter no. 2 for dust removal
Flue gas reclycling facility from bag filter no. 2 to bag filter no. 1
SCR DeNOx reactor
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Extraction ID (induced draft) fan
Emissions monitoring systems
110 m high stack
Power generation section
Number of units: 1 (common to the three lines)
composed of :
Steam turbine and generator
Air−cooled condenser
Thermal cycle equipment
Auxiliary systems (demi water production plant, chemicals dosing systems)
Electric substation
Diesel emergency generators
Lime storage and milk preparation system
Number of units: 1 (common)
composed of :
CaO storage bins (no. 2 units)
CaO dissolution and lime milk preparation (No. 2 lines in parallel, one of which in stand−by)
Lime milk feeding system to absorption reactors
Activated carbon and mixed reagent storage and dosage system
Number of units: 1 (common)
composed of :
Activated carbon storage bin
Mixed reagent storage bin
Pneumatic feeding system
Ash inertization plant
Number of units: 1 (common)
composed of :
Dosing and mixing system
Ash and chemicals storage system
Auxiliary systems
Wastewater treatment plant (biological + chemical−physical)
Fly ash collection and conveying to storage bins
Bottom ash storage system
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Operation parameters
Main plant operation parameters at nominal operating conditions are summarized here below:
Furnaces:
Number no. 3
Unit capacity t/h RDF 27,07
LTV of MSW kJ/kg 15070
Unit thermal input MW 113,33
Boilers:
Number no. 3
Characteristics of produced steam (each line)
state superheated
pressure bar abs 90
temperature °C 500
flowrate t/h 126,5
Flue gas cleaning:
Number of lines no. 3
Unit flowrate per line Nmc/h 200 000 (about)
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Chemicals used :
Ca(OH)2 in aqueous suspension (lime of milk), in absorption reactor
Activated carbon powder, injected upstream bag fabric filter no. 1
“Mixed reagent” (mixture of Ca(OH)2 and activated carbon), injected upstream bag fabric filter no. 2
Ammonia solution 25% , in SCR DeNOx system
Electric power production:
Characteristics of steam fed to turbine :
state superheated
pressure bar abs 88
temperature °C 498
flowrate t/h 379,5
Electric power at generator terminals MW 106,5
Highlights of plant operation
Plant first firing: March 26th, 2009
Start of plant commercial operation: September 2009.
The guaranteed emission values of Acerra WtE plant are far below the maximum allowable by law.
The measured emission values during Acerra plant operation showed to be well lower than guaranteed values , giving evidence of the efficiency of the design and of the adopted technological solutions.
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Acerra WtE plant block diagram
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Guaranteed emission limits vs. max. permissible limits