Acerra WtE plant plant block diagram MSW receiving section Combustion and flue gas cleaning

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1 Acerra WtE plant Acerra WtE plant is one of the largest in Europe, being capable to dispose tons/year of selected MSW and generates 600 million kilowatt-hours per year of electric power, a quantity enough to satisfy the needs of 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) 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 1

2 Extraction ID (induced draft) fan Emissions monitoring systems 110 m high stack Power generation section Number of units: 1 (common to the three lines) 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) 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) Activated carbon storage bin Mixed reagent storage bin Pneumatic feeding system Ash inertization plant Number of units: 1 (common) 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 2

3 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 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 (about) 3

4 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 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. 4

5 Acerra WtE plant block diagram 5

6 Guaranteed emission limits vs. max. permissible limits 6