Oslo / Norway Energy-from-Waste Plant - Hitachi Zosen Inova AG

Oslo / Norway Energy-from-Waste PlantKA3 in Oslo – latest process technology providesmaximum energy recuperation.With the expansion of the energy-from-waste plant at Klemetsrud by a third train, the overall capacityof the plants in the Oslo suburb rises to an annual capacity of 320,000 tonnes. The new plant train,called KA3, with a combustion performance of 20 t/h and a heating value of 12 MJ/kg,is designed for maximum recovery of heat and electricity production.Energy-efficient, economical and environmentallyfriendly– these were the requirements stipulatedby the City of Oslo, the “Energigjenvinningsetaten”(EGE), for the additional train in the Oslo suburbof Klemetsrud. In mid-2008, Hitachi Zosen Inovawas selected supplier by offering the mostpersuasive solution in terms of the concept andexperience in the construction of energy-fromwasteplants .The energy-from-waste plant is based on HitachiZosen Inova’s firing technology using the provenHitachi Zosen Inova reciprocating grate. Flue gasesare efficiently cleaned using a process based on awet scrubber. The energy is used to directly supplylocal district heating and electricity companies.Optimum combustion with energy extraction.The waste material stored in the bunker is conveyedinto the charging hopper of the combustionsystem via loading grabbers. In the combustionchamber, the reciprocating grate that comprisesfive individually-controllable zones ensuresoptimum combustion thoughout the variouscombustion stages. The first two water-cooledgrate zones provide the greatest degree offlexibility with regard to the heating values ofthe waste material.The recovered heat from the water-cooled grateis used to pre-heat the primary air. In the postcombustionchamber, above the grate, secondaryair and recirculated flue gas is injected tangentiallyat high speed. This guarantees the intensivemixture and excellent combustion of the gases.The energy released is transferred to the watersteamcycle in a subsequent four-pass boiler.Efficient cleaning of flue gas.Multi-stage flue gas cleaning ensures the safeseparation of all pollutants to maintain the lowestemissions values. The plant has been designed forlow operating material costs and maximum energyrecuperation.In a first step, 99% of dust and heavy metals thatare contained in the flue gas are removed in theelectrostatic precipitator.Both before and when inside the wet scrubber,dioxin compounds and mercury are adsorbed vialignite coke and are discharged with the scrubberwater. The acidic pollutant gases and heavy metalsare separated in the first two stages of the 4-stagescrubber. Sulphur dioxide is dissolved in the neutralstage, and the remaining fine dust particles andaerosols are separated via a ring jet stage (venturiprocess). The fourth scrubber stage provides a safeguardin the event of high levels of pollutants andalso allows heat recovery via flue gas condensation.

302312354961211781013292526 2714151617282018211922©24Waste receivingand storageCombustionand boilerFlue gas treatmentEnergy recoveryResidue handlingand treatment1 Tipping hall2 Waste pit3 Waste crane4 Feed hopper5 Ram feeder6 Hitachi Zosen Inovagrate7 Bottom ash discharger8 Primary air fan9 Primary air distribution10 Secondary air fan11 Secondary air injection12 Four-pass boiler13 Electrostatic precipitator14 Economiser 115 Quench16 Wet scrubber (4 stages)17 Flue gas reheater 118 Gas/gas heat exchanger19 Flue gas reheater 220 SCR-Catalyst21 ID-Fan22 Economiser 223 Stack24 District heating system25 Extraction condensationturbine26 Hot water condenser27 Waste water tanks28 Waste water treatment29 Ash conveying30 Ash siloNitrous oxides are decomposed into their approximatecomponents of air and water by the additionof ammonia solution. In the catalytic converter,dioxin compounds are broken down and reducedto the lowest threshold values.As a special feature in KA3, two economisers – oneupstream of the wet scrubber and one after thesuction draught – provide optimised recovery ofthe energy contained in the exhaust gas. Beforethe cleaned flue gas leaves the plant, a measuringsystem checks compliance with the admissibleemissions values.The waste water cleaning system comprises severalstages and cleans the scrubber water, which then ischannelled into the drainage system.Energy for the region.Klemetsrud KA3 is designed for optimised energyrecovery. The plant produces electricity and districtheat from steam recovery in combustion. Conversiontakes place in a turbine generator comprising anextraction-condensing turbine with regulatedlow-pressure extraction and taps for district heatextraction.

Hitachi Zosen Inova AGHardturmstrasse 127P.O. Box 6808037 ZurichSwitzerlandPhone +41 44 277 11 11Fax +41 44 277 13 13info@hz-inova.comwww.hz-inova.comOslo / Norway Energy-from-Waste PlantGeneral project dataOwner and operatorEGE Oslo KommuneStart of operation 2011Total investmentEUR 350 millionScope of Hitachi Zosen Inova AG Entire combustion system, boiler, flue gas cleaning system, waste watertreatment, connection to district heating network, electrical systemsand the entire control systemPlant designHitachi Zosen Inova AGTechnical dataAnnual capacity150,000 t/aNumber of trains 1Throughput20 t/h (nom)Calorific value of waste8 MJ/kg (min), 16 MJ/kg (max), 12 MJ/kg (nom)Thermal capacity66.7 MWWaste typeMunicipal and commercial wasteCombustion systemGrate typeHitachi Zosen Inova grate AR-12-10078Grate design3 rows with 5 zones per rowGrate sizeLength: 10.25 m, width: 7.8 mGrate cooling First two zones water-cooled (Aquaroll ® )BoilerTypeFour-pass boiler, horizontalSteam quantity per train77.2 t/hSteam pressure41.5 barSteam temperature 402°CFlue gas outlet temperature 170°CFlue gas treatmentConceptElectrostatic precipitator, economiser 1+2, 4-stage wet scrubber,exhaust gas reheating 1+2, SCR, dioxin separation, waste water treatmentFlue gas volume per train 120,000 Nm 3 /hFlue gas temperature85°C at stackDesignHitachi Zosen Inova AGEnergy recoveryTypeElectric power outputDistrict heatingExtraction-condensation turbine, connection to district heating systemMax. 13 MWMax. 55 MWResiduesBottom ashFlue gas treatmentApprox. 30,700 t/aApprox. 4,900 t/aSpecial featuresTwo economisers and condensationcooling for district heatingMax. 9 MW