热能与动力工程专业毕业设计论文翻译

文献阅读及译文ACOMPARISONSTUDYOFACFBANDPCFBASHCHARACTERISTICSK.M.SellakumarandR.ConnFosterWheelerDevelopmentCorporation,12PeachTreeHillRoad,Livingston,NJ07039,USAA.BlandForpersonaluseonlyinstudyandresearch;notforcommercialuseWesternResearchInstitute,365N.9thSt,Laramie,WY,82070,USAAbstract:Theadventoffluidizedbedcombustiontechnologyhasprovidedavenuesforenvironmentalissues-freeuseofalltypesoffossilfuels.WiththepotentialcommercialapplicationofPressurizedCirculatingFluidizedBedCombustion(PCFB)technologyintheverynearfuture,thereisaneedtounderstandthesimilaritiesanddifferencesinthecharacteristicsofsolidby-productsfromtheconventionalAtmosphericCirculatingFluidizedBedCombustion(ACFB)andthePCFB.SimilartoForpersonaluseonlyinstudyandresearch;notforcommercialuseACFBresidues,themaincomponentsinPCFBresiduesarefrom:-theinorganicconstituentsinthecoalandincorporatedsediments(Al,Fe,andSi),-theinorganicconstituentsinthecoalandincorporatedsediments(Al,Fe,andSi),Forpersonaluseonlyinstudyandresearch;notforcommercialuseAnd-sulfurreleasedfromthecoalduringcombustionthatiscapturedbythesorbent.However,theconcentrationofeachcomponentintheresiduesmayshowgreatvariations,dependingonthefeedsandoperatingconditionsintheunit.Ingeneral,theresiduesdischargedfromPCFBunitswiththesametypesoffeedsandsulfurretentionshouldhavearelativelylowercontentofcalciumbutahighercontentofcoal-derivedconstituentsthanthosefromACFBunits,becausealowersorbentfeedisrequiredforpressurizedsystems.Also,thesorbent-derivedcomponentsintheresiduesfrombothsystemsaredifferentduetothevarioussulfationmechanismsunderatmosphericandpressurizedconditions.Forpersonaluseonlyinstudyandresearch;notforcommercialuseAshsamplesfromthecommercialACFBplantsandtheFosterWheeler10MWthPCFBpilotplantinKarhulahavebeenusedinthisstudy.Inthispaper,theashcharacteristicsandwhereonetypeofash-ACFBashorPCFBash–hasbetterapplicationovertheotheraredescribed.INTRODUCTIONCFBcombustionhasproventobeoneofthemostpromisingtechnologiesforburningawiderangeofcoalsandotherfuelsandhandlingwidevariationsinfuelquality,whilestillachievingstrictairemissionrequirements.Low-gradefuelsthathavelargeashcontentandveryhighsulfurdonotnormallyfindacceptanceinpulverizedcoal(p.c.)units.ThesefuelsareburnedefficientlyinCFBsystems.However,ifthesulfurcontentislarge,thennecessarysorbenthastobeaddedtocaptureSO2insolidform.Forpersonaluseonlyinstudyandresearch;notforcommercialuseCFBboilersgeneratetwomajorwastestreams,flyashandbottomash,whichareamixtureoffuelash,unburnedcarbonresidues,andlimeparticlescoatedwithsulfatelayers.Theashpropertiesaresubstantiallydifferentfromthep.c.ashestypicallymarketedasASTMClassCandFflyashes.TheoperatingconditionsforCFBCunits,inadditiontothefuelandsorbentcharacteristics,directlycontributetothechemicalcharacteristicsoftheashes.CFBashesgenerallycontainahighercontentofcalciumasanoxideandasasulfate,butalowercontentofsilicaandaluminathanashesgeneratedfromp.c.boilers.Onenotableexceptionisashesresultingfromthefiringoflowsulfuranthracitesandbituminouscoals;theseby-productsarecomposedprimarilyoffuelashconstituents,sincesorbentdoesnotdominateashchemistry.Consequently,theutilizationoptionsforCFBashesaresomewhatmorediversethanp.c.ash,duetotheeffectofsorbentontheoverallashchemistry.Pressurizedfluidizedbedcombustion(PFBC)representsoneofthemostpromisingemergingCleanCoalTechnologies(CCT).CirculatingPFBCtechnologyisbeingdemonstratedatthepilot-scaleatFosterWheelerEnergiaOyinKarhula,Finland.WesternResearchInstitute(WRI)hascompletedathree-yearprojectundersponsorshipoftheElectricPowerResearchInstitute(EPRI),FosterWheelerEnergyInternational,Inc.,andtheU.S.DepartmentofEnergy(DOE)FederalEnergyTechnologyCenter(FETC)thataddressedashusemarketsandoptionsforPFBCtechnologies.FWsuppliedrepresentativeashsamplesfromtheKarhulaPCFBpilotcombustoroperationforthisstudy.TheoverallobjectivesofthisstudyweretodeterminethemarketpotentialandthetechnicalfeasibilityofusingPFBCashinhigh-volumeuseapplications.TheEnvironmentalProtectionAgency(EPA)madeafinalrulethateffectiveSeptember2,1993,fourlarge-volumefossilfuelcombustion(FFC)wastestreamsfromelectricutilitypowerplantsareexemptedfromRCRA(ResourceConservationandRecoveryActof1976)SubtitleCforhazardouswasteregulations(FederalRegister1993).Thewastestreamsincludeflyash,bottomash,boilerslags,andfluegasdesulfurization(FGD)sludge.Nevertheless,thefluidizedbedcombustion(FBC)wastestreamswerenotincludedinthisfinalregulatorydeterminationduetothelackofinformation.Sinceearly1990s,extensivestudieshavebeenconductedontheACFBandPCFBashes(Young,1996;ConnandSellakumar,1997,Conn,Wu,andSellakumar1997;Bland,1998).Inthispaper,areviewoftheACFBandPPCFBprocesses,keychangesintheby-productconstituents,andattendantdifferencesinthephysicalandchemicalpropertiesaredescribed.Inaddition,thecurrentandpotentialusesoftheby-productsareoutlined.ACFBANDPCFBPROCESSESInfluidizedbedcombustors,limestoneisaddedinthebedforsulfurcapture.ProbablesulfurcapturemechanismsintheACFBandPCFBcombustorshavebeensummarizedearlier(Koskinenetal.,1993).Numerousstudieshaveconfirmedthatatatmosphericconditions,thefirststepinthesulfurcaptureprocessisthecalcinationofCaCO3.CaCO3(s)→CaO(s)+CO2(g)(1)Thecalcinationreactionproceedssignificantlyfasterthanthenextstepthatisthesulfurcapturestep,calledthesulfationreaction.CaO(s)+SO2(g)+1/2O2(g)→CaSO4(s)(2)Underpressurizedfluidizedbedcombustionconditions,thehighpartialpressureofCO2thatexistsbyvirtueofthehighcombustorpressure,preventsthedecompositionofCaCO3.AthighO2partialpressures,thedesulfurizationreactioninpressurizedconditionsisviathe"direct"sulfationofCaCO3.CaCO3(s)+SO2(g)+1/2O2(g)→CaSO4(s)+CO2(g)(3)However,inthepresenceofsomecatalystsSO2(g)canbeconvertedtoSO3(g),andthefollowingreactionisalsopossible(Hajaligoletal.1988):CaCO3(s)+SO3(g)®CaSO4(s)+CO2(g)(3a)ThermaldecompositionofCaSO4innormalpressurizedfluidizedbedcombustionconditionsisnotprobablebecauseoflowtemperaturesandhighpressuresinthereactor.However,accordingtoLygnfeltandLeckner(1989)significantamountsofSO2maybereleasedfromthesorbentinthepressurizedfluidizedbedcombustionifconditionsbecomereducinginthereactor.Insummary,itcanbeconcludedthatunderPCFBconditions:-thesulfationofsorbentstakesplacebyadirectreactionbetweenCaCO3andSOx..-thesulfationrateincreaseswithtemperatureand-thetotalpressureinthecombustordoesnotlimitthesulfurcapturebythesorbent.-ThesurfacestructureoftheashparticlesfromthePCFBprocessislikelytobedifferentfromthatoftheashfromtheACFBprocess.CHARCTERIZATIONOFACFBASHChemicalProperties:KeyoxidesofinterestforashuseintypicalACFBbottomashandflyasharepresentedinTable1.Thechemicalcharacterizationtestingincludedmajorelementcomposition,aswellasphaseanalysis.ThereisageneraldecreaseinCaOandSO3withdecreasingsulfurcontentofthefuelburned.Fuelashcontributessilica,alumina,andcertainamountsofalkalis.TheflyashandthebedashwerealsoanalyzedbyX-raydiffraction(XRD)forphasecomposition.Thedataconfirmtheobservationthattheashesarecomposedprincipallyofanhydrite[CaSO4],lime[CaO],quartz[SiO2],andassociatedoxidesofiron,magnesium,anddehydroxylatedclaysoriginatingfromthefuelashcomponents.PhysicalProperties:Thegeneralphysicalpropertiesoftheasheswerealsodetermined,includingpouredandpackedbulkdensities,specificgravity,particlesizedistribution,andmoisture.Theflyashesallwererelativelyfinewithgreaterthan80%passinga200-meshscreen(74mm).Asaresult,theseashescanreadilybemadeintocement-typepasteswithoutfurthermilling.Thepouredbulkdensityoftheflyashesrangedfromabout540(lowSfuel)to916(highSfuel)kg/m3;thecompactedbulkdensityoftheflyasheswereslightlyhigherandrangedfrom840(lowS)to1167(highS)kg/m3.Thespecificgravityrangedfrom2.2(lowS)to2.7(highS)fortheflyashes.CHARACTERIZATIONOFPCFBASHThestudyofPFBCashuseoptionshasincludedtwodifferentashes:ashfromthecombustionoflow-sulfurPowderRiverBasinsubbituminouscoal(BlackThunder)withlimestonesorbentandthecombustionofhigh-sulfurIllinoisBasincoalwithalimestonesorbent.(Bland,1998).GeneralChemistry:Withtheexceptionofrelativelyhighmineralcarbon,thechemistryofthePCFBashesistypicalofashesfromACFBoflow-sulfurandhigh-sulfurcoalsusinglimestoneanddolomitesorbents.PhaseanalysesoftheashesbyX-raydiffractionshowthatthePCFBashesarecomposedprincipallyofanhydrite(CaSO4),calcite(CaCO3),coalashoxides,anddehydroxylatedclays.Thelackoflime(CaO)inthePFBCashesisdistinctlydifferentfromAFBCashes,whichcontainlargeamountsoflime.Asstatedearlier,inPFBCsystems,thepartialpressureofCO2favorsbothcalcinationandrecarbonization.Thisresultsinlowlimeandhighcarbonates(calcite)inpressurizedFBCash.KeyoxidesofinterestforashusearepresentedinTable1.Thelossonignition(LOI)iscomposedofthemoistureandtheorganiccarbon.TheLOIinthePFBCasheshasbeencorrectedformineralcarbon.Moisturesarelessthan0.1%andtheorganiccarboncontentsarelessthan2%.Thefreelime(CaO)contentofthePFBCasheswasdeterminedbyASTMC-25tobeintherangeof0.5to1.0%.ThemajorityofthelimeappearstostillbecarbonatedintheformofCaCO3.PhysicalProperties:Thegeneralphysicalpropertiesoftheasheswerealsodetermined,includingbulkdensities,specificgravity,andparticlesizedistribution.ThePCFBflyashesmeasuredpoured-bulkdensitiesof795to948kg/m3andspecificgravitiesof2.73to2.34forhighsulfurandlowsulfurfuelsrespectively.ThisisjustoppositeoftheACFBflyashcharacteristicsDISCUSSIONAshCharacteristics:LeachatecharacteristicsoftheashesweretestedaccordingtotheU.S.EPAToxicityCharacteristicsLeachingProcedure(TCLP)(EPACFRPart241).TheashleachatedatasubstantiatethatnoneoftheleachatesgeneratedfromtheACFBandPFBCashesexceededthe1976RCRAlimits.Assuch,theseasheswouldnotbeclassifiedashazardous.Ashesfromothercoal-firedpowersystemsarealreadycategorizedasnonhazardousandhavebeengivenanexclusionfromtheseRCRArequirements(Table2).AshUtilizationStudies:DiverseutilizationoptionshavebeenstudiedforACFBandPCFBcoalashes.Thepotentialapplicationsinclude:-constructionapplications:cementsubstitute,concreteblockproduction,brickproduction,soilstabilizer,roadbase/subbasematerials,structuralfillmaterials,andsyntheticaggregates;-agriculturalapplications:limingandsoilamendment;-wastestabilization:acidicwastestabilizerandsludgestabilizer.Thekeyfuelandsorbentproperties,whichcaninfluenceashcharacteristics,aresulfurcontent,ashcontent,andashcompositionincludingtheformofCa(CaCO3orCaO).Otherimportantfuelpropertiesinfluencingashcharacteristicsarethesizeandfriabilityofthefuelminerals.ThesepropertieswillimpactonhowthesemineralswillexittheCFBintheflyorbottomashstream,whichcanhaveasignificanteffectontheutilizationofthesestreams.ExtensiveliteratureisnowavailableontheACFBashuseoptionsbasedonthestudiessinceearly1980s.(Anthonyetal.1995,Kilgouretal,1991,Sunetal.1980,Tavoulareasetal.1987;Connetal.1997;Bland,1998;Bland,1999).DetailsonPCFBashusehasbeenreportedsince1993(Blandetal.1994;Bland,1998).Asummaryofthecurrentknow-howisgivenbelow.AshUseinConstructionApplications:ACFBandPCFBflyashescannotbeclassifiedasClassForC,becauseoflowFAS(ferricoxide,alumina,andsilica)andhighSO3content(Table1).EventhoughCFBflyashmaynotqualifyasaPortlandcementadmixture,itmayhavethepotentialforuseinconcreteblocks.Bottomandflyashcanbeusedasanaggregateandpozzolaninconcreteblocks.Thebottomashusedasanaggregatehasalowerunitweightthanmanynaturallyoccurringaggregates,thusreducingtheweightoftheblock.CFBflyashwithpropertiesofClassCandFcanbeusedasapartialreplacementforPortlandcementinsomeblockplants.Generally,thecarboncontentoftheflyashmustbelimitedtolessthan5%,sincesegregationcanoccurduringhandlingandresultinnonuniformblocks.ThefreelimeandsulfatecontentsofCFBashescanlimittheirutilizationinconcreteblockproduction.Freelimepresentinashwillformwater-solublecalciumhydroxide,resultinginweakeningoftheblockfromcontactwithmoisture.AswithPortlandcementconcrete,ettringitecanforminconcreteblocksduetohighashsulfatelevelsresultinginmechanicalweakeningoftheblock.ItispossiblethatCFBashmayreplacesomeClassCorFflyashorPortlandcementinmoremoderatestrengthblocks.Suchmaterialsmaynotbepreferredforheavyconstructionapplications,butmoreforresidentialuses(Connetal.1997).TestingofPCFBashhasindicatedthatPFBCash,whenmixedwithlowamountsoflime,developshighstrengths,suitableforsoilstabilizationapplicationsandsyntheticaggregateproduction.SyntheticaggregateproducedfromPFBCashiscapableofmeetingASTM/AASHTOspecificationsformanyconstructionapplications(Bland1998).Soil/MineSpoilAmendment:ThetechnicalfeasibilityofACFB/PFBCashasasoilamendmentwasexaminedforacidicproblemsoilsandspoilsencounteredinagriculturalandreclamationapplications.Theresultsofthetechnicalfeasibilitytestingindicatedthefollowing:·AshstreamsfromCFBboilersfiringlowsulfursemi-anthraciteandanthracitewastewouldnotbegoodcandidatesforagriculturallimingduetoverylowfreelime(andCaCO3equivalent)contents.Ontheotherhand,ashstreamsfromCFBboilersfiringbituminouscoalsmaybesuitableforliming,dependinguponhowcalciumispartitionedbetweentheflyashandbottomash.·PFBCflyasheswereeffectiveacidspoilandsodicspoilamendmentsthoughtheyhavelowCaOcontent.Inacomparisonwithag-lime,theflyashesreactedwiththeacidicspoilataslowerrateandthefinalpHofthetreatedmaterialwasslightlylower(i.e.,flyashtreated,pH≈7andtheag-limetreated≈8).·thegreenhousestudiesdemonstratedthatPFBCflyashamendedspoilsresultedinhigherplantproductivitythantheag-lime-amendedspoils.TheseresultspossiblyareduetopHandnutritionalissues,butrootpenetrationwasundoubtedlyafactor.CFBashstreamscanalsobeusedtostabilizewastestreamsfromavarietyofprocessingoperations.Thisstabilizationincludessolidificationandfixationofsludgematerialsforlandfilling,neutralizationofacidicwastes,andmunicipalsludgewastesludge.Foreachoftheseapplications,thesuitabilityofCFBashisenhancedbyitsfreelimecontent.CONCLUSIONIn-houseandliteraturedatashowthatashstreamsfromCFBboilersfiringdiversefuelshavethepotentialforuseinoneormoreapplications.FWhasstudiedtheACFBbottomashandflyashcharacteristicsfrombothanenvironmentalimpactandby-productutilizationstandpoint.First,theriskscreeningcriteriaandexposureanalysisresultsindicatethattheseCFBwastesareascleanorbetterthanthosegeneratedfromconventionalcombustorssuchasp.c.boilers.Asaresult,CFBby-productscanbeusedinvariousapplicationswithoutimpactingtheenvironment.TheexactutilizationoptionsforACFBby-productswilldependprimarilyonthetypeoffuelbeingfired,andtoalesserextentthetypeofsorbentutilizedforsulfurcapture.ThePCFBashdiffersfromtheACFBintheuncalcinedCaCO3intheby-product.AswithACFBashes,thereisasignificantmarketpotentialforPFBCashintheconstructionandsoilamendmentindustries.Inparticular,PFBCashrepresentsatechnicallyviablematerialforuseinthesecurrentlyestablishedapplicationsforconventionalcoalcombustionashes.ItispossibletomodifythehydrationreactionchemistryofthePFBCashesthroughsuchprocessesaslimeenhancementtoproducethegeotechnicalpropertiesrequiredforconstructionapplications.Asaresult,PFBCashshouldbeviewedasavaluableresource,andcommercialopportunitiesforthesematerialsshouldbeexploredforfuturePFBCinstallations.REFERENCESAnthony,E.J.,Iribane,A.P.,andIribane,J.V.,Proc.ofthe13thIntl.Conf.onFluidizedBedCombustion,Orlando,FL,(1995),Vol.1,pp.523-533.Bland,A.E.USDOEContractDE-FC21-93MC30126,FinalReport(WesternResearchInstituteReport–WRI-98-R017),June,(1998).Bland,A.E.,Proc.,1998AdvancedCoal-BasedPowerandEnvironmentalSystems‘98Conference,USDepartmentofEnergy,Morgantown,WV,(1998).Bland,A.E.,Proc.ofthe15thIntl.Conf.onFluidizedBedCombustion,Savannah,GA,(1999).Conn,R.E.,andSellakumar,K.M.,Proc.ofthe14thIntl.Conf.onFluidizedBedCombustion,Vancouver,Canada,(1997),pp.507-518Conn,R.E.,Wu,S.,andSellakumar,K.M.,1997PittsburghCoalConf.,Taiyuan,China(1997)Conn,R.E.,Sellakumar,K.M.andBland,A.E.,Proc.ofthe15thIntl.Conf.onFluidizedBedCombustion,Savannah,GA,(1999).FederalRegister,PartV,UnitedStatesEnvironmentalProtectionAgency,40CFRPart261,Vol.58,No.151,August9,1993.Hajaligol,M.R.,Longwell,P.J.,Sarofim,A.F,Ind.Eng.Chem.Res.27,(1988),pp.2203-2210..Kilgour,C.L.,andMcGowan,K.I.,ElectricPowerResearchCenter,IowaStateUniversity,FinalReport,October(1991).Koskinen,J.,Lehtonen,P.,andSellakumar,K.M.,Proc.ofthe13thIntl.Conf.onFluidizedBedCombustion,Orlando,FL,(1995),pp.369-378Lygnfelt,A.,andLeckner,B.,Proc.,10thInternationalConferenceonFluidizedBedCombustion,Manaker,A.,ed.,ASME,NewYork,(1989),pp.675-684Sun,C.C.,andPeterson,C.H.,Proc.SixthIntl.Conf.onFluidizedBedCombustion,Philadelphia,PA,(1980),Vol.3,pp.900-912.Tavoulareas,S.,Howe,W.,Golden,D.,andEklund,G.,Proc.ofthe9thIntl.Conf.onFluidizedBedCombustion,(1987),Vol.2,pp.916-926.Young,L.,FifthIntl.Conf.onCirculatingFluidizedBeds,Beijing,(1996),Pr5

循环流化床锅炉及尘埃andR.Conn美国，新泽西州07039，利文斯顿，桃树路连山道12号，福斯特惠勒开发公司摘要：循环流化床技术的出现为各类型的燃料无环境污染的使用提供了途径。由于在不久的将来，增压循环流化床（PCFB）将拥有潜在的商业应用价值，所以有必要研究一下增压循环流化床（PCFB）和常压循环流化床（ACFB）产生的固体副产物的特性的相似和差异。与常压循环流化床残留物相似，增压循环流化床的残留物的主要部分来自：—煤炭的燃烧生成沉积物的无机成分（铝，铁，硅），—吸附剂派生物（来自石灰石的钙，或者（如果用白云石）钙和镁），—燃烧过程中，被吸附剂捕获的从煤中散发的硫分。然而，在同一个燃烧装置中不同残留物的浓度存在极大的变数，这取决于煤种和运行工况。通常，在相同煤种和脱硫率情况下，与常压循环流化床相比，增压循环流化床装置排放的残留物中钙的含量较低，而煤炭派生的无机成分含量较高。这是因为增压循环流化床需要较少的吸附剂。此外，来自这两个系统的残留物中吸附剂派生物含量的不同取决于常压和增压下的硫化机理的不同。这次研究所用炉灰样取自已经商业运行的常压循环流化床锅炉发电厂和在Karhula的以试点规模运行的福斯特惠勒10MWth增压循环流化床。在这篇论文中，煤灰特性以及增压循环流化床和常压循化流化床生成的炉灰哪个有更好的应用，都做了说明。引言循环流化床是一种已被认可的极具前景的新型燃烧技术，它具有燃料适应范围广的优点，可以燃用的煤种很广，也可以燃用其他石化燃料，对燃料质量的适应范围广，且满足了严格的烟气排放要求。含较多灰分和硫分的低档煤通常不能在煤粉炉中使用。这些煤在循环流化床中可以高效的燃烧，但是如果硫分含量过大，那么就要添加吸附剂来捕获二氧化硫。循环流化床锅炉产生两种废物气流，飞灰和底灰，这是煤灰，未燃尽的碳残留物和涂有硫酸层石灰石颗粒的混合物。这些炉灰与通常国际材料试验协会规定的C级和F级市场销售的煤粉炉的炉灰不同。循环流化床装置的运行状况，除了燃料和吸附剂的特性，而且直接决定了炉灰的化学特性。与煤粉炉相比，循环流化床炉灰一般含有较高的氧化钙和硫酸钙，但是二氧化硅和氧化铝的含量较小。一个值得注意的例外是燃烧低硫分的无烟煤和烟煤时，这些副产品主要是煤灰成分，这是由于吸附剂在化学反应中不起主导作用。因此，循环流化床锅炉炉灰的利用方式比煤粉炉炉灰有更多的方式，这是由于吸附剂在整个炉灰的化学反应中的影响。增压流化床燃烧是最有前途的新型清洁煤燃烧技术之一。增压循环流化床技术正在芬兰karhula的福斯特惠勒能源oy公司以试点规模运行。在电力研究协会（EPRI），福斯特惠勒能源国际公司和美国能源部（DOE）的联邦能源技术中心（FETC）的赞助下，西部研究所（WRI）已完成了解决炉炉灰利用方式和增压流化床技术的为期三年的项目。在Karhula的FW公司的增压循环流化床试点燃烧室提供了本次研究的炉灰样本，这项研究的总体目标是确定高容量增压流化床生成的炉灰使用的市场潜力和技术上的可行性。环境保护署（EPA）制定了最终的条例，1993年9月2日生效，由电力公司发电厂排放的四大废物流不属于RCRA（资源保护和回收法）小标题C项的危险废物的规定（联邦纪事：1993）。废物流包括飞灰、底灰、锅炉炉渣和烟气脱硫（FGD）的污泥。然而，由于缺乏有效信息，流化床（FBC）的废物流未有纳入最后的监管。20世纪90年代以来，对常压循环流化床和增压循环流化床产生的炉灰进行了深入的研究（Young，1996年，Conn和Sellakumar，1997年，Conn，Wu，Sellakumar1997年，Bland，1998年）。本文对ACFB和PPCFB的审查过程，副产物成分的关键变化以及随之而来的在物理和化学性质上的差异做了详细的描述，此外，对副产物现有的和潜在的用途做了概述。ACFB和PCFB进程在流化床燃烧室中，添加石灰石起到固硫的作用。ACFB和PCFB在燃烧室可行的固硫的措施已经被总结（Koskinenetal，1993）。无数的研究已经证实在常压下，固硫过程中的第一步是碳酸钙煅烧。CaCO3(s)CaO(s)+CO2(g)（1）焙烧反应进行下一步就是固硫步骤成为硫酸化反应，速度很快。CaO(s)+SO2(g)+1/2O2(g)CaSO4(s)（2）在增压流化床燃烧条件下，燃烧室高压下，CO2高分压抑制CaCO3的分解。在O2高分压下，在加压装置中，脱硫反应是通过“直接”碳酸钙硫酸化。CaCO3(s)+SO2(g)+1/2O2(g)CaSO4(s)+CO2(g)(3)然而，在一些催化剂的作用下，二氧化硫（G）可以转化为三氧化硫（G），下面的反应也可能发生（Hajaligol等1988）：CaCO3(s)+SO3(g)CaSO4(s)+CO2(g)(3a)在正常的增压流化床燃烧条件下，由于炉内低温高压，所以硫酸钙是不可能分解。然而，根据Lygnfelt和Leckner（1989）的研究，如果增压流化床内条件变小，大量的二氧化硫可能从吸附剂释放出来。综上所述，在增压循环流化床条件下可以得出以下结论：—吸附剂硫酸化通过碳酸钙和硫之间直接反应而发生。—固硫率随着温度而增加。—燃烧室整个压力对吸附剂固硫没有限制。—PCFB过程中产生的灰颗粒表面结构可能与ACFB过程产生的不同。ACFB炉灰的特性化学性质：ACFB的底灰和飞灰中的重要氧化物列于表1.化学特性测试中包含的主要元素组成，以及相应分析。随着燃烧燃料含硫量的减小，氧化钙和三氧化硫普遍下降。煤灰有助于二氧化硅，氧化铝，和一定数额的碱的生成。煤灰和飞灰的组成成分可以用X射线衍射仪（XRD）分析。分析数据确认一下描述：这些炉灰主要有硬石膏（CaSO4），石灰（CaO），石英（SiO2），铁、镁相关的氧化物以及来自煤灰成分的无机粘土相关氧化物。物理性质：炉灰的一般物理性质也决定了它的浇筑和压缩的容重、比重、粒度分布和水分含量。飞灰都比较精细，超过80%的飞灰颗粒可以通过200目筛（74毫米），因此这些灰不需要进一步的研磨，可以很容易的制成水泥糊。那些浇筑炉灰的容重范围大约为540kg∕m3（低硫分燃油）到916kg∕m3（高硫分燃油）。压缩的炉灰的容重比较高，范围约为840kg∕m3（低硫分）到1167kg∕m3（高硫分）。飞灰的比重从2.2（低硫分）到2.7（高硫分）不等。PCFB炉灰的特性增压流化床炉灰利用方式的研究包括两种不同的灰：粉河盆地的底硫分的亚烟煤（黑雷）与石灰石脱硫剂的燃烧产物和伊利诺伊盆地的高硫分煤与石灰石脱硫剂的燃烧的产物（布兰德，1998年）。化学性质：除了相当高的矿物质碳，PCFB炉灰的化学性质与ACFB使用石灰石和白云石作为脱硫剂燃烧高硫分和低硫分煤时产生的炉灰没有区别。通过X射线的衍射得出的该炉灰相分析显示：PCFB炉灰主要有石膏（CaSO4），方解石（CaCO3）

，煤灰氧化物和无机粘土做成。石灰含量小时PFBC灰与AFBC灰的最大不同，AFBC炉灰包含了大量的石灰。如前所述，在增压流化床中，二氧化碳分压有利于煅烧和再碳化。增压流化床在低石灰和高碳酸盐下的产生炉灰的结果和有用的重要氧化物部分列于表1.烧失量（LOI）由水分和有机碳组成。PFBC的烧失量，由矿物质碳弥补。水分小于0.1%，有机碳含量小于2%。PFBC炉灰的游离态石灰（CaO）含量由ASTMC-25测定，在0.5%到1%范围内，大部分石灰石似乎仍以碳酸钙的形式存在。物理性质：炉灰的一般物理性质决定了它的容重，比重和粒度分布。对于高硫分和低硫分来说，PCFB飞灰测量浇筑容重从795kg∕m3到948kg∕m3，比重从2.73到2.34。这与ACFB炉灰的性质相反。讨论炉灰的特性：炉灰渗滤液特性根据美国EPA毒性特征浸出程序（TCLP）（EPACFR第241）进行了测试。炉灰渗滤液的数据证实，没有ACFB和PFBC炉灰渗滤液超过1976年的RCRA的限制。因此，这些炉灰将不会被列为危险物。从其他发电系统排出的炉灰已被归类为无害，并且已从RCRA限制中排出。炉灰综合利用的研究：ACFB和PCFB燃烧煤炭生成的炉灰的多元化利用方案已经进行了深入的研究。—建筑应用：替代水泥，混凝土砌块生产，砖块生产，土壤固定，路基∕底基层材料，结构的填充材料，合成聚合物；—农业应用：石灰和土壤改良剂；—垃圾的稳定：酸性废物稳定和污泥稳定。燃料和吸附剂的重要属性，如硫含量，灰分，灰成分，包括Ca（CaCO3和CaO）存在形式都会影响炉灰的特性，燃料其他重要的属性如燃料矿物的大小和脆性也会影响炉灰的性质。这些属性将影响炉灰如何通过飞灰流和底灰流排出循环流化床，且对气流的利用率产生很大的影响。上世纪80年代初以来的研究为ACFB炉灰的利用方式提供了广泛的文献参考。（Anthony等，1995年，Kilgour等，1991年，Sun等，1980年，Tavoulareas等，1987年；Conn等，1997年；Bland，1998年，Bland，1999年）。关于PCFB炉灰的利用方式的详细报告已从1993年就开始发表了（Bland等，1994年；Bland，1998年）。下面给出了一些使用方法的总结。炉灰在建筑方面的应用：ACFB和PCFB飞灰不能被归类为F和C级，因为FAS（氧化铁，氧化铝和二氧化硅）含量低和三氧化硫含量高（表1）。甚至CFB飞灰没有资格最为波特兰水泥外加剂，它也许可以应用于混凝土块中。底灰和飞灰可作为聚合材料用于混凝土块。低灰作为聚合材料比其他自然聚合材料较轻，从而降低了混凝土块的重量。循环流化床飞灰具有C和F级的性质，可以用来替代波特兰水泥块的块状部分。一般来说，飞灰的含碳量必须低于5%，否则可能使水泥块产生不均性的后果。CFB炉灰中游离石灰和硫酸将限制其在混凝土方面的应用。灰中游离态的石灰将形成溶于水的氢氧化钙，从而削弱水泥块与水分的接触。若灰中硫分高，与波特兰水泥混合，将在混凝土块中产生钙矾石，导致块的机械强度的降低。循环流化床锅炉炉灰替代一些C和F级炉灰或者中等强度的混凝土砌块中的波特兰水泥，这是有可能的。这些材料不是重型建筑材料的首选，多为住宅建筑用材（Conn，1997年）。PCFB炉灰的测试表明：增压流化床炉灰与低量石灰混合，有助更好发挥它的优势，适用于土壤固定和提高综合产量。由PFBC灰合成的材料在许多建筑应用中满足ASTM∕AASHTO规范（Bland，1998）。土壤∕矿弃渣改良应用：在填海工程和农业酸性土壤问题上，ACFB∕PFBC炉灰作为土壤改良剂的技术可行性进行了测试。结果如下几点：—燃用低硫分半无烟煤和无烟煤废物的循环流化床排放的炉灰流不能作为农业石灰，因游离态的石灰含量低。另一方面燃用烟煤的流化床排放的炉灰流能否作为农用石灰，取决于飞灰和底灰中的该是怎么样分离的。—虽然PFBC飞灰的CaO含量较低，但可以有效的改善土壤酸性。与AG石灰相比，飞灰以较慢的速度中和酸性，最终处理结果PH稍低。（即飞灰处理PH≈7；AG石灰处理，PH≈8）—温室研究表明：增压流化床飞灰改良土壤后，植物产量比AG石灰改良后的高，这些结果可能与PH和营养有关，但根系的渗透无疑也是个因素。循环流化床锅炉炉灰也可用于固化各种工业废弃物，如固化填埋的污泥，中和酸性废物和城市排放废物。对于这方面的应用，循环流化床炉灰的应用性的提