CIBO Emissions Control ConferenceBiomass: FueloftheFuture?ass ue o t e utu ePresented by Tom Sarkus200909-GASIF215-1 – UAF Coal-Based Region StudiesAugust 5,Rev 1 CIBOBUZZ Words For TodayBUZZWordsForTodayBIOMASSBLENDSCO-FIRING209-GASIF215-2 – UAF Coal-Based Region StudiesThank You!Many of the slides and information presented here are courtesy ofDr. David A. TillmanandDao N.B. DuongofFoster Wheeler North AmericaOriginal presentation and papers titled“Fuel Blending for Bituminous Coal Boilers: Some Fuel Effects”“Co-Firing – Basic Issues and Concerns”“Fuel Selection for Cofiring Biomass in Pulverized Coal and CycloneFried Boiler”309-GASIF215-3 – UAF Coal-Based Region StudiesReasons for Fuel Blending•Supply– Original coal mine worked out;supplsecurityy y•Economics–Reduce coal costs &powercosts; tax credits•Environmental–Use cleaner burning(low sulfur, low nitrogen, low ash) coal•Regulatory– Thou will do so409-GASIF215-4 – UAF Coal-Based Region StudiesTypical Fuel Blends•Common Current blendsBituminous coal/bituminous coal–Bituminouscoal/bituminouscoal– Gob/bituminous coal–Bituminous coal/tire chips– Bituminous coal/petroleum coke–Bituminous coal/Powder River Basin [PRB] coalPRB l/li it–PRBcoal/lignite•Common future blends–Bituminouscoal/biomassous coa /b o ass–PRB coal/biomass–Waste coal/biomass509-GASIF215-5 – UAF Coal-Based Region StudiesUnique Performance Parameters for Coalsand Biomass FuelsandBiomassFuelsParameter CentralAppalachianIllinoisBasinPowder RiverBasinLignite WoodWasteSwitchgrassHHV Btu/lb A R12 11410 3348 9437 6135 0287 002HHV,Btu/lbA.R.,(55lb/cf)10,3348,9437,6135,028(18lb/cf)7,002(5lb/cf)lb/106Btu ofFuel83 97 112 131 199 143Fe2O3/CaO 3.63 3.04 0.26 0.54 0.03 0.36lb Cl/mmBtu 0.10 0.29 0.01 0.01 0.03 0.26Lb(NaO+KaO/106Btu0.38 0.28 0.11 0.13 0.49 1.41Lb S/106Btu 0.88 3.14 0.26 1.10 0.14 0.24lb H2O/106Btu 5.91 5.79 28.89 35.12 83.53 14.05lb ash/106Btu 9.51 10.29 5.65 12.05 4.59 11.55lb fuel N/106Btu 1.11 1.05 0.75 0.77 1.19 0.99VM/FC Ratio 0.62 0.73 0.84 1.08 6.05 5.35Cl/S molar ratio0 120 100 050 010 211 17609-GASIF215-6 – UAF Coal-Based Region StudiesCl/Smolarratio0.120.100.050.010.211.17Guiding Principle:Fuels are unique.Bl di t f lBlendingtwo or morefuelstogether creates a new &unique fuel.709-GASIF215-7 – UAF Coal-Based Region StudiesUnique Blends of Central Appalachian Coaland WoodandWoodParameter 0% Wood Co-fired 5% Wood Co-fired(Heat Input Basis)10% Wood Co-fired(Heat Input Basis)20% Wood Co-fired(Heat Input Basis)Mass % of Wood 0% 11.25% 21.12% 37.59%HHV, Btu/lb 12,114 11,316 10,617 9,450Base/Acid 0.20 0.22 0.24 0.29Fe2O3/CaO 3.63 2.43 1.78 1.10lb Cl/mmBtu 0.10 0.10 0.09 0.08lb(NaO+ 0.38 0.39 0.39 0.41KaO/106Btulb SO2/106Btu 0.88 0.85 0.81 0.73lb H2O/106Btu 5.91 9.79 13.67 21.43lb ash/106Btu 9.51 9.26 9.02 8.53lb fuel N/106Btu 1.11 1.11 1.11 1.12VM/FC Ratio 0.62 0.73 0.84 1.09809-GASIF215-8 – UAF Coal-Based Region StudiesCl/S molar ratio 0.12 0.12 0.13 0.13Second Guiding PrincipleEach blend is unique and mustbe e al ated on its o n termsbeevaluatedonitsownterms.There are blending principles,however, that can be used toevaluate blending.909-GASIF215-9 – UAF Coal-Based Region Studiesevaluateblending.Locations for Blending•At an off-site blending facility•In the coal yard (blending here is measuredand controlled blending, not bucketandcontrolledblending,notbucketblending)•In coal pipes or chutes leading from the millsto the burners or boiler(this is verydifficult)y)•In the boiler1009-GASIF215-10 – UAF Coal-Based Region StudiesBiomass Handling - The 10 Keys•Fuel Handling not glamorous,but oh so important•Keep transport velocitiesabove flame speed of biomassbutohsoimportant•Keep biomass separate in coalyard•Keep biomass away from coalaboveflamespeedofbiomass(120 ft/sec)•When biomass is moving, keepit moving•Keepbiomassawayfromcoalbunkers and silos. It needs itsown silos•Don’t use coal prep equipmentitmoving•Do not mix biomass types in atransportation system•Particle sizing is important;•Don tusecoalprepequipmentfor biomass which is fibrous•If firing with pneumatictransport recognize biomass•Particlesizingisimportant;biomass does not need to be asfine as coal•Firing method is important;transport,recognizebiomassgenerally equals pluggage•Firingmethodisimportant;flame structure within the boiler& NOx control1109-GASIF215-11 – UAF Coal-Based Region StudiesCombustion Impacts:e.g., Bituminous Coal & PRB Coal•Some blends are well knownsignificant body of experienceSomeblendsarewellknown–significantbodyofexperience– Significant differences based on bituminous coal (e.g., CentralAppalachian vs. Illinois Basin)M j l t diff i l d i t lf t t–Major coalpropertydifferencesinclude: moisture, sulfur content,nitrogen content, chlorine content, ash content– Some additional major differences based on: coal reactivity, ashti it l h h i t ( ti l l F C K N )reactivity, coalashchemistry(particularlyFe,Ca,K,Na)• Blends do not behave as the weighted average of the fuels. Inparticular, reactivity and ash chemistry are influenced by subtleties1209-GASIF215-12 – UAF Coal-Based Region StudiesCapacity Impacts of Blends•Blend impacts on capacity–Increasing or reducing the effective Btu/lb & Btu/ft3of thefuel fed to the boilerfuelfedtotheboiler–Increasing or decreasing the volume of gaseouscombustion products (e.g., from moisture) past thecapability of the forced draft or induced draft fanscapabilityoftheforceddraftorinduceddraftfans•Blends that can increase capacity–Bituminous coal & petroleum cokeBlends that can decrease capacity•Blendsthatcandecreasecapacity–Bituminous coal & low rank coals [e.g., high percentages ofPRB coal]Bi i l & i ifi f bi–Bituminous coal&significant percentages ofbiomass[>20%]–In waste coal operation biomass may not increasing ord i th t t1309-GASIF215-13 – UAF Coal-Based Region Studiesreducingthe outputFlame Profiles of Blends•Some impacts of bituminouscoal/biomass blends [10-20%•Some impacts of bituminouscoal/PRB blends [>50% PRB]coal/biomassblends[1020%biomass]– More rapid ignition of thefuel masscoal/PRBblends[ 50%PRB]– More coal in boiler– Flame filled boilerMore gaseous combustionfuelmass– More gaseous combustionproducts – watch fans•Impacts of coal/pet coke blends–Moregaseouscombustionproducts – can push fancapacity limits•Impactsofcoal/petcokeblends– Less fuel in boiler– Slower combustionM bi h–ore combustion as charoxidation– Less gaseous combustiond t1409-GASIF215-14 – UAF Coal-Based Region StudiesproductsEfficiency Impacts•Blends have differing efficiency impacts; look forBt /lb & Bt /ft3f bl d–Btu/lb&Btu/ft3ofblend– Moisture content of blendAsh content of blend–Ashcontentofblend– Oxygen content of blend–Fixed carbon/volatile matter ratio of blend[can impactpunburned carbon]– If blending biomass in the boiler [separate injection],thi i th i h t it t t d tthis raisesthe airheater exittemperature andputsambient air in boiler; also an efficiency impact1509-GASIF215-15 – UAF Coal-Based Region StudiesDeposition Considerations• Some blends increase alkali & alkali earth elements – causeincreased depositionincreaseddeposition– Low rank coal & biomass blends [particularly blends withswitchgrass, corn stover, or other agricultural crops]•Some blends can decrease deposition by decreasing ash contentSomeblendscandecreasedepositionbydecreasingashcontentdramatically– Petroleum coke & woody biomass blends with low ash woodfuels• Some Issues of concern– Increased quantity of calcium fed to boiler (lb/hr)R fl i h i ll i f l k l–Reflective ashin waterwallsectionfromlow rankcoals– Fe2O3/CaO ratio; interaction between iron oxide (bituminouscoal) and calcium oxide (low rank coal or biomass)1609-GASIF215-16 – UAF Coal-Based Region StudiesCorrosion Considerations•Some key considerations–Chlorine in some•Some potentially problematiccombinationsChlorineinsomebituminous coals (e.g.,Illinois Basin, CentralAppalachian)combinations– Chlorine with alkali metals(particularly in the absenceof sulfur)– Alkali metals and earthelements in low rank coalsand biomassofsulfur)– Alkali metals withvanadium (formation ofdt )andbiomass– Vanadium in petroleumcoke–Low NOFiringvanadates)– Firing method plays a rolein thisissue–LowNOxFiring– CFB limestone will absorbsome of the Chlorines ssue1709-GASIF215-17 – UAF Coal-Based Region StudiesIndustry’s view:ThatSoundsGreat......But1809-GASIF215-18 – UAF Coal-Based Region StudiesCast of the"Buck Rogers in the 25th Century" Radio ProgramygLeft to Right: Curtis Arnall (wearing gravity-defying inertron), ElaineMelchior, William Shelley, Edgar Stehli (holding cybro-destructor ray),Adele Ronson.1909-GASIF215-19 – UAF Coal-Based Region StudiesBiomass - The 3 Summary Points•Higher mass fuel flows from very high mass percentage ofbiomass blend–20% biomass > 28% increase fuel flow > decrease in heatingvalue of blend•20% Biomass– > HHV decreases, fuel flow increases > Volatility increases >flame or heat release moves higher in furnace > Affects heattransfer > causes unburned carbon•Slagging & fouling may Increase at/in high temperature areas– As Base/Acid ratio > 0.2 to 0.3 > indicates possible problems–Na2O and K2> increase over 0.4 > possible slagging conditions– Fe2O3/CaO > fluxing ratio > moves into difficult area2009-GASIF215-20 – UAF Coal-Based Region StudiesConclusions-1•Blending is becoming increasingly common & willBlendingisbecomingincreasinglycommon,&willbe more so in the future•Blends will involve more low rank coals, waste fuels,& “green” fuels•Each blending application is uniqueBl d i t b dd d i i th•Blendissues mustbe addressedrecognizingthesubtleties of fuels and the interactions betweencomponents; blends do not behave as the weightedaverage of components2109-GASIF215-21 – UAF Coal-Based Region StudiesConclusions-2•Blend selection must take into account– Fuels available [physically, economically; e.g., Is thebiomass wood? Is pet coke available?]biomasswood?Ispetcokeavailable?]– Firing systems employed [CFB, wall-fired PC, t-firedPC, cyclone]– Needs of the station [capacity, efficiency, emissions]– Needs of the utility [green power & RPS, cost ofpower productionpowerproduction2209-GASIF215-22 – UAF Coal-Based Region StudiesConclusions-3•Each blend is uniqueEachblendisunique–You must proceed cautiouslywhen co-firingblends with your coal, waste coals & biomassRemember the 10 Keys–Rememberthe10Keys–Remember the 3 Summary Points2309-GASIF215-23 – UAF Coal-Based Region StudiesNETL Recommendation and CautionNETLRecommendationandCaution•For over 13 years, NETL has recommended with acautionary note the following when cofiring withcautionarynotethefollowingwhenco-firingwithCoal:– Biomass or other co-firing materials should be limitedto a range of 7% to 10 % by weight to reduce oreliminate operation problemseliminateoperationproblems–The capital cost of the receiving storing & preparingThecapitalcostofthereceiving,storing&preparing,and injection of opportunity fuel like biomass adds 7%to 10% to the capital costof a new power plant2409-GASIF215-24 – UAF Coal-Based Region Studies2509-GASIF215-25 – UAF Coal-Based Region StudiesContactThomas A. SarkusOffice of Major DemonstrationsOfficeofMajorDemonstrationsU.S. Department of EnergyNational Energy Technology Laboratory626 Cochrans Mill RoadP.O. Box 10940P.O.Box10940Pittsburgh, PA 15236-0940Office Phone: 412-386-5981Cell: 412-215-0339E-mail: Thomas.Sarkus@NETL.DOE.GOV2609-GASIF215-26 – UAF Coal-Based Region StudiesDisclaimerThis presentation was prepared as an account of work sponsored by an agency ofth U it d St t G t N ith th U it d St t G ttheUnited StatesGovernment.NeithertheUnited StatesGovernmentnoranyagency thereof, nor any of their employees, makes any warranty, express orimplied, or assumes any legal liability or responsibility for the accuracy,completeness or usefulness of any information apparatus product or processcompleteness,or usefulness of any information,apparatus,product,or processdisclosed, or represents that its use would not infringe privately owned rights.Reference therein to any specific commercial product, process, or service by tradename trademark manufacturer or otherwise does not necessarily constitute orname,trademark,manufacturer,or otherwise does not necessarily constitute orimply its endorsement, recommendation, or favoring by the United StatesGovernment or any agency thereof. The views and opinions of authors expressedtherein do not necessarilystate or reflect those of the United States Government orany agency thereof.2709-GASIF215-27 – UAF Coal-Based Region Studies