Ammonia - Wpca.info

Ammonia Supply Systemsfor SCRWPCA/Duke NOx SeminarJune 7, 2005Dr. Norman C. Foster

Why is Ammonia Required?• Ammonia (NH 3 ) is the ReducingAgent for NOx• 2 NH 3 + 2 NOx + ½O 22 N 2 + 3 H 2 OCopyright 2005 Chemithon Enterprises

N0 x Control Using AmmoniaCopyright 2005 Chemithon Enterprises

NH 3 Injection System ExampleCopyright 2005 Chemithon Enterprises

Typical Ammonia Requirements• 100‐5000 lb/h of AmmoniaCopyright 2005 Chemithon Enterprises

Sources of Ammonia• Anhydrous Ammonia• Aqueous Ammonia• UreaCopyright 2005 Chemithon Enterprises

Anhydrous Ammonia Properties• Molecular Weight ‐ 17.03• Vapor is 40% lighter than air• Flammable within narrow range 16‐25% in air• High heat of vaporization• Used as refrigerant• Approximately 588 btu/lb NH 3Copyright 2005 Chemithon Enterprises

Characteristics of AnhydrousAmmonia• Liquid when Compressed or Cooled• Stored as a Liquid under pressure• 1 Ft 3 of Liquid produces 865 Ft 3 of100% pure NH3 Gas• 1 Ft 3 of Liquid must be diluted with2,900,000 Ft3 air to reduceconcentration below 300 ppmCopyright 2005 Chemithon Enterprises

Anhydrous Ammonia VaporPressure350300250PSIG200150100500-50 0 50 100 150TEMPERATURE °F

Effect of Pressure• When liquid anhydrous NH 3 isreleased from storage pressure it cools• A drop from 200 psig (100 o F) toatmospheric pressure cools ammoniato –28 o F.Copyright 2005 Chemithon Enterprises

Anhydrous Ammonia Hazards• EPA Regulated Toxic Substance• 40 CFR Parts 9 and 68• Requires storage at 250 psig orRefrigeration• OSHA poisonous gas list• Hazards in Transportation and Storage• Single tanker truck spill ‐ 20 acre lethalareaCopyright 2005 Chemithon Enterprises

Anhydrous Ammonia RegulatoryRequirements• Transport, Handling & Incident Reporting: 49CFR 171‐180• Protection of Employees: 29CFR 1910, OSHA & DOL• Incident Reporting: 49 CFR 1904• Environmental Releases: 40 CFR 1‐799, FWPCA 1972,CWA 1977, CWA 1978, TSCA 1976,CERCLA 1980, SARA 1986• Emergency Planning and Community Right to Know:EPCRA 1986• Storage Tanks & Vessels: ANSI K61.1, ASME SEC VIII, Div 1• Process Piping: ANSI B31.3Copyright 2005 Chemithon Enterprises

Ammonia Exposure LimitsLeast perceptible odorReadily detectable odorNo health impairment for prolonged exposureGeneral discomfort; no lasting health effect for shortexposureSevere irritation; no lasting health effect for shortexposureDangerous less than ½ hour exposure may be fatalRapidly fatalImmediately fatal5 ppm20 – 50 ppm50 – 100 ppm150-200 ppm400 – 700 ppm2000- 3000 ppm5000- 10000 ppmOver – 10000 ppmFrom “Anhydrous Ammonia – Pamphlet G-2 Seventh Edition, Compressed GasInstitute

Uncontrolled Ammonia Releases• Ammonia Liquid refrigerates and formslethal fog of Water/NH3• Typical Water/NH 3 Cloud is white butmay be invisible• Water/NH 3 Clouds Move Unpredictablywith Air Movement• Water/NH 3 Clouds are heavier than airCopyright 2005 Chemithon Enterprises

Responding to an NH3 Release• Get out of the Area• Notify Emergency Response Staff• Isolate Ammonia Supply• Fog area with water sprayCopyright 2005 Chemithon Enterprises

Anhydrous Ammonia SystemAmmoniaUn-LoadingAmmoniaStorageAmmoniaPumpingAmmoniaVaporizationAmmoniaDilutionAmmoniaInjectionSafety Spray SystemCopyright 2005 Chemithon Enterprises

Anhydrous Ammonia SystemProcess• Ammonia is received by Tank Truck• Unloaded using Unloading Bulkhead and• Unloading Compressor System to Storage• Ammonia is pumped or flows by pressure from• storage to the vaporizers• The operating vaporizer evaporates ammonia• Ammonia vapor is piped to NH 3metering/Dilution Air• Skids• Ammonia is metered based on demand from SCR• Ammonia is metered into air and supplied to theAmmonia Injection Grid just upstream of the SCR.Copyright 2005 Chemithon Enterprises

Anhydrous NH3 System UnitOperations• Safety Systems• N 2 Supply System• Unloading Bulkhead• Unloading Compressor System (optional)• Ammonia Storage Tanks• Ammonia Pumping System• Ammonia Vaporizers• Ammonia Metering and Dilution Air Systems• Plant / Instrument Air Supply System• Control SystemCopyright 2005 Chemithon Enterprises

Anhydrous Ammonia SafetySystemsNH 3Sensor/Fog Water Areas•NH 3Storage Tank Area•Equipment Room•Unloading Area•Ammonia Metering Dilution Air Skids (3)Safety Equipment•Emergency Stops (E-Stops)•Safety Shower Eyewash Stations•NH 3Sensors•Local Alarm Panels w/ Flashing Beacon & Horn•Fog Water SystemsCopyright 2005 Chemithon Enterprises

Emergency Spray SystemCopyright 2005 Chemithon Enterprises

Nitrogen Purge SystemWhy nitrogen (N 2) Purge•Used to purgeunloading arm connections.•Eliminates NH 3fromconnections.•Eliminates O 2and H 2O fromEquipmententering the system.•N 2cylinder rack•Pressure reducing valve & pressure relief valve•Pressure gauge and switch to alarm is lowpressure supply.Copyright 2005 Chemithon Enterprises

Ammonia Unloading Bulkhead•Equipment•Two Unloading Arms: Vapor & Liquid•Automated liquid line valve, Emergencyvapor line valve.•Liquid line flow switch & vapor linepressure transmitterCopyright 2005 Chemithon Enterprises

Ammonia Storage TanksEquipment•Ammonia Storage Tanks, Rated265 to 300 Psig•Level, Pressure, and Liq.Temperature Transmitters•Level Switch, Pressure safetyvalve manifold•Piping system to select fill andsupply tank.Copyright 2005 Chemithon Enterprises

NH 3 Loading and StorageCopyright 2005 Chemithon Enterprises

Ammonia Pumping SystemsEquipment• Two Side Channel Pumps,one operates, one as inlinespare• Pressure Transmitter,• Piping and automatic valvesto select supply tankCopyright 2005 Chemithon Enterprises

NH 3 PumpingCopyright 2005 Chemithon Enterprises

Anhydrous Ammonia TankCopyright 2005 Chemithon Enterprises

Anhydrous Ammonia VaporizersEquipment•Vaporizers may use either Steam,Electricity or Hot Water•Two Vaporizers, one operates,one as inline spare•NH 3Pressure, NH 3and Outletwater Temperature Transmitters,•Piping and automatic valves toselect vaporizerCopyright 2005 Chemithon Enterprises

NH 3 VaporizingCopyright 2005 Chemithon Enterprises

Anhydrous Storage Tank and VaporizerSkidCopyright 2005 Chemithon Enterprises

Vaporizer Skid Control PanelsCopyright 2005 Chemithon Enterprises

Liquid Ammonia Piping•Do not block in piping system and components when full of liquidammonia. Thermal expansion of liquid ammonia will cause extremelyhigh pressures. Ballvalves forLiq. NH3 Volume vs Temperatureanhydrousammonia havevented balls.•Hydrostatic reliefvalves onpiping systemprevent overpressurizing.Volume (Ft^3/100Lbs)2.92.852.82.752.72.652.62.55-100.00 -50.00 0.00 50.00 100.00 150.00Temperature (F)Copyright 2005 Chemithon Enterprises

Ammonia Metering & Dilution AirSystemEquipment• Two dilution air blowers, one operates,one as inline spare• NH 3 and Air: Flow, Pressure &Temperature Transmitters• Piping and automatic valves to isolateNH3 vapor and to select the operatingblowerCopyright 2005 Chemithon Enterprises

Ammonia Metering & DilutionCopyright 2005 Chemithon Enterprises

Dilution Air SystemCopyright 2005 Chemithon Enterprises

Aqueous Ammonia• EPA Regulated Toxic Substance• High energy costs to evaporate water• 588 BTU/ lb NH 3• 1000 BTU/ lb Water• Additional heat required to prevent condensation• Concentration must be less than 20%• Transporting and Evaporating water• Higher Ammonia costsCopyright 2005 Chemithon Enterprises

Aqueous Ammonia System• Similar to Anhydrous Ammonia• Lower Pressure Storage Tanks• Fewer Safety Requirements• Uses much more energy to evaporateWaterCopyright 2005 Chemithon Enterprises

Energy Required to Evaporate NH 3AmmoniaConcentrationlbsNH 3LbsWater/lb NH 3BTU/lb NH 3Anhydrous 1 0 588NH 328% NH 31 2.57 3,15919.5% NH 31 4.13 4,716Copyright 2005 Chemithon Enterprises

Aqueous Ammonia Storage VesselCopyright 2005 Chemithon Enterprises

Pump SkidCopyright 2005 Chemithon Enterprises

Urea• Safe non toxic stable material• Primary active component in fertilizer• Readily available• Delivered costs per pound of ammonia lessthan aqueous ammonia• Typical delivered costs about 1.5 to 2 timesanhydrous per pound of ammoniaCopyright 2005 Chemithon Enterprises

Chemithon SafeDeNOx ®Urea‐to‐Ammonia ProcessUreaFeedSystemSafeDeNOx ®ReactorSystemAmmoniatoProcessUreaUreaStorageSystemSteamScrubberSystemUreaFeedSystemSafeDeNOx®ReactorSystemCopyright 2005 Chemithon Enterprises

Dry Urea Storage & UnloadingSILOSILO SILO SILOUREAFROMTRUCKDRY AIRTOTRUCKAIRDRYERUREATOSUPPLYSYSTEMCopyright 2005 Chemithon Enterprises

Dry Urea Storage• Truck can deliver up to 35 tons perload• Rail can deliver up to 100 tons perload• 1,100 pounds of ammonia per ton ofurea• Most economical form to store ureaCopyright 2005 Chemithon Enterprises

Dry Urea Storage Benefits•Lower operating cost ‐ no heatedtanks•Lower delivered cost•No spill containment requiredCopyright 2005 Chemithon Enterprises

Batch Urea Dissolving & StorageFIFEUREAFROMTRUCKCONDENSATEUREADISSOLVINGTANKFICFERECYCLEH.E.RECYCLEPUMPSTEAMCONDENSATESTEAMMAIN STORAGETANKUREA FEEDPUMPSCFICFEUREATOREACTORCONDENSATECopyright 2005 Chemithon Enterprises

Continuous Urea Dissolving Step• Can be continuous or batch• Requires density control• Mixing tanks are needed• Requires DI water service and storage• Best choice for smaller systemsCopyright 2005 Chemithon Enterprises

Continuous Urea DissolvingSystemUREAFROMSTORAGECONDENSATEUREADISSOLVERSTEAMCONDENSATESTEAMCONDENSATESCFICFEUREAPUMPUREATOREACTORCopyright 2005 Chemithon Enterprises

Urea Melter SystemUREAFROMSTORAGEUREAMELTERSTEAMCONDENSATESTEAMCONDENSATESCFICUREAPUMPFEUREATOREACTORCopyright 2005 Chemithon Enterprises

Urea Melter System• No de‐ionized water needed• Urea melts at 271°F (133°C)• Molten urea has a low viscosity and iseasily pumped• Similar to sulfur• Chemithon has over 40 years of experiencein melting and handling sulfurCopyright 2005 Chemithon Enterprises

SafeDeNOx ® Reactor SystemUREAFROMFEEDPUMPSAMMONIAPRODUCTSTEAMFEFICCONDENSATEFICFECONDENSATESTEAMSTEAMFEFICUREAREACTORCopyright 2005 Chemithon Enterprises

SafeDeNOx ® Process Reactions• Urea Decomposition• (NH 2 ) 2 CO +3H 2 O →CO 2 ↑ + 2NH 4 OHureawater carbon ammoniumdioxide hydroxide• Neutralization of MAP• 2NH 4 OH + 2NH 4 H 2 PO 4 →2(NH 4 ) 2 HPO 4 +2H 2 0“MAP”“DAP”• Decomposition of DAP• 2(NH 4 ) 2 HPO 4 →2NH 4 H 2 PO 4 + 2NH 3 ↑“DAP” “MAP” ammoniavaporCopyright 2005 Chemithon Enterprises

SafeDeNOx ® Overall Reaction• At equilibrium all three reactionsoccur simultaneously• Overall reaction• (NH 2 ) 2 CO + H2O → CO 2↑ + 2NH 3 ↑urea water carbon ammoniadioxide vaporCopyright 2005 Chemithon Enterprises

SafeDeNOx ® Catalyst Information• Mixture of Mono Ammonia dihydrogenPhosphate (MAP) and Di‐Ammonia hydrogen Phosphate (DAP)(excess)• It is a white, water‐soluble crystal,easy to add through the feed system.• 3,300 lbs (1,500 kg) of catalyst for 1,400lb/hr (635 kg/hr) reactorCopyright 2005 Chemithon Enterprises

SafeDeNOx ® Reactor System• Uses self‐regenerating catalyst to acceleratethe reaction• Mono‐ammonium phosphate (MAP)• Catalyst allows near stoichiometric levels• minimizes energy requirements• Approximately 3,500 BTU’s/lb (1,945 kcal/kg)NH 3Copyright 2005 Chemithon Enterprises

SafeDeNOx ® Response Rate50% Urea solution Feed Rate(lbs/hr)40035030025020015010050090% Response rate within 5MinutesFor a 55% change in demand.0 5 10 15 20 25 30Time (minutes)Ammonia FlowAmmonia Set PointUrea feed rateCopyright 2005 Chemithon Enterprises

SafeDeNOx ® Response RateFlow rate (Urea lbs/hr)400350300250200150100AmmoniaSet PointUrea Feed Rate5000 20 40 60 80 100 120 140 160Time (min.)Copyright 2005 Chemithon Enterprises

SafeDeNOx ® Benefits• Responds quickly to changes inammonia demand• Self‐regenerating catalystsignificantly reduces urea residencetime• Constant ammonia concentration(minimizes slip)Copyright 2005 Chemithon Enterprises

Startup of First CommercialSystem Reliability ‐ 98% AveragePlant Karn 1 & 2 AvailabilityPercent Availability10098969492June July August SeptemberCopyright 2005 Chemithon Enterprises

800 lb/hr (360 kg/hr) SafeDeNOx ®SystemCopyright 2005 Chemithon Enterprises

Urea Storage and HandlingCopyright 2005 Chemithon Enterprises

Urea Feeders & MelterCopyright 2005 Chemithon Enterprises

Thank youQuestionsCopyright 2005 Chemithon Enterprises