[{"data":1,"prerenderedAt":816},["ShallowReactive",2],{"site-footer-common":3,"glossary:gas-air-heater-gah-ggh":45,"glossary-related:gas-air-heater-gah-ggh":178},{"id":4,"extension":5,"footer":6,"meta":40,"navbar":41,"stem":43,"__hash__":44},"common\u002Fcommon.yml","yml",{"tagline":7,"links":8,"sections":9},"Acoustic cleaning intelligence for industrial fouling, soot, ash, dust and build-up.",[],[10,19,31],{"title":11,"links":12},"Product",[13,16],{"label":14,"to":15},"How it works","\u002F#product",{"label":17,"to":18},"Cost assessment","\u002F#hero",{"title":20,"links":21},"Company",[22,25,28],{"label":23,"to":24},"What we build","\u002F#about",{"label":26,"to":27},"Careers","\u002F#careers",{"label":29,"to":30},"Contact","\u002F#contact",{"title":32,"links":33},"Resources",[34,37],{"label":35,"to":36},"Blog","\u002Fresources\u002Fblog",{"label":38,"to":39},"Glossary","\u002Fglossary",{},{"links":42},[],"common","YocmZRy1AYfBbpgGVms-zhdiABlF8VTxHx6h4rDmZBA",{"id":46,"title":47,"aliases":48,"body":52,"category":157,"description":158,"extension":159,"meta":160,"navigation":161,"path":162,"relatedTerms":163,"seo":168,"sources":171,"stem":175,"term":176,"__hash__":177},"glossary\u002Fglossary\u002Fgas-air-heater-gah-ggh.md","Gas-air heater (GAH \u002F GGH)",[49,50,51],"GAH","GGH","gas-gas heater",{"type":53,"value":54,"toc":150},"minimark",[55,74,79,105,109,122,126],[56,57,58,59,63,64,69,70,73],"p",{},"A ",[60,61,62],"strong",{},"gas-air heater (GAH)"," transfers heat from hot flue gas to cooler combustion air — functionally the same as the boiler ",[65,66,68],"a",{"href":67},"\u002Fglossary\u002Fair-heater","air heater",", with the term GAH used more often in cement-plant and metallurgical contexts. A ",[60,71,72],{},"gas-gas heater (GGH)"," transfers heat between two flue-gas streams, most commonly used in FGD installations to reheat scrubbed (cooled) flue gas before stack discharge so plume buoyancy and dispersion meet permit requirements.",[75,76,78],"h2",{"id":77},"configurations","Configurations",[80,81,82,93,99],"ul",{},[83,84,85,88,89],"li",{},[60,86,87],{},"Regenerative GAH\u002FGGH"," — rotating matrix like a ",[65,90,92],{"href":91},"\u002Fglossary\u002Fljungstrom-air-preheater","Ljungström",[83,94,95,98],{},[60,96,97],{},"Recuperative GAH\u002FGGH"," — fixed tube bundle",[83,100,101,104],{},[60,102,103],{},"Heat-pipe GAH\u002FGGH"," — sealed two-phase fluid in tubes, no moving parts",[75,106,108],{"id":107},"fouling-and-cleaning","Fouling and cleaning",[56,110,111,112,116,117,121],{},"GAH and GGH baskets and tubes foul with ash and (on units downstream of FGD) calcium-rich sulphite or sulphate deposits. Cleaning options follow the same pattern as for the boiler air heater: steam ",[65,113,115],{"href":114},"\u002Fglossary\u002Fsteam-sootblower","sootblowing",", ",[65,118,120],{"href":119},"\u002Fglossary\u002Fsonic-horn","sonic horns",", and periodic water washing during major outages.",[75,123,125],{"id":124},"related-terms","Related terms",[80,127,128,133,138,144],{},[83,129,130],{},[65,131,132],{"href":67},"Air heater",[83,134,135],{},[65,136,137],{"href":91},"Ljungström air preheater",[83,139,140],{},[65,141,143],{"href":142},"\u002Fglossary\u002Felectrostatic-precipitator","Electrostatic precipitator",[83,145,146],{},[65,147,149],{"href":148},"\u002Fglossary\u002Fselective-catalytic-reduction","Selective Catalytic Reduction (SCR)",{"title":151,"searchDepth":152,"depth":152,"links":153},"",2,[154,155,156],{"id":77,"depth":152,"text":78},{"id":107,"depth":152,"text":108},{"id":124,"depth":152,"text":125},"hrsg-gas-path","A gas-air heater (GAH) transfers heat from hot flue gas to cooler combustion air — functionally the same as the boiler air heater, with the term GAH used more often in cement-plant and metallurgical contexts. A gas-gas heater (GGH) transfers heat between two flue-gas streams, most commonly used in FGD installations to reheat scrubbed (cooled) flue gas before stack discharge so plume buoyancy and dispersion meet permit requirements.","md",{},true,"\u002Fglossary\u002Fgas-air-heater-gah-ggh",[164,165,166,167],"air-heater","ljungstrom-air-preheater","electrostatic-precipitator","selective-catalytic-reduction",{"title":169,"description":170},"Gas-air heater (GAH) and gas-gas heater (GGH) — flue-gas reheating equipment","GAHs preheat combustion air with flue-gas heat (like an air heater). GGHs transfer heat between two flue-gas streams, typically reheating scrubbed gas before the stack.",[172],{"title":173,"url":174},"Wikipedia — Air preheater","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAir_preheater","glossary\u002Fgas-air-heater-gah-ggh","Gas-air heater and gas-gas heater","2LMRKO9eCK-udndrjaeTnw2JoRl9SthnW71xK6BXNXI",[179,365,476,656],{"id":180,"title":181,"aliases":182,"body":186,"category":350,"description":351,"extension":159,"meta":352,"navigation":161,"path":67,"relatedTerms":353,"seo":358,"sources":361,"stem":363,"term":132,"__hash__":364},"glossary\u002Fglossary\u002Fair-heater.md","Air heater (APH)",[183,184,185],"air preheater","APH","air heaters",{"type":53,"value":187,"toc":344},[188,202,206,255,259,271,300,304,310,312],[56,189,190,191,193,194,196,197,201],{},"An ",[60,192,68],{}," — also called an ",[60,195,183],{}," (APH) — is the final heat-recovery device in a boiler's ",[65,198,200],{"href":199},"\u002Fglossary\u002Fconvective-pass-backpass","convective pass",", recovering low-grade heat from cooling flue gas to preheat the combustion air. APHs lift overall boiler efficiency by 5–10 percentage points and are critical to heat-rate performance.",[75,203,205],{"id":204},"aph-types","APH types",[207,208,209,222],"table",{},[210,211,212],"thead",{},[213,214,215,219],"tr",{},[216,217,218],"th",{},"Type",[216,220,221],{},"Description",[223,224,225,236,247],"tbody",{},[213,226,227,233],{},[228,229,230],"td",{},[65,231,232],{"href":91},"Ljungström \u002F regenerative",[228,234,235],{},"Rotating matrix of heat-exchange baskets cycling between gas and air sides",[213,237,238,244],{},[228,239,240],{},[65,241,243],{"href":242},"\u002Fglossary\u002Ftubular-air-preheater","Tubular",[228,245,246],{},"Fixed tube bundle with flue gas through tubes, air around them",[213,248,249,252],{},[228,250,251],{},"Plate-type",[228,253,254],{},"Cross-flow plate exchanger; smaller industrial duty",[75,256,258],{"id":257},"the-cold-end-problem","The cold-end problem",[56,260,261,262,265,266,270],{},"The APH cold end is the coolest point in the flue-gas path before the ",[65,263,264],{"href":142},"ESP"," \u002F ",[65,267,269],{"href":268},"\u002Fglossary\u002Fbaghouse","baghouse",". Two related failure modes dominate:",[80,272,273,286],{},[83,274,275,281,282,285],{},[60,276,277],{},[65,278,280],{"href":279},"\u002Fglossary\u002Fammonium-bisulphate","Ammonium bisulphate (ABS)"," fouling on boilers with upstream ",[65,283,284],{"href":148},"SCR",": sticky deposits plug Ljungström baskets and tubular APH tubes",[83,287,288,294,295,299],{},[60,289,290],{},[65,291,293],{"href":292},"\u002Fglossary\u002Fcold-end-corrosion-dew-point-corrosion","Cold-end corrosion"," below the ",[65,296,298],{"href":297},"\u002Fglossary\u002Facid-dew-point","acid dew point"," — sulphuric acid condenses and attacks baskets and tubes",[75,301,303],{"id":302},"why-sonic-horns-are-routinely-specified-on-aphs","Why sonic horns are routinely specified on APHs",[56,305,306,307,309],{},"ABS fouling is the single most common reason plants install ",[65,308,120],{"href":119}," on the cold end. Continuous low-amplitude vibration prevents ABS from consolidating between water-wash campaigns, extending the campaign interval from quarterly to annual and avoiding capacity-derate excursions.",[75,311,125],{"id":124},[80,313,314,320,324,329,334,339],{},[83,315,316],{},[65,317,319],{"href":318},"\u002Fglossary\u002Fboiler","Boiler",[83,321,322],{},[65,323,137],{"href":91},[83,325,326],{},[65,327,328],{"href":242},"Tubular air preheater",[83,330,331],{},[65,332,333],{"href":279},"Ammonium bisulphate",[83,335,336],{},[65,337,338],{"href":292},"Cold-end corrosion \u002F dew-point corrosion",[83,340,341],{},[65,342,343],{"href":119},"Sonic horn",{"title":151,"searchDepth":152,"depth":152,"links":345},[346,347,348,349],{"id":204,"depth":152,"text":205},{"id":257,"depth":152,"text":258},{"id":302,"depth":152,"text":303},{"id":124,"depth":152,"text":125},"boiler","An air heater — also called an air preheater (APH) — is the final heat-recovery device in a boiler's convective pass, recovering low-grade heat from cooling flue gas to preheat the combustion air. APHs lift overall boiler efficiency by 5–10 percentage points and are critical to heat-rate performance.",{},[350,165,354,355,356,357],"tubular-air-preheater","ammonium-bisulphate","cold-end-corrosion-dew-point-corrosion","sonic-horn",{"title":359,"description":360},"Air heater (APH) — final flue-gas heat-recovery device before the stack","An air heater (also air preheater, APH) recovers low-grade heat from flue gas to preheat combustion air. Cold-end fouling and corrosion are the dominant operational challenges.",[362],{"title":173,"url":174},"glossary\u002Fair-heater","3pBQ2ZyiQ7VOKuf9rxsx43EFarkhgykVhd2amXg0TMY",{"id":366,"title":137,"aliases":367,"body":371,"category":350,"description":464,"extension":159,"meta":465,"navigation":161,"path":91,"relatedTerms":466,"seo":467,"sources":470,"stem":474,"term":137,"__hash__":475},"glossary\u002Fglossary\u002Fljungstrom-air-preheater.md",[368,369,370],"Ljungstrom APH","regenerative air preheater","rotary APH",{"type":53,"value":372,"toc":458},[373,382,386,389,413,417,428,432,438,440],[56,374,375,376,378,379,381],{},"The ",[60,377,137],{}," is a regenerative-type ",[65,380,68],{"href":67}," using a rotating matrix of heat-exchange baskets that cycle between the flue-gas and combustion-air sides of the boiler. As the matrix rotates (typically at 1–3 rpm), each basket alternately absorbs heat from the hot flue gas and releases it to the cold combustion air. Patented by Frederik Ljungström in 1920, it is the dominant utility-scale APH design worldwide.",[75,383,385],{"id":384},"basket-arrangement","Basket arrangement",[56,387,388],{},"A typical Ljungström has hot-end, intermediate and cold-end basket layers, each chosen for its operating-temperature band:",[80,390,391,397,403],{},[83,392,393,396],{},[60,394,395],{},"Hot end"," — flat, robust, large-pitch baskets",[83,398,399,402],{},[60,400,401],{},"Intermediate"," — moderate-pitch",[83,404,405,408,409],{},[60,406,407],{},"Cold end"," — small-pitch, high-surface-area baskets — ",[410,411,412],"em",{},"and the most fouling-prone",[75,414,416],{"id":415},"cold-end-fouling","Cold-end fouling",[56,418,419,420,423,424,427],{},"The cold-end baskets are the smallest and most easily plugged. Two failure modes dominate: ",[65,421,422],{"href":279},"ammonium-bisulphate (ABS)"," deposition on SCR-equipped units, and ",[65,425,426],{"href":292},"cold-end corrosion"," below the acid dew point. Fouled cold-end baskets raise APH ΔP, derate the ID fan, and ultimately force a full water-wash campaign.",[75,429,431],{"id":430},"cleaning","Cleaning",[56,433,434,437],{},[65,435,436],{"href":119},"Sonic horns"," mounted on the cold-end gas side keep baskets clear between periodic steam-sootblower passes, extending the interval to full water-wash from quarterly to annual on many units.",[75,439,125],{"id":124},[80,441,442,446,450,454],{},[83,443,444],{},[65,445,132],{"href":67},[83,447,448],{},[65,449,328],{"href":242},[83,451,452],{},[65,453,333],{"href":279},[83,455,456],{},[65,457,343],{"href":119},{"title":151,"searchDepth":152,"depth":152,"links":459},[460,461,462,463],{"id":384,"depth":152,"text":385},{"id":415,"depth":152,"text":416},{"id":430,"depth":152,"text":431},{"id":124,"depth":152,"text":125},"The Ljungström air preheater is a regenerative-type air heater using a rotating matrix of heat-exchange baskets that cycle between the flue-gas and combustion-air sides of the boiler. As the matrix rotates (typically at 1–3 rpm), each basket alternately absorbs heat from the hot flue gas and releases it to the cold combustion air. Patented by Frederik Ljungström in 1920, it is the dominant utility-scale APH design worldwide.",{},[164,354,355,357],{"title":468,"description":469},"Ljungström air preheater — rotating-basket regenerative APH design","A Ljungström air preheater uses a rotating matrix of heat-exchange baskets that cycle between the flue-gas and combustion-air sides. The dominant utility APH design worldwide.",[471],{"title":472,"url":473},"Wikipedia — Ljungström air preheater","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FLjungstr%C3%B6m_air_preheater","glossary\u002Fljungstrom-air-preheater","GkwHkh96PaXY9tkG7lFEJIaZkCSSagWSxoQsQnFXtBE",{"id":477,"title":478,"aliases":479,"body":482,"category":631,"description":632,"extension":159,"meta":633,"navigation":161,"path":142,"relatedTerms":634,"seo":641,"sources":644,"stem":654,"term":143,"__hash__":655},"glossary\u002Fglossary\u002Felectrostatic-precipitator.md","Electrostatic precipitator (ESP)",[264,480,481],"electrostatic precipitators","dry ESP",{"type":53,"value":483,"toc":625},[484,499,503,521,525,561,565,597,599],[56,485,190,486,489,490,494,495,498],{},[60,487,488],{},"electrostatic precipitator (ESP)"," is an air-pollution-control device that removes particulate matter from a flue-gas stream by electrostatically charging dust particles and collecting them on grounded plate electrodes. ESPs are the dominant particulate-control technology on coal-fired boilers, cement kilns, ",[65,491,493],{"href":492},"\u002Fglossary\u002Fwaste-to-energy","waste-to-energy"," plants, ",[65,496,497],{"href":492},"biomass"," plants, sinter strands and many other heavy-industry off-gas streams.",[75,500,502],{"id":501},"how-an-esp-works","How an ESP works",[56,504,505,506,510,511,515,516,520],{},"Flue gas flows horizontally between a parallel array of vertical ",[65,507,509],{"href":508},"\u002Fglossary\u002Fcollecting-electrode","collecting electrodes"," (plates) and ",[65,512,514],{"href":513},"\u002Fglossary\u002Fdischarge-electrode","discharge electrodes"," (high-voltage wires or rigid spikes). A negative DC potential of 40–80 kV applied to the discharge electrodes generates a ",[65,517,519],{"href":518},"\u002Fglossary\u002Fcorona-discharge","corona discharge"," that ionises the gas. Charged dust particles drift to the collecting plates, accumulate as a dust layer, are rapped down into hoppers below and removed by ash-handling equipment.",[75,522,524],{"id":523},"where-sonic-horns-fit","Where sonic horns fit",[56,526,527,528,532,533,535,536,540,541,545,546,550,551,555,556,560],{},"ESPs accumulate dust faster than mechanical rapping can release it, and hoppers below ESP fields routinely ",[65,529,531],{"href":530},"\u002Fglossary\u002Fbridging","bridge"," and choke. ",[65,534,436],{"href":119}," installed on the ESP ",[65,537,539],{"href":538},"\u002Fglossary\u002Fesp-penthouse","penthouse"," and on hopper walls keep dust dislodged, supplement ",[65,542,544],{"href":543},"\u002Fglossary\u002Fesp-rapper","rappers",", prevent ",[65,547,549],{"href":548},"\u002Fglossary\u002Fback-corona","back-corona"," by limiting plate dust thickness, and eliminate hopper ",[65,552,554],{"href":553},"\u002Fglossary\u002Frat-holing","rat-holing"," without the structural fatigue of ",[65,557,559],{"href":558},"\u002Fglossary\u002Ftumbling-hammer-rapper","tumbling-hammer rappers",".",[75,562,564],{"id":563},"common-failure-modes","Common failure modes",[80,566,567,573,579,585,591],{},[83,568,569,572],{},[60,570,571],{},"High opacity \u002F particulate emissions"," from thick dust layers reducing collection efficiency",[83,574,575,578],{},[60,576,577],{},"Back-corona"," in high-resistivity ash that reverses ionisation and collapses collection",[83,580,581,584],{},[60,582,583],{},"Re-entrainment"," as rapper puffs return dust to the gas stream",[83,586,587,590],{},[60,588,589],{},"Hopper bridging"," that stops ash extraction and triggers field shutdowns",[83,592,593,596],{},[60,594,595],{},"Discharge-electrode breakage"," from rapper fatigue or sparking",[75,598,125],{"id":124},[80,600,601,606,611,615,621],{},[83,602,603],{},[65,604,605],{"href":508},"Collecting electrode",[83,607,608],{},[65,609,610],{"href":513},"Discharge electrode",[83,612,613],{},[65,614,577],{"href":548},[83,616,617],{},[65,618,620],{"href":619},"\u002Fglossary\u002Fesp-hopper","ESP hopper",[83,622,623],{},[65,624,343],{"href":119},{"title":151,"searchDepth":152,"depth":152,"links":626},[627,628,629,630],{"id":501,"depth":152,"text":502},{"id":523,"depth":152,"text":524},{"id":563,"depth":152,"text":564},{"id":124,"depth":152,"text":125},"esp","An electrostatic precipitator (ESP) is an air-pollution-control device that removes particulate matter from a flue-gas stream by electrostatically charging dust particles and collecting them on grounded plate electrodes. ESPs are the dominant particulate-control technology on coal-fired boilers, cement kilns, waste-to-energy plants, biomass plants, sinter strands and many other heavy-industry off-gas streams.",{},[635,636,637,638,639,640,549,357],"wet-esp","collecting-electrode","discharge-electrode","corona-discharge","esp-hopper","esp-rapper",{"title":642,"description":643},"Electrostatic precipitator (ESP) — how it works and how it fouls","An ESP removes particulate from flue gas by charging dust and collecting it on plate electrodes. Sonic horns are widely used to dislodge ash from plates and to keep hoppers from bridging.",[645,648,651],{"title":646,"url":647},"Wikipedia — Electrostatic precipitator","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FElectrostatic_precipitator",{"title":649,"url":650},"EPA — Monitoring Knowledge Base: Electrostatic Precipitators","https:\u002F\u002Fwww.epa.gov\u002Fair-emissions-monitoring-knowledge-base\u002Fmonitoring-control-technique-electrostatic-precipitators",{"title":652,"url":653},"Babcock & Wilcox — Basics of ESP Operation","https:\u002F\u002Fwww.babcock.com\u002Fhome\u002Fabout\u002Fresources\u002Flearning-center\u002Fbasic-esp-operation","glossary\u002Felectrostatic-precipitator","hT_C4hmid3iZaYWhLpiSJ2tBfL0bSJ-uhzn7TY4Vtj4",{"id":657,"title":149,"aliases":658,"body":661,"category":792,"description":793,"extension":159,"meta":794,"navigation":161,"path":148,"relatedTerms":795,"seo":803,"sources":806,"stem":813,"term":814,"__hash__":815},"glossary\u002Fglossary\u002Fselective-catalytic-reduction.md",[284,659,660],"SCR system","SCR reactor",{"type":53,"value":662,"toc":787},[663,679,683,699,701,704,733,747,749],[56,664,665,667,668,672,673,675,676,678],{},[60,666,149],{}," is the dominant flue-gas NOx-control technology on coal-fired and gas-fired utility boilers, ",[65,669,671],{"href":670},"\u002Fglossary\u002Fheat-recovery-steam-generator","HRSGs"," in combined-cycle plants, ",[65,674,493],{"href":492}," and ",[65,677,497],{"href":492}," boilers, cement plants and major refining furnaces. Ammonia or aqueous urea is injected upstream of a catalyst bed; the catalyst lowers the activation energy for the reaction NOx + NH₃ → N₂ + H₂O, achieving 80–95% NOx reduction across the reactor.",[75,680,682],{"id":681},"reactor-layout","Reactor layout",[56,684,685,686,690,691,694,695,698],{},"A typical SCR reactor is a vertical or horizontal duct containing 2–4 layers of catalyst modules. Upstream of the catalyst sits the ",[65,687,689],{"href":688},"\u002Fglossary\u002Fammonia-injection-grid","ammonia injection grid (AIG)"," that distributes the ammonia evenly into the flue gas. Most installations operate in the ",[60,692,693],{},"high-dust"," position (between economiser and air heater) where catalyst temperature is around 300–400 °C; ",[60,696,697],{},"tail-end"," SCRs sit downstream of particulate control at lower temperatures, with the trade-off of needing flue-gas reheating.",[75,700,108],{"id":107},[56,702,703],{},"SCR catalysts foul in two ways:",[80,705,706,724],{},[83,707,708,714,715,675,719,723],{},[60,709,710],{},[65,711,713],{"href":712},"\u002Fglossary\u002Fcatalyst-pluggage","Pluggage"," — fly ash, ",[65,716,718],{"href":717},"\u002Fglossary\u002Fpopcorn-ash","popcorn ash",[65,720,722],{"href":721},"\u002Fglossary\u002Flarge-particle-ash","large-particle ash"," wedge into the catalyst cells, blocking the gas path",[83,725,726,732],{},[60,727,728],{},[65,729,731],{"href":730},"\u002Fglossary\u002Fcatalyst-masking","Masking"," — a thin layer of deposit covers the active sites; gas flow continues but catalytic activity falls",[56,734,735,736,740,741,116,744,746],{},"Both reduce NOx-reduction efficiency, raise ",[65,737,739],{"href":738},"\u002Fglossary\u002Fammonia-slip","ammonia slip",", and shorten catalyst life. Cleaning options include steam ",[65,742,743],{"href":114},"sootblowers",[65,745,120],{"href":119}," and offline campaigns (vacuum \u002F water wash \u002F regeneration). Sonic horns are increasingly favoured because they continuously dislodge ash before it cements onto the catalyst face, without the steam erosion of mechanical sootblowing.",[75,748,125],{"id":124},[80,750,751,757,762,767,772,777,783],{},[83,752,753],{},[65,754,756],{"href":755},"\u002Fglossary\u002Fselective-non-catalytic-reduction","Selective Non-Catalytic Reduction (SNCR)",[83,758,759],{},[65,760,761],{"href":688},"Ammonia injection grid",[83,763,764],{},[65,765,766],{"href":738},"Ammonia slip",[83,768,769],{},[65,770,771],{"href":730},"Catalyst masking",[83,773,774],{},[65,775,776],{"href":712},"Catalyst pluggage",[83,778,779],{},[65,780,782],{"href":781},"\u002Fglossary\u002Fhoneycomb-catalyst","Honeycomb catalyst",[83,784,785],{},[65,786,343],{"href":119},{"title":151,"searchDepth":152,"depth":152,"links":788},[789,790,791],{"id":681,"depth":152,"text":682},{"id":107,"depth":152,"text":108},{"id":124,"depth":152,"text":125},"scr-sncr","Selective Catalytic Reduction (SCR) is the dominant flue-gas NOx-control technology on coal-fired and gas-fired utility boilers, HRSGs in combined-cycle plants, waste-to-energy and biomass boilers, cement plants and major refining furnaces. Ammonia or aqueous urea is injected upstream of a catalyst bed; the catalyst lowers the activation energy for the reaction NOx + NH₃ → N₂ + H₂O, achieving 80–95% NOx reduction across the reactor.",{},[796,797,798,799,800,801,802,357],"selective-non-catalytic-reduction","denox","ammonia-injection-grid","ammonia-slip","catalyst-masking","catalyst-pluggage","honeycomb-catalyst",{"title":804,"description":805},"Selective Catalytic Reduction (SCR) — how the dominant NOx-control technology works","SCR is the dominant NOx-control technology on industrial combustion plant. Ammonia is injected upstream of a catalyst that converts NOx to nitrogen and water.",[807,810],{"title":808,"url":809},"Wikipedia — Selective catalytic reduction","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSelective_catalytic_reduction",{"title":811,"url":812},"Power Engineering — SCR Catalyst Cleaning: Sootblowers vs. Acoustic Horns","https:\u002F\u002Fwww.power-eng.com\u002Foperations-maintenance\u002Fscr-catalyst-cleaningsootblowers-vs-acoustic-horns\u002F","glossary\u002Fselective-catalytic-reduction","Selective Catalytic Reduction","fmMCMd4NY3eZdSk_UYlbZ9ryi-9CR2Os6DivQjXEPCU",1782613743252]