[{"data":1,"prerenderedAt":863},["ShallowReactive",2],{"site-footer-common":3,"glossary:straw-agricultural-residue-firing":45,"glossary-related:straw-agricultural-residue-firing":195},{"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":175,"description":176,"extension":177,"meta":178,"navigation":179,"path":180,"relatedTerms":181,"seo":186,"sources":189,"stem":193,"term":61,"__hash__":194},"glossary\u002Fglossary\u002Fstraw-agricultural-residue-firing.md","Straw \u002F agricultural-residue firing",[49,50,51],"straw firing","agricultural residue boiler","ag-residue firing",{"type":53,"value":54,"toc":168},"minimark",[55,74,79,115,123,127,140,144],[56,57,58,62,63,68,69,73],"p",{},[59,60,61],"strong",{},"Straw and agricultural-residue firing"," — wheat straw, rice straw, corn stover, palm fronds — is a regionally important biomass-energy practice, dominant in Denmark, parts of Germany, China, India and Spain. Crops are baled or pelletised and burned in dedicated boilers, typically ",[64,65,67],"a",{"href":66},"\u002Fglossary\u002Fbfb-boiler","BFB"," or ",[64,70,72],{"href":71},"\u002Fglossary\u002Fcfb-boiler","CFB"," designs that tolerate the difficult ash chemistry.",[75,76,78],"h2",{"id":77},"why-straw-is-hard-to-burn","Why straw is hard to burn",[80,81,82,89,99,109],"ul",{},[83,84,85,88],"li",{},[59,86,87],{},"Very high potassium content"," — K₂O often 10–25% of ash; far above wood",[83,90,91,94,95],{},[59,92,93],{},"High chlorine content"," — particularly rice and wheat straw; drives ",[64,96,98],{"href":97},"\u002Fglossary\u002Fchloride-induced-corrosion","chloride corrosion",[83,100,101,104,105],{},[59,102,103],{},"Low ash-melting temperature"," — KCl-rich ash melts at 700–800 °C and bonds to tubes as ",[64,106,108],{"href":107},"\u002Fglossary\u002Flow-melt-sticky-ash","low-melt sticky ash",[83,110,111,114],{},[59,112,113],{},"Silica content"," — abrasive on grates and bed materials",[56,116,117,118,122],{},"The combination defeats steady-state operation on conventional designs and accelerates ",[64,119,121],{"href":120},"\u002Fglossary\u002Ftube-erosion-tube-wastage","tube wastage"," faster than any fossil-fuel-only boiler would experience.",[75,124,126],{"id":125},"cleaning","Cleaning",[56,128,129,130,134,135,139],{},"Straw-fired boilers are challenging acoustic-cleaning targets but also where the technology earns the most operational value. ",[64,131,133],{"href":132},"\u002Fglossary\u002Fsonic-horn","Sonic horns"," on the superheater, ",[64,136,138],{"href":137},"\u002Fglossary\u002Fgenerating-bank","generating bank"," and economiser keep deposits from consolidating into the unrecoverable bonded slag that would otherwise force frequent water-washing.",[75,141,143],{"id":142},"related-terms","Related terms",[80,145,146,152,157,162],{},[83,147,148],{},[64,149,151],{"href":150},"\u002Fglossary\u002Falkali-metals-in-ash","Alkali metals in ash",[83,153,154],{},[64,155,156],{"href":97},"Chloride-induced corrosion",[83,158,159],{},[64,160,161],{"href":107},"Low-melt sticky ash",[83,163,164],{},[64,165,167],{"href":166},"\u002Fglossary\u002Fboiler","Boiler",{"title":169,"searchDepth":170,"depth":170,"links":171},"",2,[172,173,174],{"id":77,"depth":170,"text":78},{"id":125,"depth":170,"text":126},{"id":142,"depth":170,"text":143},"wte-biomass","Straw and agricultural-residue firing — wheat straw, rice straw, corn stover, palm fronds — is a regionally important biomass-energy practice, dominant in Denmark, parts of Germany, China, India and Spain. Crops are baled or pelletised and burned in dedicated boilers, typically BFB or CFB designs that tolerate the difficult ash chemistry.","md",{},true,"\u002Fglossary\u002Fstraw-agricultural-residue-firing",[182,183,184,185],"alkali-metals-in-ash","chloride-induced-corrosion","low-melt-sticky-ash","boiler",{"title":187,"description":188},"Straw and agricultural-residue firing — high-alkali biomass for energy","Straw and other agricultural residues are burned in dedicated biomass boilers, primarily in Denmark, Germany, China and India. High potassium and chlorine produce aggressive fouling.",[190],{"title":191,"url":192},"Wikipedia — Biomass heating system","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FBiomass_heating_system","glossary\u002Fstraw-agricultural-residue-firing","fNE6ldjhyEIdgA756q7Khe-ujo4Eoo7Gbps1C74FVyM",[196,387,513,628],{"id":197,"title":151,"aliases":198,"body":202,"category":175,"description":372,"extension":177,"meta":373,"navigation":179,"path":150,"relatedTerms":374,"seo":378,"sources":381,"stem":385,"term":151,"__hash__":386},"glossary\u002Fglossary\u002Falkali-metals-in-ash.md",[199,200,201],"sodium in ash","potassium in ash","alkali loading",{"type":53,"value":203,"toc":366},[204,215,219,299,303,332,334,341,343],[56,205,206,209,210,214],{},[59,207,208],{},"Alkali metals"," — primarily sodium (Na) and potassium (K) — are the dominant drivers of low-melting fouling in biomass, ",[64,211,213],{"href":212},"\u002Fglossary\u002Fwaste-to-energy","waste-to-energy"," and certain coal boilers. Alkali compounds (KCl, NaCl, K₂SO₄, Na₂SO₄) melt or soften at temperatures (650–900 °C) lower than typical convective-pass tube-metal temperatures, so they arrive at the tube surface partly molten and bond tenaciously.",[75,216,218],{"id":217},"where-alkali-concentration-is-high","Where alkali concentration is high",[220,221,222,235],"table",{},[223,224,225],"thead",{},[226,227,228,232],"tr",{},[229,230,231],"th",{},"Fuel",[229,233,234],{},"Approximate alkali-in-ash range",[236,237,238,247,259,270,281,291],"tbody",{},[226,239,240,244],{},[241,242,243],"td",{},"Wood (clean stems)",[241,245,246],{},"Low (1–5%)",[226,248,249,256],{},[241,250,251,252],{},"Bark, ",[64,253,255],{"href":254},"\u002Fglossary\u002Fhog-fuel","hog fuel",[241,257,258],{},"Medium (5–15%)",[226,260,261,267],{},[241,262,263,264],{},"Straw and ",[64,265,266],{"href":180},"agricultural residues",[241,268,269],{},"High (10–25%)",[226,271,272,278],{},[241,273,274],{},[64,275,277],{"href":276},"\u002Fglossary\u002Fbagasse","Bagasse",[241,279,280],{},"Medium-high",[226,282,283,288],{},[241,284,285],{},[64,286,287],{"href":212},"MSW \u002F RDF \u002F SRF",[241,289,290],{},"High (variable)",[226,292,293,296],{},[241,294,295],{},"Coal",[241,297,298],{},"Low",[75,300,302],{"id":301},"operational-consequences","Operational consequences",[80,304,305,310,316,323],{},[83,306,307,309],{},[64,308,161],{"href":107}," bonding to superheater and economiser tubes",[83,311,312,313,315],{},"Accelerated ",[64,314,121],{"href":120}," from corrosive deposits",[83,317,318,322],{},[64,319,321],{"href":320},"\u002Fglossary\u002Fcatalyst-poisoning","SCR catalyst poisoning"," by alkali species",[83,324,325,326,328,329,331],{},"Bed-material agglomeration in ",[64,327,67],{"href":66}," and ",[64,330,72],{"href":71}," boilers",[75,333,126],{"id":125},[56,335,336,337,340],{},"Active ",[64,338,339],{"href":132},"sonic-horn"," cleaning prevents fresh alkali-rich deposits from consolidating into bonded slag, which is the only practical mitigation short of fuel substitution.",[75,342,143],{"id":142},[80,344,345,349,353,358,362],{},[83,346,347],{},[64,348,161],{"href":107},[83,350,351],{},[64,352,156],{"href":97},[83,354,355],{},[64,356,357],{"href":320},"Catalyst poisoning",[83,359,360],{},[64,361,277],{"href":276},[83,363,364],{},[64,365,47],{"href":180},{"title":169,"searchDepth":170,"depth":170,"links":367},[368,369,370,371],{"id":217,"depth":170,"text":218},{"id":301,"depth":170,"text":302},{"id":125,"depth":170,"text":126},{"id":142,"depth":170,"text":143},"Alkali metals — primarily sodium (Na) and potassium (K) — are the dominant drivers of low-melting fouling in biomass, waste-to-energy and certain coal boilers. Alkali compounds (KCl, NaCl, K₂SO₄, Na₂SO₄) melt or soften at temperatures (650–900 °C) lower than typical convective-pass tube-metal temperatures, so they arrive at the tube surface partly molten and bond tenaciously.",{},[184,183,375,376,377],"catalyst-poisoning","bagasse","straw-agricultural-residue-firing",{"title":379,"description":380},"Alkali metals in ash — sodium and potassium drive low-melt biomass fouling","Alkali metals (Na, K) in biomass and waste-fuel ash form low-melting compounds that bond to boiler tubes as sticky deposits and poison SCR catalysts.",[382],{"title":383,"url":384},"Wikipedia — Slagging and fouling in boilers","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FBoiler#Slagging","glossary\u002Falkali-metals-in-ash","geS4Q08TCk13dlbSDSxT-BXr_OYi5LW7UIKYIEm_0_0",{"id":388,"title":156,"aliases":389,"body":392,"category":175,"description":499,"extension":177,"meta":500,"navigation":179,"path":97,"relatedTerms":501,"seo":504,"sources":507,"stem":511,"term":156,"__hash__":512},"glossary\u002Fglossary\u002Fchloride-induced-corrosion.md",[390,98,391],"Cl corrosion","high-temperature chloride corrosion",{"type":53,"value":393,"toc":493},[394,407,411,414,418,434,438,465,467],[56,395,396,398,399,402,403,406],{},[59,397,156],{}," is the accelerated tube-wall thinning caused by chlorine-rich deposits on the steam-side surfaces of ",[64,400,401],{"href":212},"WtE",", ",[64,404,405],{"href":212},"biomass"," and waste-fired boilers. Chloride corrosion is the dominant tube-failure mechanism in WtE and a major maintenance cost driver.",[75,408,410],{"id":409},"mechanism","Mechanism",[56,412,413],{},"Chlorine in the fuel enters the gas phase as HCl and metal chlorides. Inside a thin deposit on the tube, chloride and metal-chloride species shuttle electrons between the gas atmosphere and the tube surface. The result is rapid metal loss far in excess of what the temperature alone would predict. The \"active oxidation\" mechanism describes one variant; chloride attack on the protective oxide scale describes another.",[75,415,417],{"id":416},"where-it-dominates","Where it dominates",[80,419,420,423,428,431],{},[83,421,422],{},"WtE superheaters — design temperatures kept low (380–420 °C) specifically to limit chloride corrosion",[83,424,425,426],{},"Straw-fired boilers — see ",[64,427,49],{"href":180},[83,429,430],{},"RDF \u002F SRF boilers — variable but generally high",[83,432,433],{},"Heavy-petroleum-fired boilers with chloride contamination",[75,435,437],{"id":436},"mitigation","Mitigation",[80,439,440,446,452,458],{},[83,441,442,445],{},[59,443,444],{},"Material selection"," — Inconel-625 weld overlays, nickel-based alloys on the most-exposed tubes",[83,447,448,451],{},[59,449,450],{},"Lower steam temperature"," at the superheater outlet to keep tube-metal below the corrosion threshold",[83,453,454,457],{},[59,455,456],{},"Fuel control"," — limit chloride loading where the contract permits",[83,459,460,464],{},[59,461,462],{},[64,463,133],{"href":132}," — preventing deposits from consolidating reduces the chloride concentration immediately adjacent to the tube surface, indirectly slowing corrosion",[75,466,143],{"id":142},[80,468,469,474,478,482,488],{},[83,470,471],{},[64,472,473],{"href":212},"Waste-to-energy",[83,475,476],{},[64,477,151],{"href":150},[83,479,480],{},[64,481,161],{"href":107},[83,483,484],{},[64,485,487],{"href":486},"\u002Fglossary\u002Fcold-end-corrosion-dew-point-corrosion","Cold-end corrosion \u002F dew-point corrosion",[83,489,490],{},[64,491,492],{"href":120},"Tube erosion \u002F tube wastage",{"title":169,"searchDepth":170,"depth":170,"links":494},[495,496,497,498],{"id":409,"depth":170,"text":410},{"id":416,"depth":170,"text":417},{"id":436,"depth":170,"text":437},{"id":142,"depth":170,"text":143},"Chloride-induced corrosion is the accelerated tube-wall thinning caused by chlorine-rich deposits on the steam-side surfaces of WtE, biomass and waste-fired boilers. Chloride corrosion is the dominant tube-failure mechanism in WtE and a major maintenance cost driver.",{},[213,182,184,502,503],"cold-end-corrosion-dew-point-corrosion","tube-erosion-tube-wastage",{"title":505,"description":506},"Chloride-induced corrosion — accelerated tube wastage in WtE and biomass boilers","Chloride-induced corrosion is the accelerated tube-wall thinning caused by chlorine-rich deposits on WtE and biomass boilers. The dominant tube-failure mechanism in WtE.",[508],{"title":509,"url":510},"npj Materials Degradation — Low-temperature corrosion in biomass boilers","https:\u002F\u002Fwww.nature.com\u002Farticles\u002Fs41529-025-00640-4","glossary\u002Fchloride-induced-corrosion","PVL_lGkefdByes5ldZdrOSzMPRd3dW-6jJv-GqlhciY",{"id":514,"title":161,"aliases":515,"body":519,"category":175,"description":617,"extension":177,"meta":618,"navigation":179,"path":107,"relatedTerms":619,"seo":621,"sources":624,"stem":626,"term":161,"__hash__":627},"glossary\u002Fglossary\u002Flow-melt-sticky-ash.md",[516,517,518],"sticky ash","low-melting ash","alkali-rich sticky ash",{"type":53,"value":520,"toc":611},[521,535,539,547,551,561,563,584,586],[56,522,523,525,526,328,528,530,531,534],{},[59,524,161],{}," is the universal headache of ",[64,527,405],{"href":212},[64,529,213],{"href":212}," boiler operation. It forms when ash particles rich in ",[64,532,533],{"href":150},"alkali metals"," (K, Na) and chlorides soften at typical convective-pass gas temperatures (700–900 °C) and bond to cooler tube surfaces on contact.",[75,536,538],{"id":537},"why-it-defeats-steam-sootblowers","Why it defeats steam sootblowers",[56,540,541,542,546],{},"A steam jet from an ",[64,543,545],{"href":544},"\u002Fglossary\u002Fik-long-retract-sootblower","IK retract sootblower"," is highly effective on dry, friable ash but largely ineffective on a deposit that has bonded as a continuous sticky film. The steam removes only the loose surface layer; the bonded under-layer remains and continues to grow.",[75,548,550],{"id":549},"why-sonic-horns-help","Why sonic horns help",[56,552,553,555,556,560],{},[64,554,133],{"href":132}," work ",[557,558,559],"em",{},"before"," the deposit consolidates. Continuous low-amplitude vibration during the early sticky phase prevents the deposit from forming a bonded interface with the tube. The ash remains friable enough to be released by sootblowers or by the next horn pulse, rather than building up into a self-reinforcing sticky mass.",[75,562,417],{"id":416},[80,564,565,572,578,581],{},[83,566,567,568],{},"Recovery boilers — see ",[64,569,571],{"href":570},"\u002Fglossary\u002Fcarry-over","carry-over",[83,573,574,577],{},[64,575,576],{"href":180},"Straw"," and high-alkali biomass",[83,579,580],{},"WtE boilers, especially with high-RDF feed",[83,582,583],{},"Petcoke firing in some configurations",[75,585,143],{"id":142},[80,587,588,592,596,600,606],{},[83,589,590],{},[64,591,151],{"href":150},[83,593,594],{},[64,595,156],{"href":97},[83,597,598],{},[64,599,473],{"href":212},[83,601,602],{},[64,603,605],{"href":604},"\u002Fglossary\u002Fsuperheater","Superheater",[83,607,608],{},[64,609,610],{"href":132},"Sonic horn",{"title":169,"searchDepth":170,"depth":170,"links":612},[613,614,615,616],{"id":537,"depth":170,"text":538},{"id":549,"depth":170,"text":550},{"id":416,"depth":170,"text":417},{"id":142,"depth":170,"text":143},"Low-melt sticky ash is the universal headache of biomass and waste-to-energy boiler operation. It forms when ash particles rich in alkali metals (K, Na) and chlorides soften at typical convective-pass gas temperatures (700–900 °C) and bond to cooler tube surfaces on contact.",{},[182,183,213,620,339],"superheater",{"title":622,"description":623},"Low-melt sticky ash — the universal headache of biomass and WtE cleaning","Low-melt sticky ash forms when alkali-rich ash particles soften at typical convective-pass temperatures and bond to tube surfaces. Defeats steam sootblowers; primary target for sonic horns.",[625],{"title":383,"url":384},"glossary\u002Flow-melt-sticky-ash","T-fxgBz2Ckq6-Jqq1LywnOSrLjgAelnaRUCmw8i4qQA",{"id":629,"title":167,"aliases":630,"body":634,"category":185,"description":842,"extension":177,"meta":843,"navigation":179,"path":166,"relatedTerms":844,"seo":851,"sources":854,"stem":861,"term":167,"__hash__":862},"glossary\u002Fglossary\u002Fboiler.md",[631,632,633],"industrial boiler","utility boiler","steam generator",{"type":53,"value":635,"toc":837},[636,658,662,771,775,806,808],[56,637,638,639,641,642,402,644,328,646,650,651,328,654,657],{},"A ",[59,640,185],{}," is a closed vessel in which fuel chemical energy is converted to steam by transferring heat into water flowing through tube banks. Industrial and utility boilers serve electricity generation, district heating, process steam, ",[64,643,401],{"href":212},[64,645,405],{"href":212},[64,647,649],{"href":648},"\u002Fglossary\u002Frecovery-boiler","pulp-and-paper"," operations. All of them foul; the only variables are ",[557,652,653],{},"how much",[557,655,656],{},"with what",".",[75,659,661],{"id":660},"boiler-families","Boiler families",[220,663,664,676],{},[223,665,666],{},[226,667,668,671,673],{},[229,669,670],{},"Type",[229,672,231],{},[229,674,675],{},"Notes",[236,677,678,692,705,718,731,745,756],{},[226,679,680,686,689],{},[241,681,682],{},[64,683,685],{"href":684},"\u002Fglossary\u002Fpc-boiler","PC boiler",[241,687,688],{},"Pulverised coal",[241,690,691],{},"Dominant utility design",[226,693,694,699,702],{},[241,695,696],{},[64,697,698],{"href":71},"CFB boiler",[241,700,701],{},"Coal, biomass, RDF, lignite",[241,703,704],{},"Tolerates wider fuel range; lower NOx",[226,706,707,712,715],{},[241,708,709],{},[64,710,711],{"href":66},"BFB boiler",[241,713,714],{},"Biomass, sludge, low-grade fuels",[241,716,717],{},"Bubbling fluidised bed",[226,719,720,725,728],{},[241,721,722],{},[64,723,724],{"href":648},"Recovery boiler",[241,726,727],{},"Black liquor (kraft pulp mills)",[241,729,730],{},"Combines chemicals recovery with steam",[226,732,733,739,742],{},[241,734,735],{},[64,736,738],{"href":737},"\u002Fglossary\u002Fhog-fuel-boiler-bark-boiler","Hog-fuel boiler",[241,740,741],{},"Wood waste, bark",[241,743,744],{},"Common at pulp mills as side boilers",[226,746,747,750,753],{},[241,748,749],{},"Gas \u002F oil boiler",[241,751,752],{},"Natural gas, fuel oil",[241,754,755],{},"Lower particulate, less fouling",[226,757,758,761,764],{},[241,759,760],{},"HRSG",[241,762,763],{},"Gas-turbine exhaust",[241,765,766,767],{},"See ",[64,768,770],{"href":769},"\u002Fglossary\u002Fheat-recovery-steam-generator","heat-recovery steam generator",[75,772,774],{"id":773},"where-sonic-horns-sit","Where sonic horns sit",[56,776,777,779,780,402,784,402,787,328,791,795,796,800,801,805],{},[64,778,133],{"href":132}," installed across the convective pass — between ",[64,781,783],{"href":782},"\u002Fglossary\u002Feconomiser","economiser",[64,785,786],{"href":604},"superheaters",[64,788,790],{"href":789},"\u002Fglossary\u002Freheater","reheater",[64,792,794],{"href":793},"\u002Fglossary\u002Fair-heater","air heater"," — dislodge ash and soot continuously, supplementing or partially replacing steam ",[64,797,799],{"href":798},"\u002Fglossary\u002Fsteam-sootblower","sootblowers",". The benefit shows up as ",[64,802,804],{"href":803},"\u002Fglossary\u002Fheat-rate","heat rate"," recovery, deferred outages and longer intervals between water washes.",[75,807,143],{"id":142},[80,809,810,814,818,822,828,833],{},[83,811,812],{},[64,813,685],{"href":684},[83,815,816],{},[64,817,698],{"href":71},[83,819,820],{},[64,821,724],{"href":648},[83,823,824],{},[64,825,827],{"href":826},"\u002Fglossary\u002Fwaterwall","Waterwall",[83,829,830],{},[64,831,832],{"href":782},"Economiser",[83,834,835],{},[64,836,610],{"href":132},{"title":169,"searchDepth":170,"depth":170,"links":838},[839,840,841],{"id":660,"depth":170,"text":661},{"id":773,"depth":170,"text":774},{"id":142,"depth":170,"text":143},"A boiler is a closed vessel in which fuel chemical energy is converted to steam by transferring heat into water flowing through tube banks. Industrial and utility boilers serve electricity generation, district heating, process steam, WtE, biomass and pulp-and-paper operations. All of them foul; the only variables are how much and with what.",{},[845,846,847,848,849,783,620,850,339],"pc-boiler","cfb-boiler","bfb-boiler","recovery-boiler","waterwall","air-heater",{"title":852,"description":853},"Boiler — industrial steam generator types and acoustic-cleaning needs","A boiler is a vessel that converts fuel chemical energy into steam by heating water. Coal-fired, biomass, oil, gas and recovery boilers all foul; sonic horns clean heat-transfer surfaces.",[855,858],{"title":856,"url":857},"Wikipedia — Boiler","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FBoiler",{"title":859,"url":860},"Babcock & Wilcox — Sootblower and Boiler Cleaning Terminology","https:\u002F\u002Fwww.babcock.com\u002Fhome\u002Fabout\u002Fresources\u002Flearning-center\u002Fsootblower-and-boiler-cleaning-terminology-principles-and-applications","glossary\u002Fboiler","pamAnZGo_UeIedDHhYrfv0nP3GCXkNTGi0a197n4b5Q",1782613760418]