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Metodik för att förhindra metanemissioner från avfallsdeponier, tillämpad vid Albäcksdeponin, Trelleborg

Bjerg, Benjamin (2011) In Examensarbeten i geologi vid Lunds universitet
Department of Geology
Abstract (Swedish)
Gasbildning i deponier kan pågå under mycket lång tid, och bidrar i väsentlig grad till antro-pogena utsläpp av växthusgaser i form av metanemissioner. Det finns ett behov av att få bättre kännedom hur läckage av metan sker, och av miljö samt ekonomiska skäl, är det viktigt att samla in och återvinna metangas. Albäcks avfallsupplag i Trelleborg, har sedan årsskiftet 2008/2009 upphört efter mer än 50 års deponeringsverksamhet. Syftet med projektet var att ta fram information om gasläckage, mäta metanutsläpp från avfallsupplagsytor, och att utveckla en generell metodik för att minska metanläckage från deponier.

I projektet har ett handburet laserinstrument av typen ”LaserMethane Mini” använts för skanning efter läckagekällor.... (More)
Gasbildning i deponier kan pågå under mycket lång tid, och bidrar i väsentlig grad till antro-pogena utsläpp av växthusgaser i form av metanemissioner. Det finns ett behov av att få bättre kännedom hur läckage av metan sker, och av miljö samt ekonomiska skäl, är det viktigt att samla in och återvinna metangas. Albäcks avfallsupplag i Trelleborg, har sedan årsskiftet 2008/2009 upphört efter mer än 50 års deponeringsverksamhet. Syftet med projektet var att ta fram information om gasläckage, mäta metanutsläpp från avfallsupplagsytor, och att utveckla en generell metodik för att minska metanläckage från deponier.

I projektet har ett handburet laserinstrument av typen ”LaserMethane Mini” använts för skanning efter läckagekällor. Fältmätningar med laserinstrumentet kompletterades med borrningar, där prover togs för att analysera ytskiktets egenskaper, samt bestämma organisk halt av deponerat avfall. Borrningar utfördes i ett försök att finna ett samband mellan upptäckta läckagekällor och ytskiktets täthet, samt halten av nedbrutet organiskt material. Metanproduktion av deponerat avfall kan påverkas av tätare täckning, vilket ger torrare avfall med mindre gas-produktion, men även åldern på deponerat material är av betydelse.

Undersökningarna visar att läckage vid Albäcks avfallsupplag i första hand består av punktläckage, men även områden av diffust metanläckage över ytor med okänd läckagekälla. Det har även noterats att läckage ofta förekommer i anslutning till olika brunnar, gasledningar samt observationsrör. Flera punktkällor visar att metannivåer vid en tidpunkt kan vara mycket höga, för att vid nytt mättillfälle visa knappt mätbara värden. Ytor som visar större känslighet för metanläckage är slänt, släntkrön samt släntfot. Punktläckage visar sig ofta vara kopplat till områden med död vegetation eller kala regioner, samt sprickbildning i ytskiktet. Ytskiktets täckmaterial har visat sig vara av betydelse, där mäktigare lager i kombination med tätande finmaterial tydligt visat färre läckagekällor.

Inverkan av vinden vid mätning av metanemission är av stor vikt, där koncentrationen av metan kan öka eller sjunka med vindens styrka. Effekten av meterologiska faktorer som lufttryck på metanemissioner har inte kunnat påvisas från fältmätningarna. Baserat på väderdata som insamlats under mätningarna, har lufttrycket varierat mycket lite och kan möjligen vara orsaken till att inga slutsatser kan dras. Vid bestämning av organisk halt i deponin visar detta att det är generellt högre halter av föraskat kol från deponins yngre faser. Borrprover visade även att olika djup gav varierande viktförlust, vilket troligen beror på unika nedbrytningsmiljöer.
Genomförda tätningar vid utsatta punktläckage uppvisade goda resultat direkt efter första mätningarna, men återkontroll demonstrerade att flera tätade objekt blivit utsatta för oväntat höga påfrestningar. Några förändringar av uppsamlad deponigas efter utförda tätningar av större gasläckor, har inte kunnat påvisas, utan påverkar troligen endast lokalt tätat objekt genom minskat läckage. (Less)
Abstract
Gas formation in landfills may last for a very long time, and contributes significantly to anthropogenic emissions of greenhouse gases through emission of methane. Greater knowledge is needed about how methane leakage occurs and for environmental and economic reasons, it is important to collect and recycle methane gas. The Sysav landfill at Albäck in Trelleborg, has since the end of 2008/2009 been closed after more than 50 years of activity. The project aimed to provide information on gas leaks, measuring methane emissions from landfill surfaces and to develop a general methodology for reducing methane leakage from landfills.

In this project, a handheld laser instrument known as "LaserMethane Mini" was used to scan for leaks sources.... (More)
Gas formation in landfills may last for a very long time, and contributes significantly to anthropogenic emissions of greenhouse gases through emission of methane. Greater knowledge is needed about how methane leakage occurs and for environmental and economic reasons, it is important to collect and recycle methane gas. The Sysav landfill at Albäck in Trelleborg, has since the end of 2008/2009 been closed after more than 50 years of activity. The project aimed to provide information on gas leaks, measuring methane emissions from landfill surfaces and to develop a general methodology for reducing methane leakage from landfills.

In this project, a handheld laser instrument known as "LaserMethane Mini" was used to scan for leaks sources. Field measurements with the laser instrument were supplemented by screw drilling in which samples were taken to analyze the surface layer properties, and determine the organic content of landfill waste. The purpose of the drilling was done in an attempt to find a correlation between the detected leakage sources and surface layer density and concentration of decomposed organic materials. Methane production of landfill waste can be affected by thicker coverage and layer density, resulting in drier waste with less gas production, but also the age of the deposition material is relevant.
The results from field measurements indicated that leakage at Albäck landfill consists primarily of point source emission, but areas with diffuse methane leakage from surfaces have also been detected. It has also been noted that leakage occurs frequently in connection with different recovery wells, pipelines and observation wells. Several point source emissions show that the methane levels are not constant and, instead, can pulsate in intervals with maximum and minimum flows and in intervals with no measurable flow at all. Areas showing greater sensitivity to methane leakage are slopes, slope crests and slope toes. Gas leaks are often linked to areas of dead vegetation or bare regions, and visible cracks in the surface layer. Influence of landfill top layer has proven to be of importance when thickness and soil cover permeability are combined.

Results from field measurements indicated that wind speed and wind behaviour affect the level of the methane gas, where the concentration of methane could increase or decrease with wind speed. The effect of meteorological factors such as atmospheric pressure and methane emissions are correlated has not been possible to establish. Based on collected weather data, the air pressure varied little and could possibly be the reason that no conclusions can be drawn.

Determination of organic content shows that it is generally a higher content of combusted coal from younger cells. Drilling tests also showed that different depths gave varying weight losses, which is probably due to unique decomposition environments.
Completed seals at vulnerable point leakage, showed good results immediately after the first measurements, but later inspection demonstrated that several sealed objects have been exposed to unexpected high pressures. Any improvements in gas collection system at the landfill after sealed objects have not been able to establish. (Less)
Please use this url to cite or link to this publication:
author
Bjerg, Benjamin
supervisor
organization
alternative title
Methods to prevent methane emissions from landfills, applied at the landfill of Albäck, Trelleborg
year
type
H1 - Master's Degree (One Year)
subject
keywords
Lasermethane Mini, glödförlust, metangas, deponigasläckage, avfall, Trelleborg, Sysav, loss on ignition, methane gas, landfill gas leakage, waste
publication/series
Examensarbeten i geologi vid Lunds universitet
report number
277
language
Swedish
id
2278498
date added to LUP
2012-01-10 10:15:21
date last changed
2012-01-10 10:15:21
@misc{2278498,
  abstract     = {Gas formation in landfills may last for a very long time, and contributes significantly to anthropogenic emissions of greenhouse gases through emission of methane. Greater knowledge is needed about how methane leakage occurs and for environmental and economic reasons, it is important to collect and recycle methane gas. The Sysav landfill at Albäck in Trelleborg, has since the end of 2008/2009 been closed after more than 50 years of activity. The project aimed to provide information on gas leaks, measuring methane emissions from landfill surfaces and to develop a general methodology for reducing methane leakage from landfills.

In this project, a handheld laser instrument known as "LaserMethane Mini" was used to scan for leaks sources. Field measurements with the laser instrument were supplemented by screw drilling in which samples were taken to analyze the surface layer properties, and determine the organic content of landfill waste. The purpose of the drilling was done in an attempt to find a correlation between the detected leakage sources and surface layer density and concentration of decomposed organic materials. Methane production of landfill waste can be affected by thicker coverage and layer density, resulting in drier waste with less gas production, but also the age of the deposition material is relevant. 
The results from field measurements indicated that leakage at Albäck landfill consists primarily of point source emission, but areas with diffuse methane leakage from surfaces have also been detected. It has also been noted that leakage occurs frequently in connection with different recovery wells, pipelines and observation wells. Several point source emissions show that the methane levels are not constant and, instead, can pulsate in intervals with maximum and minimum flows and in intervals with no measurable flow at all. Areas showing greater sensitivity to methane leakage are slopes, slope crests and slope toes. Gas leaks are often linked to areas of dead vegetation or bare regions, and visible cracks in the surface layer. Influence of landfill top layer has proven to be of importance when thickness and soil cover permeability are combined. 

Results from field measurements indicated that wind speed and wind behaviour affect the level of the methane gas, where the concentration of methane could increase or decrease with wind speed. The effect of meteorological factors such as atmospheric pressure and methane emissions are correlated has not been possible to establish. Based on collected weather data, the air pressure varied little and could possibly be the reason that no conclusions can be drawn. 

Determination of organic content shows that it is generally a higher content of combusted coal from younger cells. Drilling tests also showed that different depths gave varying weight losses, which is probably due to unique decomposition environments. 
Completed seals at vulnerable point leakage, showed good results immediately after the first measurements, but later inspection demonstrated that several sealed objects have been exposed to unexpected high pressures. Any improvements in gas collection system at the landfill after sealed objects have not been able to establish.},
  author       = {Bjerg, Benjamin},
  keyword      = {Lasermethane Mini,glödförlust,metangas,deponigasläckage,avfall,Trelleborg,Sysav,loss on ignition,methane gas,landfill gas leakage,waste},
  language     = {swe},
  note         = {Student Paper},
  series       = {Examensarbeten i geologi vid Lunds universitet},
  title        = {Metodik för att förhindra metanemissioner från avfallsdeponier, tillämpad vid Albäcksdeponin, Trelleborg},
  year         = {2011},
}