landfill gas management
DESCRIPTION
management of landfill gas presenationTRANSCRIPT
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2/3/2010
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas ManagementLandfill Gas Management Overview
Landfill gas generation Landfill gas migration Landfill gas management systems
Containment Collection Treatment Energy recovery
Construction Operations
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Stages of Gas Generation
I AerobicII Anaerobic, non-methanogenic (acid anerobic)III Anaerobic, methanogenic, unsteadyIV Anaerobic, methanogenic, steady
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Stoichiometric Estimate of Potential
( )( ) ( ) 342
2
32481324
81
32441
cNHCHcbaCOcba
OHcbaNOCH cba
+++++
++
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Gas Potentials
3 - 90 L/kg dry
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Biochemical Methane Potential
Sample Methane Yield, m3/kg VS
Mixed MSW 0.186 - 0.222
Mixed Yard Waste 0.143
Office Paper 0.369
Newsprint 0.084
Magazine 0.203
Food Board 0.343
Milk Carton 0.318
Wax Paper 0.341*From Owens, J.M. and D.P. Chynoweth
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Problems with Stoichiometric Estimates
Some fractions are not biodegradable (lignin, plastics)
Moisture limitations Toxins Some fractions are not accessible (plastic
bags)
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Estimates of Gas Production Rates
Rapid degradation conditions: 3 to 7 years (4 to 10 L/kg/yr)
Moderate degradation conditions: 10 to 20 years (1.5 t 3 L/kg/yr)
Slow degradation conditions: 20 to 40 years (0.7 to 1.5 L/kg/yr)
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Gas Enhancement Techniques Moisture Content Shredding Leachate Recycle Inoculum Addition Buffer Nutrient Addition Temperature
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Gas Composition - Major Gases Methane (45 - 60 % by volume) Carbon Dioxide (40 - 60 % by volume) Nitrogen (2 - 5 % by volume) Oxygen (0.1 - 1.0 % by volume) Ammonia (0.1 - 1.0 % by volume) Hydrogen (0 - 0.2% by volume)
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Gas Composition - Trace Gases (less than 0.6 % by volume)
Odor causing compounds Aromatic hydrocarbons Chlorinated solvents Aliphatic hydrocarbons Alcohols Polyaromatic hydrocarbons
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Why Bother with Landfill Gas? Odor Toxics Greenhouse Gas Explosive Gas
Potential Energy Source
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas ManagementLandfill Gas Management Containment
Natural barriers High groundwater table Streams/Waterbodies tied to groundwater Impermeable geologic strata
Manmade barriers Composite liner Composite cover Cutoff walls Negative pressure trenches Positive pressure systems (Brewers Stadium)
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas ManagementLandfill Gas Management Landfill Gas Collection Systems
Components Gas extraction wells or trenches Gas extraction well heads Gas header pipes Condensate management Drip legs Condensate knockouts Control valves Blower station Flare (open or closed)
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Components of Gas Recovery System
One or more wells placed within the refuse A header system to connect the wells to the gas
pumphouse system creating the suction A flare system providing the opportunity to combust
the landfill gas in the event that the gas is not needed An end user of the gas
Header system
Gas pumphouseFlare system
Recovery plant(end user)
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas ManagementLandfill Gas Management Landfill Gas Collection Systems
(continued) Objective of system
Migration control Regulatory compliance Energy recovery $ Listen to clients needs Always consider health and safety
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas ManagementLandfill Gas Management Landfill Gas Collection System Design
Steps Consider objectives Define limits of landfill
Horizontally and vertically Gas extraction wells or trenches Layout gas wells
Shallow wells - small ROI Deep wells - large ROI Typically 150 ROI (per NR 500) Liquid levels in landfill
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas ManagementLandfill Gas Management Landfill Gas Collection System
Design Steps (continued) Locate gas header pipe Establish condensate management Adjust gas wells, if needed Prepare a well schedule (example)
0.5 to 1.5 cfm/slotted foot of pipe Determine gas generation and flow
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas ManagementLandfill Gas Management Landfill Gas Collection System Design
Steps (continued) Header and blower sizing calculations
Calculate by hand Spreadsheet Computer model KY GAS (Hardy cross method)
Condensate calculations Select blower flare system
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas ManagementLandfill Gas Management Rules of Thumb for Header Design
A velocity of 50 feet per second is the maximum allowed during concurrent flow conditions
A velocity of 30 feet per second is the maximum allowed during countercurrent flow conditions
A velocity of 30 feet per second is the maximum allowed within condensate management structures
A pressure drop of 1 inch water column per 100 feet of header is the maximum allowed under any flow conditions
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas ManagementLandfill Gas Management Rules of Thumb for Header Design
(continued) Flow conditions within a header must not
exceed either pressure loss nor velocity limitations
10 inches of vacuum required at furthest extraction well
10 to 20 inch loss of vacuum at blower flare station
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas Migration -Wells
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas Migration -Trench
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Passive Systems
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Passive Landfill Gas ControlLANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas Control
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Landfill Gas is Typically Extracted to a Blower-Flare Station
Landfill
Note:Must Drain
Condensate
BlowerFlare
Station
Gas Wells
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Gas Extraction Wells Vertical piping system: installed following the refuse
placement Horizontal piping system: installed as the refuse is
placed Design considerations
Spacing: zone of influence - apparent zone of vacuum influence around a well
Location: site topography, age of refuse, and system expansion over time
Depth: refuse depth, leachate mound, and cell construction
Factors affecting performance of gas extraction system Daily cover Elevated or perched liquids Shallow depth
Sludge or liquid depth Permeability of final cover
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Waste
Cap
Gas Extraction Pipe
GravelPack
PerforatedPVC Pipe
WellHead
Passive Wells (wells open to atmosphere) Active Wells (wells connected to a gas extraction
system).LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Vertical Piping System
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Equilateral Triangular Distribution
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Types of Collection WellsVertical wells
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Condensate collection and Pump Station
Landfill gas condensate as gas cools while it is transported through the gas collection system a liquid is formed (cutting of vacuum to the wells), separated from gas flow and collected in the low spots of the system
Pumping station reservoir condensate forced to drain into it from low spots
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
Gas Treatment Methods Gas flaring controlled combustion unit,
reduces odors and more environmentally sound than passive venting, enclose flares more efficient than open flares
Gas processing and energy recovery gas processed by removing water, carbon dioxide, and other impurities
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LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
)
CH4 converted to CO2during passage through Bio CoverRecovery of
CH4 for energygeneration
4 2CH & CO LateralMigration
Oxidation of Methane in Landfill Bio Cover(by Methanotrophs)
LANDFILL GAS MANAGEMENT
Dr.Kurian Joseph, Centre for Environmental Studies, Anna University, Chennai 600 025; E mail : [email protected]
0 2
)
)
)
CH4 + 2O2 CO2 + 2H2O + Cells
CHON CH4 + CO2 + Cells
Methanotrophs
Methanogens
Atmosphere
Barrier
Emission
Waste layer(CH4 generation)
Cover soil(CH4 oxidation)
Methane and carbon dioxideare the major greenhouse gases produced in landfill
Methane gas can be utilized as energy source in large landfills, but it should be eliminated when its utilization is not feasible especiallyin small landfill
Methane oxidation: Low costoption for reducing methaneemission from landfill
Oxidation of Methane in Landfill Bio Cover(by Methanotrophs)
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LANDFILL GAS MANAGEMENT
Kurian Joseph, Centre for Environmental Studies,Anna University, Chennai -600 025 ; E mail:[email protected]
LAN
DFI
LL B
IOR
EACT
OR
Kurian Joseph, Centre for Environmental Studies,Anna University, Chennai -600 025 ; E mail:[email protected]
LANDFILL GAS MANAGEMENT
Kurian Joseph, Centre for Environmental Studies,Anna University, Chennai -600 025 ; E mail:[email protected]
Comparison of Biodegradation Time
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LANDFILL GAS MANAGEMENT
Kurian Joseph, Centre for Environmental Studies,Anna University, Chennai -600 025 ; E mail:[email protected]
BIOREACTOR LANDFILL TECHNOLOGY
Liquids must be added to the waste to obtain optimal moisture content, which ranges from 35 to 45 percent water by weight. Liquids that are added include: landfill leachate, gas condensate, water, storm water runoff, and wastewater treatment sludges.
LANDFILL GAS MANAGEMENT
Anaerobic Bioreactor
Liquids Storage
Gas Collection to Generate Energy
GroundwaterMonitoring
LAN
DFI
LL B
IOR
EACT
OR
Kurian Joseph, Centre for Environmental Studies,Anna University, Chennai -600 025 ; E mail:[email protected]
http://www.wastemanagement.com/Bioreactor.ppt