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Landfill Gas 101

Landfill Gas 101. HALTON REGION Public Works - Waste Management Services May 15, 2014 – MWA Spring Workshop, Hockley Valley Resort Presented by: Art Mercer, Supervisor of Landfill Operations. Today’s Topics. Background on Halton Region Sources of Methane

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Landfill Gas 101

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  1. Landfill Gas 101 HALTON REGION Public Works - Waste Management Services May 15, 2014 – MWA Spring Workshop, Hockley Valley Resort Presented by: Art Mercer, Supervisor of Landfill Operations

  2. Today’s Topics • Background on Halton Region • Sources of Methane • The How, What & Why of Landfill Gas (LFG) Systems • Development of Halton’s LFG Collection, Flaring & Utilization System • Gas Collection Components • Utilization Facility Components • Project Costs and Results • Lessons Learned

  3. Halton Region Population ~ 525,000 On Lake Ontario between Toronto & Hamilton 4 Local Municipalities : Burlington, Halton Hills, Milton & Oakville Landfill ~ 75,000 tonnes of garbage per year Remaining site life is until 2044 at current fill rates The Halton Waste Management Site is located in Milton, Ontario

  4. Major Sources of Methane Emissions… Agriculture Globally, domestic livestock are the primary source of methane which is produced as part of their normal digestive process Environment Canada(2013)

  5. Major Sources of Methane Emissions… Environment Canada(2013)

  6. Major Sources of Methane Emissions… Landfills • Anaerobic decomposition of buried organic waste produces landfill gas • Landfill gas is composed primarily of methane (CH4 ) and carbon dioxide (CO2) which are greenhouse gases • CH4 has 21-times the global warming potential of CO2 * • Canadian landfills account for 20% of national methane emissions * * Environment Canada(2013)

  7. How do you capture Landfill Gas? Use vacuum pressure within the landfill to collect the LFG before it escapes to the atmosphere What can you do with captured Landfill Gas? Flare it to destroy the methane (good choice) Use the combustion energy for power generation instead (better option) Why collect Landfill Gas at all? GHG emissions reductions for landfills Offset use of non-renewable fossil fuels (if utilized for electricity generation) Reduce odours and potential for off-site impacts Regulations now make it mandatory to collect LFG in Ontario (2010) The How, What & Why of Landfill Gas Systems

  8. Development of the Halton Landfill Gas Collection, Flaring & Utilization System Phase 1 COLLECTION FACILITY - (Constructed 2006) • Halton Region installed wells within landfill and constructed a flare station • Landfill gases were then vacuumed from the landfill to the enclosed flaring system for burning Phase 2UTILIZATION FACILITY - (Constructed 2007) • Partnership was struck between Halton Region and Oakville Hydro in 2004 for development • Oakville Hydro installed two 1-Megawatt engines (GE-Jenbacher) running exclusively on LFG captured and provided by Halton Region in 2007 • Facility has capacity to generate enough “green power” to provide electricity for up to 1,500 homes (2-MW) • Electricity is sold to Ontario Power Authority under purchase agreement with Oakville Hydro and distributed by the local utility, Milton Hydro

  9. Gas Collection Components (Phase 1) 1) Vertical Wells – installed in deep waste in closed landfill areas 2) Horizontal Collection Trenches – Installed within waste during filling 3) Headers & Laterals – Transmit gas from landfill to Blower Building 4) Condensate Sumps – Collect moisture along header pathways

  10. Gas Collection Components Vertical Extraction Wells • Wells are drilled into waste • Consist of perforated vertical piping surrounded by porous granular materials • Well-head allows volume of gas extracted to be regulated • Applying vacuum pressure to the well creates a collection “zone-of-influence” of up to 30 metre radius • Wells are spaced out to achieve full coverage for optimal capture of the landfill gases

  11. Gas Collection Components

  12. Gas Extraction Hardware Perforated horizontal collection pipe installed in waste

  13. Gas Extraction Hardware Solid-walled Lateral piping

  14. Gas Extraction Hardware Solid-walled large diameter perimeter Main Header piping

  15. Gas Extraction Hardware Condensate sump riser with internal pump and buried discharge

  16. Collection meets Utilization

  17. Components Condensate Trap Moisture Separator Condenser-Chiller Loop Blowers Main Flare (Enclosed) Gas Treatment (Carbon Filter) Purge Flare (Candle-stick) Generators “Make the Green Power” Utilization Facility Components

  18. Project Costs and Results • Halton’s LFG collection system required initial investment of $3.4-Million in 2006 for 21-Vertical Wells, 5-Horizontal Collection Pipes, Blowers, Flare and peripherals • Two well-field expansions of $0.25-M (2009) and $0.75-M (2013). System now consists of 80 gas collection points • Oakville Hydro invested $4.1-Million to construct the power generation facility in 2007, includes two 1-MW gen-sets and peripheral equipment • Currently collecting 250 – 500 cubic feet per minute of LFG (varies seasonally) • 99% of LFG collected is utilized for power production on site, generating revenue through OPA standard offer program (2007) • Halton Region achieved voluntary early-action acknowledgement for compliance with a 2010 Regulation 347 Amendment requiring all landfill’s containing > 1.5-million m3 of waste to have a LFG collection system installed

  19. Lessons Learned • Differing requirements for Collection and Utilization can create challenges, e.g.volume of gas for environmental controls –vs- power generation/revenue • Revenue sharing plans (contracts) should be targeted to provide sufficient income to cover operating costs for all partners • Horizontal collection piping is subject to flooding from perched leachate conditions which “choke off” the gas flow, therefore are not recommended for this climate • Vertical wells can also partially fill with liquid. Pumping it out improves gas capture, although this does increase costs of collection

  20. Lessons Learned (Cont’d) • Scrutiny of collection system designs before construction can help reduce operational issues such as unnecessary Confined Spaces and other H&S issues (e.g. in-ground chambers for well heads, chambers for condensate sumps) • Study of waste composition, density and moisture content can help to maximize gas capture and improve well field design • Due to the variability of landfill factors, need to ensure that experienced consultants and operators are hired who are familiar with unique design and operation challenges of LFG systems

  21. Contact THANK YOU! QUESTIONS? Art Mercer, Supervisor of Landfill Operations 905-825-6000 x 8207, art.mercer@halton.ca

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