The East Landfill Gas Utilization Project is an excellent example of the “direct use” of landfill gas as an energy source in another industrial operation. A direct-use project tends to be simpler to implement and more cost effective than typical power generation facilities where landfill gas is combusted in a prime mover (reciprocating engine or gas turbine) to generate power to supply to the grid. They also tend to more efficient than prime movers (likely 25 per cent or less) and displace traditional fossil fuels used in industrial boilers to generate steam.
The partners in this project consist of Integrated Gas Recovery Services Inc. (IGRS — Canada’s only full service design/build/ own/operate landfill gas utilization company), Abitibi-Bowater Inc., Niagara Waste Systems Ltd. (a Walker Industries company) in Niagara Falls, Ontario, and Enbridge Gas Distribution Inc., owner of the pipeline.
IGRS is itself a joint venture between Cambridge, Ontario-based Comcor Environmental Ltd. and Integrated Municipal Services Inc. (IMS) of Niagara Falls (another Walker company). Comcor provides landfill gas collection and operations expertise while IMS provides construction management and financing. The IGRS partnership also owns and operates the landfill gas utilization systems at the Britannia Landfill in Peel Region (5.2 MW) and the Trail Rd landfill in Ottawa (5 MW). IGRS is also currently designing systems for the Essex Windsor Solid Waste Authority and the Lafleche Environmental Inc. landfill near Ottawa, for installation later in 2008-2009.
Landfill gas is collected by 64 wells and 35 leachate manhole connections in the landfill. This covers approximately 60 per cent of the current landfill area and will be completed in 2010.
Gas is processed and transmitted down a 4,000 metre pipeline that feeds two of Abitibi-Bowater’s boilers, which burn a mixture of landfill gas and natural gas. The boilers are used to generate steam for Abitibi- Bowater’s Thorold mill — the largest 100 per cent recycled paper pulp mill in Canada and the outlet for a large percentage of the blue-box collected fibre in Ontario and the northeastern seaboard of the US.
The system has been installed in three phases, starting in 2001. In the last three years, the plant has consistently provided approximately 2,500 scfm of landfill gas at around 50 per cent methane (three million cubic metres per month) and displaces approximately 33 per cent of Abitibi-Bowater’s natural gas requirements.
The Niagara Waste Systems East Landfill has accepted mainly IC&I waste from the Niagara and GTA market since 1982. Landfill gas was never much of a concern in the early years, since much of the waste comes from industrial streams. Over the years the percentage of putrescable waste at the site rose. The first phase of the project was installed as a simple leachate manhole collection and flaring system, designed principally to deal with odour concerns. It was expanded over the years to include a vertical (drilled) well collection system and the pipeline to Abitibi-Bowater.
Rotary vane compressors in the landfill gas plant (at the south end of the site) provide the system vacuum that extracts gas from the landfill. The gas is filtered, dried and compressed prior to being transported down the pipeline. The gas quality is monitored at the plant for methane and oxygen content. High oxygen levels indicate that the collection system may be drawing too much air through the landfill cover, in which case system adjustments are needed. This balancing of the wellfield is the so called “art” of landfill gas collection. It is this author’s opinion that a successful system is best achieved where the landfill operations, landfill gas collection, processing and utilization are all controlled by one entity, thus aligning the priorities and maximizing gas production.
Under the project’s contractual arrangements, Abitibi-Bowater purchases gas from IGRS at a significant discount over natural gas and Niagara Waste Systems gets a robust landfill gas collection system that controls odours, provides a monthly gas royalty payment, while not incurring maintenance costs for the system. IGRS sells the gas and also augments the revenue from the system with three emission reduction credit (ERC) arrangements.
Niagara Waste Systems has recently received approval from the provincial environment ministry for a new waste disposal site (the South Landfill) adjacent to the East Landfill site. Both sites are mined-out limestone quarries. (The South site is still active.) The East Landfill site has a simple clay liner and leachate underdrain system. The new South Landfill will feature a double composite generic liner design. Landfill gas collection will be augmented by horizontal collectors as well as traditional vertical wells and leachate manhole connections. This expansion provides IGRS the opportunity to provide Abitibi- Bowater in the longer term with in excess of 7,500 cfm of gas (three times the current flow), essentially eliminating the mill’s dependence on natural gas.
A 2007 expansion of the system (19 new extraction wells and seven new manhole connections) included the installation of additional compression capacity and a one-megawatt Jenbacher reciprocating engine that provides consistent renewable energy to the grid in partnership with St Catharines Hydro Generation Inc. This has been in operation since December 18, 2007 and has a Standard Offer contract with the Ontario Power Authority (OPA). A second pipeline to Abitibi-Bowater is being installed and is set for April 2008 completion. This will provide the opportunity to send approximately another 900 cfm to the mill by June of this year.
What have we learned?
This project has delivered four important lessons about success in this area:
1. Redundancy:We are now in the utility business, so all critical components must have a backup. Strategic investments have been made since the projects inception to maximize plant “up-time” — averaging 92 per cent annually.
2. Communication: Our customer needs to know exactly what is going on at our plant and vice versa. Unplanned shutdowns at either end of the pipeline benefit no one. All of IGRS plant operating parameters can be accessed over the internet and critical adjustments can be made from a distance if needed.
3. Wellfield Monitoring: Having highly trained staff “fine tune” the wellfield and vacuum in different parts of the system maximizes gas quality and quantity, and minimizes odors.
4. Patience: These are large, complex projects with many stakeholders. Stakeholder management is critical at all phases (feasibility, partner assembly, design, construction and operations).
Mike Watt, P. Eng., is VP Walker Environmental Group and Director, Integrated Gas Recovery Services Inc. in Thorold, Ontario. Contact Mike at email@example.com