Mayor's Report - November 2007

In September I reported on the region’s Zero Waste Challenge and the fact that Metro Vancouver’s residents and businesses generate over 3 million tonnes of garbage and recyclables each year. The economic and environmental costs of handling these vast amounts of solid waste are an increasing technical challenge for all residents of the region.

Waste-to-energy (WTE) is a critical component of Europe's waste disposal strategy, and the City of Amsterdam is using 4^th generation WTE technology. For Metro Vancouver WTE is already an important element of the region’s Solid Waste Management Strategy, but it now needs to be expanded. The Burnaby WTE facility currently consumes 800 tonnes of solid waste per day (280,000 tonnes per year), and produces 15 MW of electricity (enough for 15,000 homes) that is fed back to the regional grid. The Burnaby WTE facility annually generates $10 million in electricity sales and $6 million in steam sales.

A global overview of WTE recently presented to the region’s Waste Management Committee made the following key points:

What WTE is NOT:

• It is not an excuse to “waste” --- we must encourage the 3R’s before we move to the 4^th R --- Recovery of Energy;
• It is not reuse to energy --- glass acts as a heat sink;
• It is not recyclables to energy;
• It is not the answer to all our problems in disposal and not a 100% replacement of landfills.

What WTE IS:

• An effective method of residuals disposal and recovery of energy --- 90% volume reduction and firm electrical and heat production;
• Has a proven track record of environmental performance --- better than burning natural gas;
• A renewable source of energy, a sensible fuel --- an alternative to burning virgin fossil fuels;
• A major part of an integrated Solid Waste Management Plan;
• A local benefit for environmentally safe and secure waste disposal, and energy/heat generation.

A Life Cycle Assessment (LCA) which evaluates the life-cycle environmental burdens of WTE compared to Landfilling of solid waste leads to the following conclusions:

• Transportation emissions are relatively minor;
• WTE recovers almost five times more electricity and heat than Landfilling;
• GHG emissions are 370 kg CO₂ e/t MSW for Landfilling and 290 kg CO₂ e/t MSW for WTE;
  (MSW = Municipal Solid Waste)
• Landfilling produces higher emissions of NO_x, PM₁₀, and CO (due to cogeneration and flaring of landfill gas); SO_x emissions are similar for both approaches.

I recently received a thoughtful five-page commentary from Walter Mechler, a Farrer Cove resident and retired waste management engineer, on the Greenhouse Gas (GHG) implications of solid waste management that he submitted to the province under the BC Budget Consultation Process. Walter’s well-researched analysis prompted me to request further information on the subject from Metro Vancouver’s engineering group. From Metro Vancouver’s perspective, the following key points need to be considered:

GHG Emissions From Landfills

According to the BC Ministry of Environment, 19 percent of GHG emissions on a per household basis are contributed by household waste, a good portion of which is attributable to the fugitive emission of methane gas generated by household waste disposed in landfills. This is second only to personal vehicle use (40 percent) and equal to air travel (also 19 percent). As a GHG, methane is 21 times more potent than carbon dioxide. Despite best efforts to capture methane gas in landfills and use it beneficially, there still can be relatively inefficient lifetime capture rates. Metro Vancouver’s assumptions are based on the research and recommendations of the US Environmental Protection Agency (USEPA), which indicate that best capture rates are unlikely to exceed much more than 75 percent. In general, if the goal is to generate and capture methane gas from biomass for beneficial use, then a landfill, even a bioreactor landfill, is a very inefficient “machine”. Different calculations based on ‘reasonable’ assumptions indicate that for every tonne of municipal solid waste 100-200 kilowatt hours of electricity could be generated from landfill gas, whereas 650 kilowatt hours of electricity could be generated in a waste-to-energy plant. In other words, waste-to-energy plants are 3 to 6 times more effective than landfills when it comes to energy production.

Requiring capture and use, or flaring, of landfill gas is certainly an important step, but, as the European Commission has already established, keeping untreated organic waste out of landfills is a much better long-term management strategy to address the fugitive methane issue and its resulting GHG contribution. A long-term strategy to eliminate the deposition of raw, unprocessed waste in landfills will halt the trend of increased GHG emissions from landfills. This will likely be made a key strategy in Metro Vancouver’s updated Solid Waste Management Plan to help advance the goal, now firmly established by the province, of reducing GHG’s.

Mechanical Biological Treatment (MBT)

There are many combinations of mechanical and biological processes that can be combined into the so-called Mechanical Biological Treatment (MBT) process. They all typically involve a sorting facility in combination with a form of biological treatment, such as composting or anaerobic digestion, to process mixed household waste. Some form of Material Recovery Facility (MRF) performs the sorting, which can result in a Refuse Derived Fuel (RDF). Edmonton’s facility is a good example of MBT in Western Canada.

Mr. Mechler refers to the varying successes associated with these types of facilities. He also refers to the 2005 report from the British consulting firm Jupiter Consultancy Services Ltd. The conclusions outlined in the executive summary of that report highlight some of the challenges associated with the outputs from these plants --- notably poor quality compost and marginal fuel that may have limited markets. The markets for the end products require careful assessment when considering these types of facilities. The limited markets for Metro Vancouver’s own treatment plant biosolids --- the end product of a biological treatment process --- is a good example of this problem.

Refuse Derived Fuel (RDF) requires energy to manufacture. Again, Metro Vancouver’s studies indicate that for every tonne of municipal solid waste 570 kilowatt hours of electricity could be generated from a good quality RDF compared to 650 kilowatt hours when processed at a waste-to-energy facility.

MBT is useful to keep raw, unprocessed waste out of landfills, but has its complexities and issues.

Waste-to-Energy (WTE)

Waste-to-energy provides the most direct way to transform residual mixed waste into electricity. Metro Vancouver has written to the province identifying the need to establish the biomass to fossil fuel proportion for municipal solid waste that will be considered when calculating GHG emissions in BC. This will be important relative to the GHG reduction calculations and the potential credits, which could be used in future emissions trading systems. Metro Vancouver’s current estimates are that the biomass to fossil fuel proportion is about 60/40. Regardless, many US states have already accepted waste-to-energy plants as equivalent to renewable power (wind, hydro, solar, etc.) based on the high proportion of biomass and the fact that recovery of the fossil fuel portion in the waste avoids, or offsets, the burning of virgin fossil fuels in power plants. Metro Vancouver would like to see BC accept waste-to-energy as renewable power.

It is Mr. Mechler’s assessment that WTE is a reliable source of base-load electrical power. More importantly for Metro Vancouver, it is base-load power that can be generated within the region. Mr. Mechler also points out that the fossil fuel portion in the waste avoids the extraction of virgin fossil fuel. The benefit of recovering this energy value from the waste, rather than simply disposing the material in a landfill, is in keeping with the Waste Hierarchy Principle (reduce-reuse-recycle-recover-manage residuals). This is becoming increasingly relevant given the need to find new sources of reliable base-load power in BC and the need to reduce GHG. Further advantages are gained by utilizing the waste heat from WTE facilities to offset space heating using fossil fuels or industrial heating requirements that would otherwise require the burning of fossil fuels.

In Summary:

• Continuing to dispose raw, unprocessed solid waste in landfills will only perpetuate the GHG emissions from landfills due to the escape of fugitive methane gas.
• Mechanical Biological Treatment (MBT) processes can keep unprocessed waste out of landfills, but these processes have issues related to technical complexity and the quality of end products.
• Waste-to-energy facilities are able to process residual quantities of mixed solid waste and provide a reliable source of base-load electricity and heat by directly utilizing the biomass and non-virgin fossil fuel available in the mixed waste.

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