City Council has approved a strategy to blend the renewable natural gas (RNG) that will be produced at Toronto’s organics processing facility with the natural gas that the City purchases to fuel vehicles and heat buildings. This will create a low-carbon fuel blend and allow the City to reduce greenhouse gas emissions across the organization.
The City of Toronto, in collaboration with Enbridge Gas Inc. (Enbridge), is installing biogas upgrading equipment at the Dufferin Solid Waste Management Facility. The infrastructure will allow the City and Enbridge to convert the biogas that is produced from processing Toronto’s Green Bin organic waste into renewable natural gas (RNG) and inject that gas into the natural gas distribution grid owned and operated by Enbridge. Once in the grid, the City can use the low-carbon fuel to power its waste collection trucks and other vehicles and/or heat City buildings and facilities.
This project is one of the first of its kind in Canada and North America and will allow the City to significantly reduce its greenhouse gas emissions. Current estimates suggest that the Dufferin RNG facility will produce approximately 3.3 million cubic metres of RNG per year.
The project supports the City’s Long Term Waste Management Strategy and move toward a circular economy by using a closed-loop approach where organics collection trucks can ultimately be powered by the waste product they collect. It also supports the goals of TransformTO, the City’s Climate Action Strategy.
The first green molecule of RNG is expected to flow by late 2020.
The next facility to receive RNG infrastructure will be the Disco Road Organics Processing Facility.
The City of Toronto’s existing and closed landfill sites and anaerobic digestion (organics processing) facilities are some of the largest producers of biogas and landfill gas in Ontario. Over the last few years, the City has been looking for opportunities to harness the green energy potential of these gases and identified renewable natural gas (RNG) as a top priority for biogas management.
The City has been transitioning from diesel-powered trucks to quieter and more environmentally friendly natural-gas-powered trucks since 2010, when the first small-scale pilot hit the road. To support the move away from diesel, the City also constructed a number of natural gas fuelling stations.
After identifying RNG as a priority, the City began searching for technologies and partnerships to upgrade its biogas and landfill gas to RNG. When looking at the different technologies and options for upgrading and transporting biogas, the City took a triple bottom line approach that considered the economic, social and environmental benefits.
Through multiple studies, the City identified potential RNG production opportunities at four locations: its two anaerobic digestion (organics processing) facilities (Dufferin and Disco Road) and two of its landfill sites.
Through the four sites, it’s estimated that the City could produce approximately 64 million cubic metres of RNG per year – the equivalent in greenhouse gas emission reductions of taking 35,000 cars off the road for a year.
Both biogas and landfill gas can be upgraded to create RNG. The biogas produced through anaerobic digestion is made up primarily of methane, but also includes carbon dioxide, oxygen, nitrogen, water, sulphur, and various non-methane organic compounds.
Biogas upgrading involves purifying the gas to remove carbon dioxide and other contaminants. The result is a gas that is more than 90 per cent methane and can be injected directly into natural gas pipelines. The RNG can then be transported to the City’s natural gas fueling stations and used to fuel its trucks.
Biogas at the City’s anaerobic digestion facilities is currently flared (burned), which is common industry practice for managing biogas, but does not take advantage of its renewable energy potential.
While chemically identical to traditional natural gas, RNG is a renewable resource that can be produced using materials that are readily accessible through the City’s Green Bin organics program.
RNG is also less expensive and more environmentally friendly than fossil fuels such as diesel. Once injected into the natural gas pipeline, it can be used to fuel vehicles or provide electricity or heat to homes and businesses.
RNG generated from food waste is actually considered carbon negative, because the reduction in emissions by not extracting and burning petroleum-based fuel, and the emissions avoided by not sending organics to landfill, exceed the direct emissions associated with the production and use of RNG.