Renewable natural gas, or biomethane, is biogas upgraded to pipeline standards. In landfills, at agricultural sites, and in wastewater treatment plants, if there is no oxygen, bacteria decompose organic matter to produce biogas. This process is called anaerobic digestion. Raw biogas has less methane and more impurities than fossil natural gas. The impurities must be removed to produce pipeline-quality biomethane.
Different sources of biogas mean different compositions that must be considered when biogas is upgraded. The cost of biomethane depends on the required processing to purify it. Raw biogas can be used in certain applications such as boilers, but it is not suitable for vehicle use.
Renewable natural gas can be used interchangeably with fossil natural gas. It represents an emerging opportunity to use local waste resources to produce a near-zero emission fuel. The Canadian gas distribution industry recently developed a guideline defining the requirements for renewable natural gas to be considered for injection into the local natural-gas network.
Some Canadian utilities such as FortisBC are already delivering renewable natural gas to their customers and other utilities have applied for approval to deliver renewable natural gas in their distribution systems.
GazMétro recently announced the construction, in Rivière-du-Loup, QC, of Canada’s first liquefied biomethane station for trucks. The station will be supplied with fuel produced by upgrading biogas from local wastes sources. A twenty-year fuel supply agreement is now in place to support this project.
Several municipalities and private companies in Canada are also considering renewable natural gas as a vehicle fuel. For example, the City of Surrey, British Columbia, plans to use biomethane produced from municipal wastes as fuel for refuse-collection trucks starting in 2014. In the province of Québec, EBI, a private refuse-collection company, will be using biomethane, as soon as 2013, for 45 of its vehicles running on renewable compressed natural gas.