There are vast reserves of renewable energy accessible in Québec in the form of biogas produced by organic matter. By exploiting this resource, municipalities and other organizations can turn a profit on their wastes while reducing their environmental footprint.
This winter, Saint-Hyacinthe became the first city in Québec to produce its own natural gas from organic matter. The selective collection of ‘brown bags’ from citizens is thus helping heat the City’s buildings and fuel its vehicles at low cost, while reducing greenhouse gas (GHG) emissions. The surplus renewable natural gas will then be sold to Énergir.
Saint-Hyacinthe’s idea is likely to gain ground in Québec, for both its economic and its environmental advantages. In fact, landfilling organic wastes generates about 6% of the province’s GHG emissions due to a phenomenon called methanation.
When organic matter is left to decompose naturally, it undergoes a chemical reaction that releases biogas into the atmosphere. Biogas is composed of methane (50-75%), carbon dioxide (about 35%), and other impurities. The biogas can be captured and treated to produce renewable natural gas.
That is exactly what the new Centre de valorisation des matières organiques (organic recycling centre) will be doing in Saint-Hyacinthe, in partnership with Énergir. Wastes are sent there to undergo a biomethanation process, i.e., controlled methanation.
The result is biogas, which, after treatment, becomes renewable natural gas, whose energy properties are identical to those of the natural gas distributed by Énergir. The major difference is the source and the life cycle, which is infinitely renewable. And, when biogas is captured, fewer GHGs escape into the atmosphere.
A variety of energy sources
With biomethanation, there is no need to dig wells or excavate mines on the other side of the world: energy sources can be found in residues from our table and garden, from paper and carton, sludge from treatment plants, and from agricultural and agri-food industry wastes.
Once collected by the municipality, the wastes are placed in large silos where they are ‘digested’ by bacterial cultures. After 15-40 days, the organic matter disintegrates into biogas and into a compostable residue, called digestate, which can be used as an agricultural fertilizer.
The transformation of biogas into renewable natural gas includes removing impurities such as water, hydrogen sulphide (H2S) and siloxanes, then separating out the carbon dioxide to obtain a natural gas composed 97-99% of methane. In the current model being studied by the Régie de l’énergie, the producer is in charge of this part of the work. Then Énergir takes over to handle the measuring, quality control, connection of the site to its system, injection into its distribution system, and, finally, the distribution of the renewable natural gas to all its customers in Québec.
Less costly, more profitable
Besides municipalities, any organization that generates significant quantities of organic matter is a potential producer of renewable natural gas. This would help to reduce costs by meeting its own consumption needs and to make a profit by selling the surplus. The concept is even more attractive if it operates a fleet, since it can convert the vehicles to run on renewable natural gas (as is the case in Saint-Hyacinthe) and thus achieve significant savings while using a carbon-neutral fuel.
As biomethanation projects continue to be developed, we could soon expect to see a locally produced, renewable natural gas option emerge in Québec – a 100% carbon-neutral natural gas, thereby potentially turning each producer into a leader in sustainable development by directly contributing to reducing GHG emissions.