What is biomethanization?

In recent years, with the completion of major projects such as the SEMECS biomethanization center in Varennes and the CBMO (Centre de Biométhanisation de la Matière Organique) in Quebec City, there has been more and more talk in the media about biomethanization, and even anaerobic digestion.

But do you know what it’s all about?

Biomethanization is the transformation of organic matter (table scraps, sludge from municipal water treatment plants, residuals from the agri-food industry, etc.) by anaerobic bacteria into a biogas composed mainly of methane and carbon dioxide. This process also generates a solid fraction known as digestate. Digestate, which contains fertilizing elements such as phosphorus and nitrogen, can be used as a soil amendment and/or natural fertilizer once it is composted. The bacteria involved in these reactions are anaerobic, as they live in an oxygen-free environment. The transformation of organic matter must therefore take place in a hermetically sealed reactor known as a “digester” or a “methanizer”.

Biomethanization, also called anaerobic digestion, is a succession of four complex biological reactions carried out by different types of anaerobic bacteria.

Source : https://aile.asso.fr/biogaz/ressources-outils/la-biologie/

The different bacteria involved in these reactions each have their own optimal functioning mode, and many parameters influence anaerobic digestion, such as pH, alkalinity, temperature, volatile fatty acid concentration, nitrogen compound concentration, and the percentage of dry matter, etc.

Unlike Europe, where the technology is widespread, the process of biomethanizing organic matter to produce biogas is still in its infancy in Quebec, with the commissioning of the Saint-Hyacinthe biomethanization plant in 2018.

Nevertheless, with Énergir’s goal of achieving a 10% injection rate of RNG (Renewable Natural Gas) into its network by 2030, there is currently a great deal of interest in new biomethanization projects in Quebec. As a result, the required expertise is currently developing with regards to the design, construction, and operation of biomethanization plants.

At AQUASAN, we understand and know the challenges of this new industry, and we are here to assist you, whether it’s regarding the choice of polymer for the digestate dewatering stage, foam management, or the micronutrients needed to boost the biomass responsible for anaerobic digestion.