Renewable natural gas

Biogas and renewable natural gas, also known as RNG, are two types of bioenergy for which the production in Québec could increase sharply in the coming years.

Renewable natural gas represents a promising solution to reduce fossil fuel consumption and can contribute to reaching Québec’s GHG emission reduction targets.

Landfills

In Québec, engineered landfills are equipped with a system to capture the biogas emitted during the decomposition of organic matter.

These biogas are sometimes flared to avoid methane emissions, a potent greenhouse gas.

In some facilities, biogas is used directly to meet thermal needs, or purified to produce renewable natural gas.

Biomethanization plants can use agricultural, forestry, municipal or industrial residues to produce biogas or renewable natural gas.

These plants must be supplied with biomass on a regular basis. Depending on their purpose and local agreements, they can be supplied by:

• agricultural organic matter (hog manure);
• residues from the agri-food industry;
• industrial or forestry residues;
• municipal residues (sludge from wastewater treatment plants, municipal organic matter, etc.). 

Depending on the facility, the extracted biogas will be used locally to produce heat or purified to produce renewable natural gas.

The residues from biomethanization are called digestate. The digestate may be composted or used directly as a fertilizer.

A number of biomethanization plants are already established in Québec or are in the process of building their facilities. Their achievements can inspire future regional or municipal projects:

• Centre de traitement de la biomasse de la Montérégie 
• Coop Agri-Énergie Warwick 
• Projet de biométhanisation  in the city of Saint-Hyacinthe
• Centre de biométhanisation  in the agglomeration of Québec

Biogas can be used to: 

• produce heat – When used in a boiler, biogas provides a source of heat for cooking, heating, or industrial processes;
• produce electricity in cogeneration – Three power plants in Québec are powered by biogas and some use their residual heat.

Renewable natural gas can be used:

• for heating buildings (commercial, institutional or residential);
• for drying and cooking;
• for industrial processes in plants;
• to power the thermal engines of vehicles running on natural gas.

Renewable natural gas can easily replace fossil-based natural gas consumption. Little modification of the distribution system infrastructure is required to inject it, and natural gas-powered equipment also does not have to be adjusted.

In Québec, regulations require that the proportion of renewable natural gas distributed in the gas system must reach at least 1% starting in 2020, and then gradually increase to a minimum of 10% starting in 2030.

Starting in January 2023, all renewable sources of gas, such as renewable natural gas, as well as green hydrogen, can be included in the calculation of the proportion of renewable substances integrated into the gas system.

Renewable gases included gases produced with organic materials or renewable energies whose properties allow for direct integration into the gas system.

Biogas that needs to be cleaned up before being injected into the gas system remain excluded from the new regulations. The increased use of renewable natural gas across Québec is expected to:

• help reduce GHG emissions from all natural gas consumers;
• encourage municipal and regional renewable natural gas production projects using locally available resources.

In addition, large natural gas consumers may express an interest in being supplied with renewable natural gas from their gas distributors or directly from local producers.

The renewable natural gas production process takes place in three stages.

1. Organic matter decomposition

When organic matter decomposes in the absence of oxygen, it is called anaerobic digestion. Biomethanization plants use anaerobic digesters to optimize the process of biomass degradation, in an oxygen-free and temperature-controlled environment.

During this step, biogas, composed of methane, carbon dioxide (CO2) and other gas contaminants, is released. Biogas can be cleaned of impurities and used directly as fuel to generate heat or electricity.

2. Biogas purification

Cleaning and purifying the captured biogas enable the extraction of biomethane, a molecule identical to the methane found in natural gas.

3. Gas distribution

If it meets all quality standards, biomethane, also known as renewable natural gas or RNG, can be injected into the Québec gas distribution system, or be transferred to a local consumer. Renewable natural gas can also be liquefied or compressed.

Technology development will soon offer new ways to produce renewable natural gas. Among these, two technologies have potential for Québec: 

• Pyrogasification allows biomass to be upcycled by high-temperature treatment in the absence of oxygen. In particular, this process produces a synthesis gas that can be converted into biomethane.
• Methanation involves combining hydrogen with a source of CO2 obtained, for example, by purification of biogas, to reconstitute synthetic methane.

The production of renewable natural gas is a new energy sector with great potential but not yet fully established in Québec. Financing this type of project can be risky or still difficult, which is why the government offers a number of financial assistance programs: please refer to the French version of this page to learn more.