Renewable natural gas is primarily composed of methane, typically at a concentration of 90% or greater.
Renewable natural gas (RNG), also known as biomethane, is essentially upgraded biogas. Biogas is produced from the decomposition of organic matter (like food waste, animal manure, or wastewater) in the absence of oxygen. This raw biogas typically contains methane, carbon dioxide, and trace amounts of other gases.
Key Component: Methane
The defining characteristic of renewable natural gas is its high methane content. To be classified as RNG and considered interchangeable with conventional fossil natural gas, biogas undergoes a purification process. This process removes most of the carbon dioxide and other impurities.
Based on industry standards and as noted in the provided reference:
- Renewable natural gas has a methane concentration of 90% or greater.
This high concentration ensures the fuel has similar energy content and combustion properties to fossil natural gas, making it suitable for use in existing pipelines, vehicles, and appliances.
Trace Components
While methane is the dominant component, RNG may contain trace amounts of other gases that were not completely removed during upgrading, such as:
- Carbon Dioxide (CO2)
- Nitrogen (N2)
- Oxygen (O2)
- Trace Volatile Organic Compounds (VOCs)
- Minimal levels of Hydrogen Sulfide (H2S) (typically removed to very low levels)
The goal of upgrading is to minimize these non-methane components to meet pipeline quality standards and ensure consistent fuel quality.
In essence, the composition of RNG is overwhelmingly methane, achieved through the sophisticated purification of raw biogas.
