bioCNG

bioCNG is a form of renewable natural gas produced from biogas that has been upgraded to pipeline-quality methane and compressed to CNG pressure for use as a transportation fuel or for injection into the natural gas grid. The term highlights the compressed, vehicle-ready form of biomethane, differentiating it from the broader gas stream that may be injected into pipelines.

Production and upgrading: Biogas is generated primarily through anaerobic digestion of organic feedstocks such as manure, food waste, wastewater biosolids, and agricultural residues. To become bioCNG, the biogas is cleaned and upgraded to a high methane content by removing carbon dioxide and impurities (such as hydrogen sulfide, water, and siloxanes). Upgrading technologies include water or solvent-based scrubbing, amine or chemical scrubbing, pressure swing adsorption, membrane separation, and cryogenic methods. The resulting gas typically contains more than 95% methane.

Applications: bioCNG is used as a renewable vehicle fuel in compressed natural gas (CNG) engines and can also be injected into existing natural gas pipelines as RNG (renewable natural gas). It is compatible with current CNG infrastructure and fueling stations and is suitable for fleets such as buses, trucks, and municipal vehicles.

Environmental and policy relevance: Using bioCNG reduces greenhouse gas emissions by capturing methane that would otherwise be released and by displacing fossil natural gas. It participates in programs and incentives in markets worldwide, such as carbon-intensity standards and renewable fuel schemes, which support development and adoption of RNG and bioCNG.

Notes: bioCNG is essentially RNG compressed for vehicle use; RNG and bioCNG are often used interchangeably, though bioCNG specifically denotes the compressed form for CNG applications.