CBG, biogas, biomethane and RNG — the same molecule, different markets

Biogas is the raw gas from anaerobic digestion. It is typically a mixture of methane and carbon dioxide with hydrogen sulphide, moisture and traces. It is not yet a transport-fuel specification.

Biomethane is biogas that has been cleaned and upgraded so methane is high enough, and impurities low enough, to meet a fuel or grid code. In India that upgraded, compressed product is called Compressed Bio Gas, or CBG, and often marketed as Bio-CNG. In Europe the usual word is biomethane. In North America it is Renewable Natural Gas, or RNG.

Sponsors lose time when they treat these as different technologies. The digestion and upgrading physics are related. The offtake model is not: Indian SATAT cascades at 250 bar are a different commercial object from European grid injection or US pipeline interconnection.

Saimona uses CBG as the primary term on this website, with biomethane, Bio-CNG and RNG as supporting vocabulary so international buyers can find the same conversation.

If a brief mixes those words as if they were different plants, the first job is to name the offtake. The molecule is upgraded methane. The project is whoever will take it, at what pressure, and under which code.