Compressed Biogas
The fuel made from exactly what you would otherwise throw away
Picture a sealed tank where organic waste, cow dung, crop residue, kitchen scraps, is left to decompose without oxygen, naturally releasing a gas rich in methane as it breaks down. Purify and compress that gas enough, and it becomes a fuel that behaves almost identically to CNG.
Compressed Biogas is produced by anaerobic digestion of organic waste, followed by purification to strip out impurities and carbon dioxide, and finally compression to the same standard used for CNG, making it directly usable in CNG vehicles or blendable into the existing gas pipeline network. Beyond the fuel itself, the leftover residue from the digestion process, called digestate, is a genuinely useful organic fertiliser, giving CBG plants a valuable secondary revenue stream alongside the gas.
CBG is promoted primarily through the SATAT scheme, and it represents one of the more elegant pieces of India's energy transition story, converting a waste disposal cost into both a transport fuel and a fertiliser, from feedstock that would otherwise have simply been discarded or burnt.