India’s Biogas Sector Can Be Greener, By Following This Danish Firm’s Example

Danish biogas company Bigadan opened its third carbon capture and liquefaction facility this week, at Kalundborg on the island of Zealand, taking its combined capacity above 56,000 tonnes of biogenic CO2 per year, with a stated target of 200,000 tonnes annually by 2030. The Kalundborg plant, built with Swiss technology partner Kanadevia Inova, captures CO2 released during the routine upgrading of raw biogas into pipeline-grade biomethane — a purification step every biogas producer already performs, before it purifies, compresses and liquefies it to a purity of 99.9%. Under a linked project, Kalundborg Bioenergy will permanently store 25,000 tonnes of that CO2 per year from 2026 to 2032, generating verified carbon-removal credits sold to companies seeking to offset residual emissions.

The economics are what make this worth noting rather than a routine plant opening: the CO2 in question is not a new input Bigadan is sourcing. It is the same waste stream every biogas upgrading facility in the world already separates out and, in the overwhelming majority of cases, simply vents to the atmosphere. Bigadan has turned a byproduct disposal cost into a second product line, on top of the biomethane it was already selling.

India makes the identical byproduct, at serious scale, and wastes it

India’s growing compressed biogas (CBG) programme, run under the SATAT scheme, is built on precisely the same chemistry. Raw biogas is roughly 55-65% methane and 35-45% CO2; upgrading it to CBG for use as vehicle fuel or grid injection strips out that CO2 as a matter of routine, in every one of the more than 70 CBG plants already commissioned nationally, with several hundred more in the pipeline. The Council on Energy, Environment and Water (CEEW) has flagged this directly: CO2 produced during CBG purification and upgrading “is currently wasted,” at a rate of roughly half a tonne of CO2 for every tonne of CBG produced — a byproduct stream that scales in direct proportion to a programme the government is actively trying to grow.

India’s CBG plants do already earn carbon-credit revenue, but through a different, narrower mechanism: methane-avoidance credits under voluntary schemes, priced for avoiding the release of biogas methane that would otherwise escape untreated, with export buyers reportedly paying $8-12 per tonne of CO2-equivalent avoided. That’s a real and useful revenue stream, but it’s structurally distinct from what Bigadan is doing. Capturing and permanently storing the CO2 that upgrading itself produces, which generates carbon-removal credits rather than avoidance credits, and which India’s CBG economics don’t currently touch at all.
CO2 produced as a byproduct during purification and upgrading of CBG is currently wasted,  disposal of this byproduct remains one of the sector’s persistent challenges.

What would need to change

The gap is a capital and infrastructure one, not a technical mystery.  CBG plants already run CO2-removal purification systems (PSA, membrane separation, amine scrubbers) as a normal part of the upgrading process; the missing piece is the liquefaction and permanent-storage layer Bigadan has now built three times over. India lacks both the CDR-project infrastructure to store captured CO2 permanently at scale and, so far, the policy signal that would make individual CBG developers prioritise adding it. With SATAT-linked plants already numbering in the hundreds and the government’s own blending obligations set to rise through the decade, the byproduct volume is already there. What’s missing is a financing and registry pathway that turns India’s compressed biogas boom into a carbon-removal one as well — the same upgrade Denmark’s biogas sector has now made three times, on a fraction of India’s feedstock base.