Biogenic CO

2

Placing biogenic carbon dioxide from anaerobic digestion into industrial markets and permanent carbon removal.

The Resource

Anaerobic digestion produces raw biogas, composed of biomethane (c.55-70%) and biogenic COâ‚‚ (c.30-45%). Unlike fossil-derived COâ‚‚, this biogenic COâ‚‚ originates from organic matter that absorbed carbon from the atmosphere during its lifetime, giving it a fundamentally different carbon lifecycle profile.

A concentrated COâ‚‚ stream is produced where biogas undergoes upgrading: a process that separates the COâ‚‚ from the methane to produce pipeline-quality biomethane for gas grid injection. Only a minority of the UK's 700-plus AD plants do this, with the majority instead burning their biogas directly in combined heat and power engines. Even among those that do upgrade, most vent the separated COâ‚‚ directly to atmosphere. It is an output with established industrial demand and significant carbon removal potential that goes, for most operators, entirely un-monetised.

The Problem Kerkap Solves

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  • For AD plants that upgrade to biomethane, the separated COâ‚‚ stream represents a significant missed opportunity. Many have limited commercial agreements to monetise it. A large part of the reason is quality: food and beverage-grade COâ‚‚ must meet the stringent purity standards set by the European Industrial Gases Association (EIGA) and the International Society of Beverage Technologists (ISBT), including strict limits on contaminants such as hydrogen sulphide, volatile hydrocarbons, and moisture. Many upgrading plants, particularly those processing mixed waste feedstocks, produce CO2 that falls outside these specifications, closing off the highest-profile routes to market.

    The result is that operators default to venting. But the industrial market for CO2 extends well beyond food and beverage. Kerkap focuses on unlocking value from streams that the food-grade market cannot absorb, from industrial use cases to permanent geological storage.

  • Biogenic COâ‚‚ from AD plants is not just an industrial commodity; it can also be permanently removed from the atmosphere through carbon dioxide removal technologies.

    For companies with residual emissions that cannot be eliminated through operational changes alone, high-integrity carbon removals are an increasingly urgent long-term requirement. Recognised frameworks, including the Oxford Offsetting Principles and emerging SBTi guidance on removals, clearly recommend the need for genuine carbon removals, directing corporate buyers toward durable, independently verified, technology-based solutions with high permanence of carbon sequestration.

    Bioenergy with Carbon Capture and Storage (BECCS) represents an established pathway to meet these criteria. Biogenic COâ‚‚ is captured during the upgrading stage at the AD plants and transported to geological storage sites for permanent sequestration. Because the carbon originated from organic matter that absorbed it from the atmosphere during its lifetime, capturing and storing it constitutes a verified net removal. COâ‚‚ from genuine waste-fed AD plants has the strongest carbon lifecycle from a sustainability perspective, as little to no emissions from the original biomass growth need to be associated with the waste. The UK Government has identified BECCS as a critical technology in its carbon removal strategy, with the Climate Change Committee's Seventh Carbon Budget projecting that BECCS will account for most of the UK's engineered removals through the 2030s and 2040s. Corporate demand for credits of this quality currently outpaces supply significantly.

How we work

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How We Work

  • Kerkap sources biogenic CO2 from AD operators and places it with industrial buyers. Our model mirrors the mandate-based model we use for RGGOs. We assess each plant's CO2 quality and feedstock profile and match them to the appropriate end market. A key focus for Kerkap is unlocking value from CO2 streams that do not meet food-grade certification requirements, with applications ranging from wastewater treatment to industrial fabrication. Once we have identified the right buyer, we structure the offtake agreement and manage the commercial relationship on behalf of the AD operator.

  • Kerkap is developing BECCS carbon removal projects in the United Kingdom, targeting long-term CO2 offtake agreements with AD operators and connecting their output to geological storage infrastructure. Carbon removal credits generated through these projects are sold to corporate buyers under multi-year offtake agreements. This provides AD operators with a new, long-term contracted revenue stream from CO2 and provides buyers with high-integrity, independently verified technology-based carbon removals.