Durham University has published an explainer addressing a persistent point of confusion in the carbon management sector: the public debate treats carbon capture as a single technology, when in practice it covers several distinct processes engineered for different emission sources and end uses.

The piece is a reminder for industry watchers that capture, transport and storage are separable value-chain segments — and that the type of capture deployed depends heavily on the concentration of CO2 in the flue gas or ambient air being treated.

Why the distinction matters

According to the Durham experts, the core reason different types of carbon capture exist is the physics and economics of separation. CO2 arrives at wildly different concentrations depending on the source: a natural gas processing stream, a cement kiln flue, a power station stack, or the atmosphere itself at roughly 0.04 percent. The lower the concentration, the more energy — and money — it takes to separate a tonne of CO2.

That is why the sector splits the field into categories such as:

• Point-source capture — scrubbing CO2 from industrial flue gases before it reaches the atmosphere, the most mature and cheapest route per tonne where CO2 concentrations are high.
• Direct air capture (DAC) — pulling dilute CO2 from ambient air, an order of magnitude more energy-intensive, but the only route that can address dispersed historical emissions.
• Carbon capture utilisation and storage (CCUS) — the downstream choice of whether captured CO2 is geologically stored or converted into products, each with different permanence profiles.

The Durham authors argue the technologies are complements rather than competitors. Point-source capture addresses today's emissions from facilities that cannot electrify quickly, such as cement and steel. DAC and nature-based removals address the emissions already in the atmosphere. Climate stabilisation scenarios that rely on reaching net zero generally require both: cutting ongoing emissions and removing legacy carbon.

Where the market stands

The explainer lands amid a build-out cycle in the UK and EU capture pipeline. clusters and storage development. What Durham's contribution clarifies is that capacity figures quoted for "carbon capture" often mix point-source capture, which scales with industrial hosts, and removals-based DAC, which scales with energy supply and storage availability — a distinction investors and policymakers routinely blur.

The experts also flag the accounting difference. Captured flue-gas tonnes prevent new emissions; DAC tonnes remove existing ones. Only the latter generates durable carbon removal credits, a market currently priced far above avoided-emission credits. Conflating the two in corporate climate pledges, the authors suggest, produces commitments that cannot be independently verified on a like-for-like basis.

What to watch

The piece functions as a taxonomy briefing rather than a project announcement: no single facility, tonnage or permitting decision rides on it. But the underlying market milestones remain the same ones that will decide whether the differentiated technologies converge or diverge — cluster sequencing decisions and storage licensing rounds, which determine how quickly point-source capture capacity gets built.