Carbon capture: compare captured CO₂ with emissions avoided
Capture is one part of a chain
IEA describes technologies that capture CO₂ for utilisation or storage. A capture rate at one exhaust stream is not the same as an emissions reduction across a factory, transport chain or product lifecycle. Ask what enters the calculation before comparing two projects. A project announcement also differs from operating evidence: an intended capture capacity does not establish how much was actually stored.
Read the project record
| Component | Evidence to request |
|---|---|
| Capture | CO₂ stream, throughput, rate, period and downtime |
| Energy | Additional fuel or electricity, and their emissions boundary |
| Transport | Route, losses, measurement and responsibility |
| Destination | Use or geological storage; monitoring and storage records |
| Comparison | Same product output and baseline; what remains excluded |
Copy units carefully. Tonnes per year of nameplate capacity, tonnes captured in a month and tonnes avoided over a lifecycle answer different questions. If only capacity is disclosed, record operating volume as unknown. Do not silently convert planned output into achieved mitigation.
A fictional boundary calculation
Suppose an unchanged production process would emit 100 tonnes in a stated period. A fictional capture system captures 90 tonnes and requires energy causing 8 additional tonnes within the chosen boundary. With no other changes, the simplified avoided amount is 90 − 8 = 82 tonnes. A 90% stream capture figure therefore differs from an 82% reduction against this baseline. This example omits upstream emissions, transport losses and storage uncertainty; it is not a lifecycle assessment or a measured plant result.
What makes a comparison useful
For an investment or policy question, compare the same service or product quantity, period and emissions boundary. Keep the source for each input and list the omitted processes. A project with a strong equipment capture rate still needs evidence for the rest of its chain. Use the worksheet to identify the next missing document rather than filling gaps with a generic cost per tonne.
Sources and scope
- IEA: carbon capture, utilisation and storage — Technology context; not a verified result for a named project.
Sources checked October 10, 2026. AI-assisted research and drafting. The examples, calculations and worksheets are Luminesca editorial work; they are not measured trials, first-hand reporting or an independent certification. Removed unsupported cost bands, project superlatives and claims of permanent storage without qualification. Report a specific correction with its source.