Onboard Carbon Capture and Storage (OCCS)
OCCS is an emissions-abatement technology, not a fuel or energy source; CII/EEXI/NZF accounting, testing, survey and certification remain to be established by applicable instruments.
Operational Explanation
OCCS captures CO₂ on board and retains it for subsequent transfer; it is not a fuel. The balance must include additional heat and electricity consumption and the carbon destination. A high capture rate does not automatically equal the same net emissions reduction. Installation and integration require ship-specific assessment.
The IMO work plan revised at MEPC 84 aims to complete the framework in 2028: this is a work target, not an entry-into-force date. IMO rule development, installation approval and performance verification are distinct. DNV-RP-0698, announced on 22 June 2026, already provides a mass-balance measurement framework; it does not itself confer CII/EEXI credits.
Regulatory Reference
MEPC 84/16/Add.2, Annex 19 — revised OCCS work plan; IMO — London Protocol, CCS; DNV-RP-0698 — technical framework announcement; DNV — integration and energy. DNV references are technical and do not replace applicable law.
The public DNV announcement of RP-0698 describes capture metrics, CO₂ quantities, atmospheric emissions and third-party verification covering measurements, calculations and uncertainty. Agreeing a performance test requires the applicable text and project acceptance criteria; the announcement alone does not provide a complete conformity procedure.
Scope of Application
Assess capture, temporary onboard storage, delivery, transport and final destination separately. The London Protocol concerns, as relevant here, storage in sub-seabed geological formations and associated export; it is not general permission to discharge CO₂ into the sea. For cross-border transfers, verify relevant provisional-application declarations, agreements, permits and national law.
Procedure / How to Complete It
- Agree design and approvals with flag and class, assessing stability, space, access and operational safety.
- Define balance boundaries, captured CO₂, additional consumption and measurement uncertainty.
- Trace delivery and destination; identify the authorized recipient and interface compatibility.
- Apply only the methodology recognized by the relevant regime; do not unilaterally deduct captured CO₂ from CII.
Practical Example
Captured CO2 is measured and managed under the approved project but does not automatically create CII credit.
What Typically Goes Wrong
Calling OCCS a lower-intensity energy source or promising settled future accounting.
Common Mistakes Mistake Library
| Mistake | Consequence | How to Avoid It |
|---|---|---|
| Calling OCCS a lower-intensity energy source or promising settled future accounting. | Non-compliant decision or treatment | Follow the approved arrangement and applicable sources |
What the PSCO Checks
Operational Tips
- Reconcile captured quantities, onboard inventory and delivered quantities with verifiable documents.
- Distinguish permanent storage from carbon utilization: do not assign the same climate outcome without checking its fate.
- Keep approvals, performance evidence and the regulatory accounting basis distinct.
Preparation checklist
- Abatement not fuel
- Approval
- Current accounting
- London Protocol
- No assumed credit
FAQ
Related Topics
Last substantive revision of this page: 16 September 2026 · page fingerprint 4a3bc96e2576