Project REMARCCABLE:​ Realising maritime carbon capture to demonstrate the ability to lower emissions​

To understand the challenges associated with the retrofit of an onboard carbon capture and storage (OCCS) system on a medium range (MR) tanker

• Conduct front-end engineering design study of a carbon capture system

• Develop cost estimate for a retrofit OCCS system

• Assess economic trade-offs and abatement cost

• CAPEX: At a capital expenditure (CAPEX) of USD 13.6M (+/-15%) for the capture system, liquefaction system and onboard storage tank, the retrofit OCCS system that was designed for Stena Impero can achieve 19.7% annualised net CO₂ avoided at a 9.2% fuel penalty.

• OPEX: The OPEX for the OCCS retrofit was estimated at USD 830K per year for additional support personnel, additional fuel consumption, maintenance and periodic amine replacement.

• Abatement cost: The total abatement cost for this retrofit system, with CAPEX amortised over the remaining life of the vessel, is USD 769/tCO₂. Abatement cost can come down by approximately 75% through increased system size, economy of scale, amongst others factors.

• Modular integration: The carbon capture system was designed into a mega skid module for easy onboard integration.

• Thermal energy requirement: Available waste heat energy is the critical factor in determining the fuel penalty. With its existing boiler system, the Stena Impero needs a mechanical reconfiguration to increase available thermal energy for operating the OCCS system.

• HAZID, HAZOP and AIPs: Hazard identification (HAZID) and hazard and operability (HAZOP) reviews of the retrofit carbon capture system resulted in Approvals in Principle granted by ABS and Lloyd’s Register.

• Carbon intensity indicator (CII) compliance: The Stena Impero can maintain its CII rating of “C and better” for an additional 9 years with this retrofit, allowing it to operate in compliance until the end of its vessel life, assuming a CII reduction factor of 2% from 2027 onwards.

• Key barriers: While the engineering analysis revealed no major technical barriers to adapting a carbon capture system for use on marine vessels, the primary barriers remain commercial in nature including an initially high abatement cost and a lack of infrastructure for offloading captured CO₂ at ports and terminals.