Advances in low-pressure CO2 carriers

A full-scale testbed at HD Korea Shipbuilding & Offshore Engineering (HD KSOE) underpins the company’s push into low-pressure (LP) liquefied CO2 carriers, with trials that demonstrated cargo handling, reliquefaction and emergency operations on representative equipment and procedures.

The engineering centred on operating at LP conditions that allowed bi-lobe Type C tanks and higher volumetric efficiency.

Structural integrity was addressed using an engineering critical assessment (ECA) methodology aligned to the International Gas Carrier (IGC) Code and BS 7910 fracture-mechanics practice.

HD KSOE outlined the operating envelopes it developed: LP storage at about 5.5–8 barg and medium-pressure (MP) storage at about 12–19 barg. The programme included a demonstrated transfer from MP to LP conditions. Test campaigns covered normal and emergency scenarios to evidence stability and control across the range.

Procedurally, the team reported at Gastech 2025 in Milan, it had executed drying, gasing-up, pressurising above the CO2 triple point at 4.1 barg to avoid dry-ice formation, and cool-down until tank temperature fell below −45°C ahead of loading. Data from the facility indicated tank pressure remained within the intended band while temperature declined during cool-down.

Assurance milestones included approval in principle for cargo-handling systems on a 22,000-m³ LP CO2 carrier and a 12,000-m³ MP CO2 carrier, material and integrity verification for 20,000-m³ MP and 22,000-m³ LP tank designs, and application of the ECA framework to critical features such as bi-lobe Y-joints.

Commercially, HD Hyundai reported the world’s first order for a 22,000-m³ LP CO2 carrier, which is under construction.

The company positioned these results as enabling larger-class LP carriers and the scale-up of carbon capture and storage (CCS) value-chain logistics.