Project COLOSSUS:​ Carbon capture, offloading, onshore storage, utilisation and permanent storage

To analyse the life cycle of greenhouse gas (GHG) emissions and costs associated with onboard carbon capture and storage (OCCS) across the entire carbon value chain. Life cycle assessment (LCA) is based on an OCCS system installed on a medium range tanker.

• Analyse the total value chain CO₂ emissions associated with adopting OCCS

• Estimate the carbon abatement cost considering different utilisation pathways

• End-to-end value chain perspective: LCA of OCCS solutions must account for GHG emissions across the carbon value chain, i.e., from upstream production of marine fuels to downstream final disposition of CO₂ that is emitted from fuels combustion and captured onboard.

• MEA-based OCCS more mature: Conventional monoethanolamine (MEA)-based OCCS is most mature, and its deployment on a heavy fuel oil (HFO)-fuelled ship can result in a well-to-wake (WtW) GHG emissions savings of 28.5% when the gross capture rate is 40%.

• Using biofuels with OCCS: When biofuels (biodiesel, bio-LNG and bio-methanol) is used instead of HFO, the WtW GHG emissions savings range from 69% with bio-LNG up to 121% with biodiesel from used cooking oil.

• Impact of transport and storage: Post-capture transport and permanent storage of CO₂ add minimal GHG emissions to the WtW value (~1% of the baseline emissions) when the captured CO₂ is transported for 1,000 km.

• CO₂ utilisation in concrete: Utilisation of captured CO₂ to produce concrete can increase the GHG emissions savings from a base case of 28.5% to 60% across the carbon value chain because its use partially displaces the need for carbon-intensive cement.

• CO₂ utilisation in e-methanol production: Captured CO₂ can be used to produce e-methanol with renewable electricity. With the base case of the OCCS vessel reducing its GHG emissions by 28.5%, the vessel consuming the e-methanol produced from this captured carbon can claim a GHG emissions savings of 17% (due to use of renewable electricity).

• Cost of avoided carbon: The cost of avoided carbon for OCCS with permanent storage is USD 269-405/tCO₂ for a 40% gross capture rate onboard an mediaum range tanker, considering a full-scale, Nth-of-a-kind OCCS system with full heat recovery.