Advancements and challenges of onboard carbon capture and storage technologies for the maritime industry: a comprehensive review

In response to the growing demand of reducing greenhouse gas (GHG) emissions within maritime sector, Onboard Carbon Capture and Storage (OCCS) technologies provide as key solutions for tackling carbon dioxide (CO2) emissions from ships. This review paper offers a comprehensive overview of recent developments, challenges, and prospects of Carbon Capture and Storage (CCS) technologies considering specifically for onboard ship applications. Various Carbon Capture (CC) methods, ranging from post-combustion and pre-combustion capture to oxy-fuel combustion, are critically analysed concerning their operating principles, advantages, disadvantages and applicability in the maritime context. Temporary onboard CO2 storage is examined in its gaseous, supercritical, solid, and liquid states. In this regard, solid and liquid forms are found promising, although solid storage is not yet commercially mature. The review also addresses the challenges in implementing the CC technologies on ships, including space constraints, energy requirements, safety concerns, and economic viability. A comparative assessment is conducted to determine the most promising OCCS technologies. The study finds that post-combustion CC by chemical absorption requires more space than cryogenic and membrane separation, with the latter two deemed viable options, albeit with trade-offs in energy consumption and cost. The study would provide valuable insights and ideas for further research in the field of OCCS technologies.