Seabound vs Zeffy

About

Seabound is a maritime carbon capture technology company developing systems that capture CO2 from ship exhaust directly onboard vessels, storing it as calcium carbonate for offloading at port — enabling the shipping industry to reduce emissions without switching to alternative fuels. Founded in 2021 and headquartered in London, Seabound has raised approximately $4.8 million in seed funding and is developing a post-combustion carbon capture approach that can retrofit onto existing ships without requiring engine replacements or fuel changes.\n\nSeabound's system works by diverting flue gas from a ship's engine exhaust through a reaction chamber containing calcium oxide (quicklime), which reacts with CO2 to form calcium carbonate — a solid, stable material that can be offloaded at port and sold as a feedstock for construction materials or industrial processes. This chemistry eliminates the need for compressed CO2 storage or cryogenic liquefaction, which are significant technical and safety challenges for onboard carbon capture. The calcium oxide can be regenerated at port facilities.\n\nIn 2025, Seabound operates in the emerging maritime decarbonization market where the International Maritime Organization (IMO) has established targets to cut shipping emissions 50% by 2050. Maritime shipping is responsible for approximately 2.5% of global CO2 emissions, and the sector faces growing regulatory pressure (EU ETS carbon pricing extending to shipping from 2024). Seabound competes with other maritime carbon capture startups and against alternative decarbonization approaches (ammonia fuel, hydrogen, LNG). The 2025 strategy focuses on completing pilot installations on commercial vessels, demonstrating the techno-economic case for operators, and partnering with port infrastructure providers for calcium oxide supply and calcium carbonate offtake.