Seabound develops compact, modular carbon-capture units sized to standard 20-foot containers that can be integrated onto barges or fitted to ships without vessel retrofits. Its core offering is designed to connect to ship exhaust and, when combined with STAX Engineering’s barge-based emissions capture system, enables at-berth removal of particulate matter, NOx and SO₂ before CO₂ is isolated and stored. The combined solution has been proven in demonstrations at the Port of Long Beach and in shipboard pilots, with Seabound reporting roughly 78–80% CO₂ capture efficiency and over 90% SO₂ removal; STAX reports up to 99% PM and 95% NOx removal prior to capture. Seabound plans to refine next-generation systems, test container-swapping logistics, and establish a fleet of barges to cover key berths as a scalable alternative to shore power. Founded in late 2021, the company has raised $6.8M from investors (including Lowercarbon Capital, Y Combinator, Eastern Pacific Shipping, Elemental Impact, and Collaborative Fund) and received £2.3M in UK CMDC grant funding to date. Seabound aims to capture 100 million tonnes of CO₂ annually by 2040 and is engaging shipowners, cargo companies, ports and industrial partners to expand adoption and commercialization. Seabound is prototyping a lime‑based carbon capture system that routes ship exhaust into containers filled with porous calcium oxide pebbles which bind CO2 to form calcium carbonate. The system is designed so most CO2 processing happens on land; returned limestone can be sold as‑is or heated to release carbon for sale or sequestration and to regenerate calcium oxide for reuse. The company says its approach can reduce emissions by as much as 95% and requires less onboard space and energy than solvent‑based methods. Seabound has signed six letters of intent with major shipowners and aims to trial the technology aboard ships beginning next year. The startup is Y Combinator‑backed and led by co‑founder and CEO Alisha Fredriksson, with CTO Roujia Wen; Fredriksson previously helped build maritime fuel startup Liquid Wind and Wen worked on AI products at Amazon. To date Seabound has raised a $4.4 million seed round to advance prototyping and trials.

Total raised

$6M

Funding rounds

2

Latest round

Grant

Latest activity

Aug 2025