Seabound

Seabound is a London-based climate technology company that designs and installs onboard carbon capture equipment for cargo ships. The system is mounted adjacent to a vessel's funnel and routes flue gas through a reactor where CO₂ binds with a sorbent to form solid limestone/carbonate pebbles, capturing a target rate of between 25% and 95% of the CO₂ in the exhaust. The equipment is described as retrofittable to existing vessels, compact, fully automated and remotely monitored. The company states its system also captures sulphur alongside CO₂ from engine exhaust.

When a ship docks, the carbonate pebbles are collected and offloaded at key ports and post-processed on shore, yielding regenerated pebbles for reuse and pure CO₂ that can be sequestered or sold for utilisation, including electro-fuel production and cement feedstock. Seabound positions this as an option available today for shipowners facing International Maritime Organization rules requiring emissions cuts of 40% by 2030, on the argument that hydrogen and ammonia fuels remain 10–20 years from maturity and that efficiency measures and slow steaming are insufficient.

The company was founded in 2021, took part in Y Combinator's Winter 2022 batch, and had a team size of 18 as of the Y Combinator listing. Employee ranges reported elsewhere span 6–20 and 11–20.

Founding story

Seabound was founded in late 2021 by Alisha Fredriksson (Co-Founder and CEO) and Roujia Wen (Co-Founder; listed as CTO by Lowercarbon Capital and as Co-Founder & Advisor on the company site). Before Seabound, Fredriksson helped build the maritime electro-fuel startup Liquid Wind, launched a climate program and managed global partnerships at the non-profit Generation, was part of the founding class at Minerva University, and started a social enterprise called Seema as well as the climate activist group Green New Deal London. Wen previously built machine learning products for Amazon Alexa and holds a master's degree in theoretical physics from the University of Cambridge.

Business model

Seabound designs, installs and operates carbon capture equipment aboard customers' ships, emphasising low capital expenditure for shipowners. Alongside equipment sales it handles collection and offloading of the captured carbonate at ports, recycling of the sorbent, and downstream disposition of the CO₂ — either sequestration or sale for utilisation such as fuel production or cement inputs. Website enquiry categories indicate distinct commercial lines for carbon capture equipment customers, CO₂ feedstock customers and carbon credit customers.

Revenue lines indicated by the company's own materials include sale or installation of carbon capture equipment, sale of captured CO₂ as feedstock (for example for electro-fuels or cement production), and carbon credits. Lowercarbon Capital states that the pure CO₂ streams produced from post-processing can be sold to help cover installation costs. Public grant funding, including UK government Clean Maritime Demonstration Competition awards and a European Space Agency award, has also supported the business.

Traction

Reported milestones include a first prototype capturing CO₂ at 95% efficiency, six letters of intent from major shipowners, an onboard pilot with Lomar Shipping and Hapag-Lloyd achieving about 80% capture efficiency on a container ship in the Middle East, a port-based demonstration at the Port of Long Beach with STAX Engineering and Wallenius Wilhelmsen at about 95% efficiency, £2.2 million in UK government grants via the Clean Maritime Demonstration Competition, a £1.1 million UK government grant for the Port of Southampton project, a €1.5 million European Space Agency award, and completion of its first full-scale maritime carbon capture units in February 2026. Cumulative funding of $6.8 million is reported by Climatebase.

Latest developments

In February 2026 Seabound held an event in Doncaster marking completion of its first full-scale maritime carbon capture units and a €1.5 million European Space Agency award. In August 2025 it won a £1.1 million UK government grant to deploy carbon and emissions capture at the Port of Southampton. During mid-2025 it announced a carbon capture partnership involving a cement plant, with a cement transport ship producing cement ingredients while sailing. A June 2026 trade report describes the company, built for the shipping industry, as also looking at AI data centres. The company was recruiting a Head of Business Development in London.