The maritime shipping industry is about to embark on a significant trial that could reshape its approach to carbon emissions. Later this year, the U.K. startup Seabound will install a commercial-scale carbon capture unit on the deck of the UBC Cork, a 5,700-metric-ton vessel that ferries cement for Heidelberg Materials. This trial comes as the industry faces mounting pressure to cut emissions, with the International Maritime Organization (IMO) recently announcing plans to force large vessels to reduce emissions by up to 43 percent by 2035.
The technology, roughly the size of a shipping container, will capture a portion of the vessel’s CO2 emissions by routing the exhaust over CO2-absorbing material. While the initial trial aims to capture 25 percent of the vessel’s emissions, Seabound claims the technology can achieve up to 95 percent capture. This is a significant step, given that maritime shipping generates around a billion tons of CO2 annually, accounting for roughly 3 percent of the global total.
One of the appeals of onboard carbon capture is its potential for quick and relatively cheap retrofitting of existing vessels. Lars Erik Marcussen, logistics project manager at Heidelberg Materials Northern Europe, highlighted this advantage. The trial also offers an additional benefit for Heidelberg: the process involves reacting pebbles of calcium hydroxide (lime) with CO2 to produce calcium carbonate (limestone), which is an input into cement production. “We can take the limestone pebbles and put them straight into our cement kilns,” Marcussen said. If successful, he hopes to install the carbon capture technology on an additional vessel every year.
However, challenges remain. The production of low-carbon lime is a significant hurdle. Felix Klann, maritime transport policy officer at Transport & Environment, expressed doubts about Seabound’s approach due to the energy-intensive process of regenerating limestone. “There are systems that regenerate limestone back into calcium oxide, but this is a very energy-intensive process that incurs significant costs, even with 100 percent green electricity,” Klann said. He suggested that shipping companies should focus on avoiding emissions altogether by investing in green e-fuels, electrification, and designing efficient ships.
Alisha Fredriksson, Seabound’s co-founder and CEO, acknowledged the cost challenges but expects them to decrease as the technology scales. She anticipates costs to come down to around $150 per metric ton of CO2 capture. She also noted that once the cost of complying with IMO rules and the European Union’s Emissions Trading Scheme are factored in, the process will produce savings that pay back upfront costs within one to five years.
Seabound is also working to identify sources of low-carbon lime. Currently, the emissions associated with producing and transporting the lime outweigh the benefits of capturing CO2 from the ship’s exhaust. “We’re working with lime companies to ensure that there is a supply of green lime for our full-scale deployments,” Fredriksson said. “We want to team up with lime companies to develop dedicated kilns as close to the port as possible, so we can reuse the material over and over and then either sequester or sell that pure CO2.”
This trial could spark a wave of innovation in the maritime industry. If successful, it could pave the way for widespread adoption of onboard carbon capture technology, significantly reducing the industry’s carbon footprint. However, it also highlights the need for a holistic approach to decarbonization, balancing the potential of carbon capture with investments in green fuels and efficient ship design. The coming months will be crucial in determining the viability and scalability of this technology, setting the stage for a greener future in maritime shipping.