The first commercial-scale trial of an innovative technology for onboard capture of carbon dioxide emissions from shipping vessels has been slated for later this year.

Seabound, a U.K. startup, will install a unit around the size of a shipping container on the deck of the UBC Cork, a 5,700-metric-ton vessel that carries cement from Heidelberg Materials, one of the world’s largest producers of the building material. The vessel’s exhaust will be routed over CO₂-absorbing material in the container, safely locking away a portion of the vessel’s emissions.

The trial comes at a time of mounting pressure on the maritime shipping industry, which generates around a billion tons of CO₂ annually, or roughly 3 percent of the global total. The International Maritime Organization, the United Nations agency that regulates the sector, recently announced plans for emissions-intensity rules that would force large vessels to cut emissions by up to 43 percent by 2035.

Additional advantage

Onboard carbon capture appeals because existing vessels can be retrofitted relatively quickly and cheaply, said Lars Erik Marcussen, logistics project manager at Heidelberg Materials Northern Europe. In the coming tests, the system will capture 25 percent of the CO₂ emitted by the vessel, but the technology can achieve up to 95 percent capture, according to Seabound.

Onboard capture has an additional advantage for Heidelberg: the process involves reacting pebbles of calcium hydroxide, commonly known as lime, with CO₂ to produce calcium carbonate, or limestone, which is an input into cement production.

“We can take the limestone pebbles and put them straight into our cement kilns,” said Marcussen.

The UBC Cork is one of nine vessels that Marcussen oversees. If the trial is successful, he hopes to install the carbon capture technology on an additional vessel every year. The work complements capture technology that Heidelberg has installed at its cement plant in Brevik, Norway, which now captures 400,000 tons of CO₂ annually.

Energy expenses

One challenge to be surmounted before the technology scales is the production of low-carbon lime. The issue is serious enough to give some experts doubts about Seabound’s approach.

“There are systems that regener