Calcarea, a startup founded by Caltech chemical oceanographer Jess Adkins, has invented a new technique for reducing carbon emissions from international shipping by capturing and storing CO2 in the ocean.
The method, which mimics natural processes, might help the maritime sector meet its climate targets by converting CO2 emissions into stable ocean salts that can be stored for up to 100,000 years.
International shipping is responsible for about 80% of global trade and contributes around 3% of total carbon emissions.
The International Maritime Organization (IMO) has set stricter emission standards, aiming for net-zero emissions by 2050. However, the adoption of low-emission fuels such as methanol, hydrogen, and ammonia is not advancing fast enough.
Calcarea’s innovation offers a potential solution by equipping cargo ships with reactors that convert CO2 from exhaust emissions into bicarbonate salts through a reaction with seawater and limestone.
The technique accelerates a natural reaction in which saltwater absorbs CO2 and creates bicarbonate salts. This reaction normally takes over 10,000 years but is sped up to around one minute in Calcarea’s reactors.
The concept involves funnelling exhaust fumes into a reactor on the ship’s hull, where they are mixed with seawater and limestone to produce salty water that traps CO2. The resulting water is discharged into the ocean, where it poses no danger to marine life.
Calcarea has already developed two prototype reactors, one at the Port of Los Angeles and another at USC. The startup has formed a partnership with Lomar, an international shipping company, to test a full-scale prototype.
The reactors will be customized for a variety of ship sizes, including the massive Newcastlemax class.
Despite the promising technology, several technical issues remain, including integrating reactors onto ships and managing limestone supply chains. The cost of CO2 capture with this method is now estimated to be $100 per ton.
Calcarea’s approach has various advantages over traditional carbon capture technologies.
Unlike scrubbers, which catch sulfur emissions but not CO2, Calcarea’s reactors capture sulfur during the CO2 removal process. Furthermore, Calcarea’s approach speeds up a natural process without increasing ocean acidity, preventing harm to marine life.
The startup envisions its technology not only assisting the maritime industry to adapt to cleaner fuels but also potentially evolving to manage CO2 gathered on land.
Adkins predicts a future in which purpose-built ships can efficiently store CO2 from the atmosphere, offering a viable alternative to underground storage options.
Reference: CNN
