Cargo and tanker ships account for 3% of all CO2 emissions and research has shown that in one year, a single large container ship can emit pollutants equivalent to that of 50 million cars. But cargo ships are very rarely discussed when it comes to reducing emissions. This is because they are a complicated group to deal with it.
One solution is onboard nuclear reactors but this is option is way too expensive for cargo ships. Luckily, a team of researchers at Northwestern University has come up with another solution.
They have conceived of CO2-capturing solid oxide fuel cells: in other words, cells that capture “burning” traditional carbon-based fuels and store them to then be sequestered or recycled into renewable hydrocarbon fuel.
This option has only been conceived of now because it is associated with polluting carbon-based fuel, Northwestern University’s Scott A. Barnett, senior author of the study, said in a statement.
“It might be harder for people to see onboard CO2 capture as climate-friendly because it uses conventional, carbon-based fuels,” explained Barnett.
He added that people tend to turn to hydrogen fuel cells and electric vehicles when looking for climate-friendly options. But these processes are not what they seem as power from electric vehicles may come from burning coal and hydrogen is often produced by natural gas.
Barnett goes on to explain that batteries are just not an option for cargo ships as they would have to be as big as the ship to function. Projects such as the Smart Green Shipping Alliance and the Carbon War Room have also proposed that ships be propelled by renewable energy but this option has also been dismissed by Barnett and his team.
"When it comes to long-range vehicles, carbon-based fuel combined with onboard CO2 capture is arguably the best way to make these vehicles CO2 neutral," said Barnett.
To store and reuse this CO2 Barnett and his team have invented a patent-pending dual-chamber storage tank. After all the carbon emissions on board are captured by this tank they would then be offloaded as carbon to be geosequestered deep underground at each destination port. Now, that's a solution that may work.