A container ship has hit the seas fitted with an onboard carbon capture system that allows it to trap some of its carbon emissions while it makes its voyage.

The experimental pilot project was recently carried out by Seabound, a London-based climate tech startup that’s come up with an inventive way to decarbonize shipping. 

Their carbon capture technology was fitted on the Sounion Trader container ship during a two-month voyage from Turkey to the Persian Gulf. According to the company, the device captured 78 percent of carbon emissions and 90 percent of sulfur dioxide from one of the ship’s auxiliary engines.

“While still early days, our first pilot project proves that our technology works and that it is possible to take on this huge, complex problem,” Alisha Fredriksson, CEO and co-founder of Seabound, told The Next Web.

“This breakthrough demonstrates that the shipping industry doesn’t have to wait for new fuels or solutions to reduce its emissions in the future – we can start to capture carbon from the existing fleet right now,” explained Fredriksson. 

Off the back of this success, Seabound now aims to build a “bigger and better” system capable of removing up to 95 percent of the carbon dioxide, which they say could arrive on the market by next year.

The system works by hooking up a capture capture device to the engine's exhaust. The exhaust gas is combined with calcium oxide (aka quicklime) which reacts with the carbon dioxide to produce calcium carbonate (aka limestone). The rest of the “clean” exhaust without carbon dioxide is then released into the atmosphere.

The solid limestone is then brought back to port where it can be sold as a building material. Alternatively, it’s possible to reseparate the material back into calcium oxide, which can be used for further carbon capture, and carbon dioxide, which can be sequestered underground.

There's a lucrative gap in the market for this type of technology. Around 90 percent of traded goods are carried overseas through shipping. As the demand for international freight trade increases, the volume of goods delivered via the ocean is expected to triple by 2050.

Although indispensable to life in the 21st century, the shipping industry pumps out a massive amount of carbon dioxide and other greenhouse gas emissions. Shipping vessels account for 3.1 percent of global carbon emissions per year – that’s more than the sixth biggest nation emitter, Germany. In other words, if shipping were a country, the emissions would be the sixth-biggest in the world.

Seabound says that the shipping industry is way behind other industries when it comes to decarbonization. However, few scientists believe that carbon capture is a silver bullet solution to climate change, despite its best intentions. 

Firstly, no amount of technology can deal with the copious streams of greenhouse gases that end up in the atmosphere. Carbon capture also attracts criticism for being expensive, difficult to scale up, and having a long history of poor performance.

Last but not least, carbon capture can be used as a justification for new fossil fuel projects – or to simply carry on with "business as usual". It’s a bit like treating the symptoms instead of curing the actual disease.

Fundamentally, fossil fuels need to stay in the ground. Until that goal is reached though, perhaps carbon capture technology like this can provide a realistic means to ease the transition towards alternative energy sources.