Carbon Capture Explained

Carbon Capture and Storage (CCS) is a way of reducing carbon emissions, which could be key in helping to tackle global warming.

It follows a three step process:

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Step 1. Capturing the carbon dioxide for storage

The CO2 is separated from other gases produced in industrial processes, and then captured.

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Step 2. Transport

The CO2 is then compressed and transported via pipelines, road transport or ships to a site for storage.

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Step 3. Storage

Finally, the CO2 is injected into rock formations deep underground for permanent storage.

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CCS technology is still relatively new, and there are a number of different ways of capturing and storing CO2. But the basic principle is the same: to keep carbon dioxide out of the atmosphere and so help reduce greenhouse gas emissions.

One example of CCS in action is at the Sleipner natural gas field in the North Sea, where since 1996 around one million tonnes of CO2 have been injected into a saline aquifer each year.

In another project in Weyburn, Canada, CO2 from a coal-fired power plant in North Dakota is being used to help extract oil from an ageing oilfield. The CO2 is injected underground, where it acts like a solvent, helping to bring the oil to  the surface.

CCS is a promising technology, but it faces a number of challenges. One is the cost – CCS can add around 30% to the cost of power from a new coal-fired power plant.

Another challenge is finding suitable sites for storage. In many cases, the best storage sites are located far from where the carbon dioxide is produced. This means that transport costs can be high.

And finally, there are concerns about the long-term safety of storage – what happens if the CO2 leaks out?

Despite these challenges, CCS could play an important role in helping to tackle climate change. And with governments around the world looking for ways to reduce emissions, it's likely that we'll  see more CCS projects being developed in the years to come.