What is carbon capture and storage?

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

The term carbon capture and storage is also known as carbon dioxide capture and storage.

It’s a three-step process, involving: capturing the carbon dioxide produced by power generation or industrial activity, such as steel or cement making; transporting it; and then storing it deep underground.

What is the need of carbon capture and storage?

The Intergovernmental Panel on Climate Change (IPCC) highlighted that, if we are to achieve the ambitions of the Paris Agreement and limit future temperature increases to 1.5°C (2.7°F), we must do more than just increasing efforts to reduce emissions – we also need to deploy technologies to remove carbon from the atmosphere.

CCS is one of these technologies and can therefore play an important role in tackling global warming.

How does CCS actually work?

There are three steps to the CCS process:

I . Capturing the carbon dioxide for storage

The CO2 is separated from other gases produced in industrial processes, such as those at coal and natural-gas-fired power generation plants or steel or cement factories.

II . Transport

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

III . Storage

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

Where are carbon emissions stored in CCS?

Possible storage sites for carbon emissions include saline aquifers or depleted oil and gas reservoirs, which typically need to be 1km or more under the ground.

As an example, a storage site for the proposed Zero Carbon Humber project in the UK is a saline aquifer named ‘Endurance’, which is located in the southern North Sea, around 90km offshore. Endurance is approximately 1.6km below the seabed and has the potential to store very large amounts of CO2.

What is Carbon Capture, Utilisation and Storage (CCUS)? What is the difference between CCUS and CCS?

The terms CCS and CCUS (Carbon Capture, Utilization, and Storage) are often used interchangeably.

The difference between the two is the specified ‘utilization’ of the captured carbon and refers to its use for other applications, such as enhanced oil recovery (EOR), potentially making liquid fuel, or the manufacturing of useful consumer goods, such as plastics.

Since both approaches capture emitted CO2 and effectively store it, whether that be under-ground in geological formations or long-term trapping in material products, the two terms are often treated the same.

Is storing carbon as part of CCS safe?

CCS is a proven technology that has been in safe operation for over four decades.

Where is CCS being used already and what’s in development?

According to the Global CCS Institute’s 2022 report, there were 194 large-scale CCS facilities globally at the end of the year – compared to 51 in 2019 . 30 of these projects are in operation, 11 under construction and the remainder in various stages of development.

Of the total number of projects, 94 were in the Americas (80 in the U.S.), 73 in Europe (27 in the UK), 21 in Asia-Pacific and 6 in the Middle East.