CCS: What is carbon capture and storage – and how does it work?

The National

3 days ago

The project, near Peterhead, has been a long-standing point of contention between Labour and the SNP – who hit out at the UK Government both in October last year and April this year after it was repeatedly passed over for funding.
Here, we take a look at what carbon capture and storage is, how it works, and why it's controversial.
What is CCS?
Carbon capture and storage is the process of catching carbon dioxide (CO2) as it is emitted from a power station or factory, preventing it from going into the atmosphere, and then storing it underground.
It works only for CO2 and not other greenhouse gases such as methane or nitrous oxide, though CO2 is the most problematic as it stays in the atmosphere for centuries, locking in long-term warming.
Current technology captures around 90% of CO2 emitted, but this is expected to increase.
How does carbon capture work?
CO2 is captured at source, compressed and liquified and then taken to caverns underground or beneath the sea where it is injected down to a depth of hundreds of metres.
Empty oil and gas reservoirs can be used if the geology is appropriate and companies are planning to use their extraction rigs to pipe down liquid CO2.
It is hoped CCS will capture eight billion tonnes of CO2 globally by 2050.
Will it help stop climate change?
It may, to an extent. CCS technology is not yet developed enough to balance CO2 emissions this decade; only deep and rapid emissions cuts can prevent the Earth heating beyond 1.5C of pre-industrial average temperatures, scientists have said.
CCS will be needed in the long term, however, as some industries such as cement-making are almost impossible to run without fossil fuels and will need a more mature CCS industry to balance out emissions.
The climate change committee, which plans the UK Government's net zero path, has said CCS is necessary but it must also be coupled with a decline in fossil fuel production.
Direct air capture is another form of CCS to take CO2 directly out of the atmosphere, though this process is currently too expensive and energy intensive to be useful at the scale needed.
Where is CCS being used?
There are about 45 CCS projects in operation around the world. CCS has been in operation since 1972 in the US, according to the energy firm National Grid.
CCS plants are generally in highly industrialised areas, which should reduce the need to move captured CO2 over long distances.
The International Energy Agency states: 'Around 45 commercial facilities are already in operation applying carbon capture, utilisation and storage (CCUS) to industrial processes, fuel transformation and power generation.
'CCUS deployment has trailed behind expectations in the past, but momentum has grown substantially in recent years, with over 700 projects in various stages of development.'
The British Geological Survey has published an analysis of where it believes CCS could work best.
Why is CCS so controversial?
CCS is not short of opponents, with the normally disparate Greens and Reform UK both opposed to its deployment.
Many environmentalists see it as an excuse for the fossil fuel industry to maintain production and profits instead of cutting back to save emissions, hoping CCS technology will eventually mature.
It is still too early for CCS to make any significant contribution to lowering greenhouse gas emissions, with no guarantee it will eventually mature, and scientists have said that demand for high-carbon industries must fall in the absence of sustainable technology.