What is Carbon Capture and Storage (CCS)?
Article | Last updated: 13/10/2021 | Ministry of Petroleum and Energy
Why Carbon Capture and Storage (CCS)?
CCS is short for carbon capture and storage and refers to the capture, transport and storage of CO₂. Carbon capture, utilisation and storage, or CCUS, is another term that is widely used. With CCUS, the CO2 is utilised. CCS is a tool to limit the amount of CO₂ emitted into the atmosphere by capturing CO2 and thereafter storing it safely, for example in underground geological formations. The Global CCS Institute (GCCSI) operates a database that shows the number of CCS projects that are currently in operation and under construction.
CO₂ can be captured from flue gases, from power plants and industrial processes. CO₂ is a natural component in natural gas. CO₂ can be separated from the rest of the natural gas as part of the gas treatment process needed in order to achieve the necessary quality before the gas is shipped to customers by pipeline or ship. Capturing CO₂ from low pressure flue gases from power plants or industrial processes is more difficult and energy intensive than capturing CO₂ from high pressure natural gas.
There are several different technologies available for capturing CO₂ from flue gases and several of these are currently being tested at the Technology Centre Mongstad (TCM). More information about different capture technologies can be found at the Gassnova webpages.
CO₂ can be transported in pipelines or in tanks on ships, trains and trucks. The best alternative generally depends on the amount of CO₂ to be transported and the distance between capture site and storage facility. Transport by ship is typically favourable for smaller amounts of CO₂ and fairly long distances and provides great flexibility. Pipeline transport is normally more suitable for larger amounts of CO₂ and shorter distances.
It is possible to safely store large amounts of CO₂ on the Norwegian continental shelf. In Norway we are only planning for CO2 storage offshore below the sea bed. On the continental shelf we have access to large geological formations of depths where favourable pressure and temperature conditions, amongst other conditions, prevent CO₂ from migrating through layers of sand and rock towards the surface. The Petroleum Directorate has developed a storage atlas that gives an overview of possible storage locations on the Norwegian continental shelf. According to the atlas, there is a storage capacity of more than 80 billion tonnes of CO2 on the Norwegian continental shelf.
CO2 can also be used in other industrial processes as an input factor. The use of CO2 as an input factor in industry will in many cases not result in permanent storage, but only postpone emissions. The use of CO₂ for enhanced oil recovery (EOR), on the other hand, is one of the areas of use where the majority of used CO₂ can be stored permanently.
You can read more about Norway's work on CCS here.