What is CCS?
Carbon capture and storage (CCS), which is sometimes called carbon capture and sequestration, prevents large amounts of carbon dioxide (CO2) from being released into the atmosphere. The technology involves capturing CO2 produced by large industrial plants, compressing it for transportation and then injecting it deep into a rock formation at a carefully selected and safe site, where it is permanently stored.
Because CCS can achieve significant CO2 emission reductions, it is considered a key option within the portfolio of approaches required to reduce greenhouse gas emissions.
CCS technology involves three major steps:
The separation of CO2 from other gases produced at large industrial process facilities such as
coal and natural gas power plants, steel mills and cement plants.
Once separated, the CO2 is is compressed and transported, usually via pipelines, to a suitable
site for geological storage.
CO2 is injected into deep underground rock formations, often at depths of one kilometre or more.
Why do we need CCS?
The amount of CO2 in the atmosphere is increasing and the temperature of the Earth is rising. To
avoid dangerous climate change, the global average temperature rise must be capped at 2ºC relative to pre-industrial times. To achieve this, we need a very significant scale of CO2 mitigation.
CCS can contribute around 14% of total energy-related CO2 reductions by 2050, compared to a ‘do nothing’ approach (2014, IEA, Energy Technology Perspectives).
Around 40% of CO2 emissions come from the power sector. Another 25% come from large-scale industrial processes such as iron and steel production, cement making, chemicals and refining.
Demand for fossil fuels is likely to remain strong, especially in developing countries, where a significant percentage of the population currently has no access to electricity.
CCS is a viable option – in some cases, it is the only viable option – for significantly reducing emissions from suchlarge-scale emission sources.
A portfolio approach
Renewables, like CCS, are an important part of a sustainable clean energy portfolio. However, given the large, easily accessible, low-cost reserves of fossil fuels available, they will continue to be used to generate power and support industry for many decades to come.
The Global CCS Institute advocates for CCS as one option that can stem CO2 emissions as the world transitions to a new energy future.