Carbon Capture and Storage (CCS) is a method to capture point source carbon emissions from industrial facilities or power generation stations thereby preventing them entering the atmosphere. It can be combined with other technologies to result in negative emissions. CCS allows for reducing the GHG emissions from electric power generation while renewable energy resource integration ramps up. In the industrial sector where decarbonization through the integration of non-fossil energy resources is currently technologically and economically challenging, CCS may provide a bridge in the decarbonization path (C2ES).
CCS is achieved through 1) capturing carbon at point sources, 2) transporting the captured carbon, and 3) storing the captured carbon over the long-term in sub-terrestrial reservoirs (CCS Association). Carbon capture can be achieved through post-combustion capture, pre-combustion capture or through oxy-fuel combustion. The captured carbon is transported via pipelines or freight ships to carbon storage sinks. Captured carbon must then be stored permanently in one of three ways: in underground rock formations (“geo-sequetration”), deep oceans, or as mineral carbonates (IPCC, 2005).
Captured carbon dioxide can also be repurposed towards carbon-based products, also known as carbon dioxide utilization or CO2U (ICEF, 2017). Captured carbon dioxide could be used as the base chemical component or additive in the manufacturing of building materials, fuels, carbon-based chemicals such as methanol, ethanol etc., polymers and carbon reinforced composite materials. The International Cool Earth Forum elaborates on various CO2U techniques in their 2017 report.
There are a few notable barriers to the sustainable adoption of CCS at scale (Budinis et al., 2018):
- Costs – Depending on the method, CCS would cost anywhere between $25 and $130/tCO2 abated (Global CCS Institute, 2017). Without financial incentives like carbon pricing or subsidies, facility owners have limited incentive to invest in CCS systems.
- Storage – Geo-resource availability, location, and reliability – Geological carbon sequestration limits are estimated to be between 600-2000 GtCO2 cumulatively by 2100. In addition, storage resources are not distributed equally across the globe. Some geologic structures can have leakage issues (Ajayi et al 2019). Deep ocean sequestration likely has negative effects on ocean fauna. Mineral sequestration processes are very slow at ambient conditions and require a significant amount of energy to be accelerated.
- Commissioning bottlenecks – There is a significant amount of time that goes towards appraisal, equipment selection, and installation of CCS infrastructure. Time delays can discourage CCS investments by facility owners.