Carbon capture and storage (CCS) is an increasingly popular method used for carbon sequestration, the long term storage of carbon dioxide. It aims to capture, transport and securely store up to 90% of CO2 emissions from both industrial and municipal activities 1. There are many ways of capturing carbon but which carbon capture solutions are best?
Carbon dioxide (CO2) levels are higher than ever today. For instance, in 2018 CO2 amounted to 407.4 parts per million of atmospheric gas, a significantly high amount. We have seen some of the impact of a warming climate under increasing fossil fuel use, and as citizens we need to look towards innovative and sustainable methods to resolve this global issue2.
Carbon Capture Chain
CCS technologies, transportation and storage form the three stages of CCS. Bedrock and unused oil fields are used to store carbon.
The Three Stages of Carbon Capture and Storage Technology
Post-combustion process acts as a carbon cleaner mechanism. Combusting CO2 is extracted, or captured, from flue gas.
Pre-combustion involves reacting steam and air with the fossil fuel to produce syngas, or synthetic gas. Syngas is a mixture of carbon monoxide and hydrogen. A shift reactor separates the syngas.
Oxy-fuel combustion forms the last stage of the process, and involves the internal production and cooling of flue gas. As a result, water vapour and compressed CO2 remains.
Generally speaking, the technology of carbon capture is ready to go. Many carbon capture companies have even started offering services. The problem with CCS is that it doesn’t really have a destination.
The other problem arise in the pre-existing and old power plants. Post-combustion would need to use about 40% of a power station’s energy. Retrofitting is a solution, however, it would incur a charge of around £1 billion per power plant3.
There are many innovative and progressive solutions to carbon capture.
Tree planting offers a more sustainable approach to carbon sequestration and the use of artificial trees could prove even more effective.
Coal storage combined with biomass use proves to be a carbon-negative approach 4.
Another CCS method involves the absorption of CO2 using seawater where carbon is locked deep into the ocean bed. Although certainly innovative, this ocean sequestration method has proved to be less efficient.
- Carbon Dioxide Capture and Storage. Intergovernmental Panel on Climate Change. https://www.ipcc.ch/site/assets/uploads/2018/03/srccs_wholereport-1.pdf. Accessed November 2, 2020.
- Greenhouse gas concentrations in atmosphere reach yet another high. WMO. https://public.wmo.int/en/media/press-release/greenhouse-gas-concentrations-atmosphere-reach-yet-another-high. Published November 25, 2019. Accessed November 2, 2020.
- Carbon Dioxide Capture and Storage. IPCC. https://web.archive.org/web/20131101215706/http://www.ipcc.ch/pdf/special-reports/srccs/srccs_technicalsummary.pdf. Accessed November 2, 2020.
- Gasification of coal and biomass as a net carbon-negative power source for environment-friendly electricity generation in China. PNAS. https://www.pnas.org/content/116/17/8206. Published April 23, 2019. Accessed November 2, 2020.