Carbon capture and storage in South Africa

Submitted by: Amanda Botes, Thursday, May 17, 2012

Carbon capture and storage is included in the National Climate Change Response White Paper as part of the South African government’s mitigation strategy to decrease its carbon emissions by 34% by 2020. This article describes the development of a Carbon Capture and Storage Roadmap for South Africa and provides more information on carbon capture and storage.  

 

The roadmap, developed by the South African Centre for Carbon Capture and Storage (SACCCS) maps out five stages leading up to the development of a commercial carbon capture and storage plant by 2025.

South African Carbon Capture and Storage Roadmap

The five stages of the roadmap include:

  1. A preliminary investigation into carbon capture and storage potential in South Africa
  2. Development of a geological atlas identifying potential sites for carbon capture and storage
  3. COinjection experiment (2017)
  4. Demonstration plant (2020)
  5. Commercial plant (2025)

At this stage phase one and two have been completed. Planning has begun for the implementation of the third step of the roadmap, to test injecting carbon dioxide into underground storage cavities  to determine if carbon capture and storage is technically feasible in South Africa.  It is expected that a test site will be up and running by 2017.

What is carbon capture and storage?

Carbon capture and storage, also referred to as carbon capture and sequestration, involves capturing carbon dioxide released from large industries and storing it underground.

There are four major steps in the process:

  1. Capture: Large amounts of carbon dioxide and other gases are released when fossil fuels are burned for energy generation. Carbon capture involves separating the carbon dioxide from the other gases at large industrial plants.
  2. Transport: After the carbon dioxide has been separated from the other gases it would then be compressed and transported via pipeline to a storage site. The compressed carbon dioxide could also be transported in containers via land transportation.
  3. Storage:  The compressed carbon dioxide would then be injected in rock formations deep underground at depths above 1 kilometre. Potential sites for carbon storage include saline aquifers, depleted oil and gas reservoirs, and deep unmineable coal seams. Carbon could also be stored offshore.
  4. Monitoring: After the carbon dioxide has been injected it would need to be monitored.

Advantages of carbon capture and storage

Electricity generation plants, coal-to-liquids plants and cement manufacturing plants are large emitters of carbon dioxide and proponents of this technology believe that a large percentage of these emissions can be prevented from reaching the atmosphere through carbon capture and storage technology.

Disadvantages of carbon capture and storage

Disadvantages highlighted by Opponents of the technology include:

  • Carbon capture and storage technology is expensive and may divert funding away from other climate change mitigation and adaptation projects that have other environmental benefits.
  • Carbon capture and storage requires large amounts of energy which detracts from the mitigation impact of carbon capture and storage.
  • Safe storage underground of carbon cannot be guaranteed and there are risks that the CO2 could leak out from underground influencing climate change at a later date.   In addition leaks pose risks on natural ecosystems and groundwater systems.

Other examples worldwide

According to the Global CCS Institute, there are eight large scale carbon capture and storage projects in operation worldwide.  These are found in Norway, USA, Canada, and in Northern Africa. The USA, Canada, China, South Africa, Australia and many countries in Europe are investing large amounts of money and time into researching and identifying suitable storage site for CO2.

 

Amanda Botes