South Africa’s Centre for Carbon Capture and Storage (CCS), which was opened on March 27, will start working towards its vision of having a CCS demonstration plant operational in South Africa by 2020.
South African National Energy Research Institute senior manager, and acting CEO of the CCS centre Tony Surridge explains that the centre’s mission will be to develop South African human and technical capacity to undertake this envisioned demonstration plant. A preliminary to the demonstration plant will be a test injection of carbon dioxide into local geological formation, which he says will likely be similar to the Otway project in Australia.
The main concern for the centre, as it ramps up in 2009, will be to assess the regulatory system in South Africa so as to facilitate CCS from a legislative aspect. Much legislation exists in South Africa regarding the extraction of minerals from the ground, however injecting them back into the earth is a different matter altogether. Also on the agenda is the work on a business plan for the carbon dioxide injection test, as well as appointing a Chair in geological storage.
The CCS centre will be officially launched in September 2009 at the CCS conference, which will be held at the same time.
More than just technology, the major issue that must be addressed in South Africa at this stage is the geology. Scientists will need to see how stored carbon dioxide reacts with South African formations. “We need to put carbon dioxide into South African rocks and see how the rocks react,’ explains Surridge.
The centre will be fully operational in 2010, and the aim is to have a carbon dioxide geological storage atlas for South Africa complete by April 2010. This will depict sites suitable for the storage of the carbon dioxide.
Once the CCS Atlas is complete by 2010, work will start of the carbon dioxide geological injection test, which is set for completion by December 2016, following that, the next goal is the demonstration plant to be up and running by 2020.
The CCS centre will have a number of issues to continually work on before the demo plant is ready, and these include public outreach, legal, capture, economics, transport, storage, monitoring and verification, and remediation considerations. All this would need to be done with constant input from the international CCS community.
At present, CCS technology is successfully used for enhanced oil recovery. Geological formations in which carbon dioxide can be stored are depleted oil and gas fields, deep saline aquifers, and unmineable coal seams.
Surridge is not in favour of storing carbon dioxide in unmineable coal seams as he says that what is considered unmineable today, could be mined in the future.
Surridge says that the carbon dioxide must be injected to levels below 800 metres from the surface. At these levels the carbon dioxide is compressed and becomes a supercritical fluid.
Allaying fears of CCS leaks, Surridge notes that it is unlikely that leaks will occur, but even if they do, they will be slow leaks that could be re-sealed. There is also no risk of explosion, as with methane.
Because significant research on South African geology exists, it is estimated that there is potential storage capacity in the region of 287gigatons in deep saline aquifers found below the Free State, KwaZulu-Natal and Lesotho. If one omits the upper layer, which may be too shallow, then the calculated potential storage capacity falls to 104Gt of capacity.
Reacting to climate change, South Africa’s long-term mitigation scenario (LTMS) punts CCS as an important way for South Africa to significantly reduce its greenhouse gas emissions. The LTMS calls for a possible capture and storage of about 5% of the country’s carbon dioxide emissions.
Surridge explains that if South Africa was to do this and stored about 40Mt/y of carbon dioxide for 100 years, about 4Gt of storage capacity would be required. This means that the country potentially has more than enough storage capacity.