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South Africa is a carbon-intensive nation, with 89% of the country’s primary energy needs derived from fossil fuels. Given the increasingly intensive global focus on climate change, there is a growing realisation that South Africa is going to need to adopt a lower-carbon energy trajectory, if it hopes to avoid the financial and social penalties that now look inevitable, not only for the developed world, but also for advanced developing countries.
The country emits about 400-million tons of carbon dioxide (CO2) a year, which represents 1% of total emissions on the global scale. And, with the advent of new coal-fired electricity-generating stations and new coal- and gas-to-liquids fuel plants, South Africa’s emissions are likely to rise still further.
But, given South Africa’s abundance of coal and the limitations, and expense, associated with renewables as a bulk energy supplier, much emphasis is being given to clean coal technologies – a point also heavily criticised by many environmental campaigners, who simply believe that the industry will never be able to deliver on its promises.
The immediate focus is on carbon capture and storage (CCS). But, while there is a growing acceptance that the storage of carbon will be commercially viable, possibly by 2016, there is far less certainty on the viability and cost of storage.
That is why a R2-million initiative to develop the ‘South Africa CO2 Storage Atlas’ is potentially interesting. This project will look at identifying existing geological formations for the possible future storage of CO2.
It also has heavyweight support, with State-owned utilities Eskom and PetroSA, diversified miner Anglo American, petrochemicals producer Sasol, and the South African National Energy Research Institute (Saneri) providing financial support for the project. It will use existing geological information to identify potential sites for the possible future storage of CO2. The results of this project will be available in 2010.
In essence, CCS is the process of removing the CO2 produced by hydrocarbon (coal, oil and gas) combustion or processing (for example, gasification) before it enters the atmosphere. Its proponents believe it could reduce up to 90% of the emissions produced from fossil fuels in power stations and industrial facilities, which then could be stored safely underground.
But it is a new technology globally, with any projects that are taking place occurring at a relatively small scale, and there are limited research and development budgets to support the roll-out of prospective projects in developing countries, including South Africa.
THE SA CCS ATLAS
The South African government has declared CCS a national research priority. While South Africa has no obligation, at this stage, to reduce greenhouse-gas emissions, national policy encourages all efforts to mitigate such emissions. South Africa has committed internationally to stabilising emissions between 2020 and 2025.
Saneri asserts that, because of its carbon intensity, South Africa is coming under ever-increasing pressure to decrease emissions and advocates that all options be considered, including CCS.
The draft CCS research coal map (CCSRCM) indicates that significant development work needs to be undertaken before a commercial CCS project could be operational and that such work would be able to produce sufficient information specific to South African conditions that would enable a company to take decisions regarding the implementation of CCS initiatives on a commercial basis.
Saneri senior manager: fossil fuels Dr Tony Surridge tells Engineering News that preliminary studies indicate that South Africa has “genuine CCS potential”.
He says that the country is currently addressing a state of “country readiness” that ensures that enablers are in place to facilitate the implementation of a CCS project. This ‘readiness’ includes identifying and characterising sources and geological storage sites, regulatory systems, plant readiness, and capacity building, which includes technical know-how, human capacity and public outreach.
In other words, CCS is viewed as one element in a larger research and development thrust.
The idea is to provide a framework for research and development efforts, and to support the development of human capacity in CCS, with a stated aspiration of establishing a ‘centre of expertise’ in CCS early this year.
The bigger goal is to facilitate the development of CCS capacity in the country that may be used when possible CCS projects are undertaken around 2016.
WHERE IS THE POTENTIAL?
Surridge points out that preliminary geological studies have highlighted deep saline aquifers that have the potential to store between 4 and 11 times South Africa’s annual sequestrable CO2 emissions for the next 100 years.
He indicates that the Karoo basin and the offshore Mossel Bay are potential sites. “South Africa, unfortunately, lacks natural world-class storage reservoirs, but the onshore central basin in the Karoo Supergroup, with its substantial sedimentary formations, may offer storage opportunities. Offshore sedimentary rocks along the coastline also hold some potential for storage.”
Meanwhile, another report, prepared for the Department of Minerals and Energy (DME) by the Council for Scientific and Industrial Research’s (CSIR’s) manufacturing and materials department, also highlights potential storage hot spots.
Entitled ‘The Potential for Sequestration of Carbon Dioxide in South Africa’, the report indicates that the Great Karoo basin, in the south of the country, has storage potential in terms of the depth of burial and the thickness, and the extent of the basin far outweighs any other basins, such as the Waterberg, Soutpansberg, Tuli or the Springbok flat basins.
State-owned oil company PetroSA is also seeking to estimate the quantities of CO2 that can be safely stored in its producing oil/gas structures of the Mossel Bay offshore fields, once these fields are economically depleted of their hydrocarbons.
The work will be divided into two phases, with the first concentrating on reservoir storage aspects and the second on investigating transportation factors critical to the cost-effective delivery of CO2. Further research will also be pursued, to assess whether there is any possibility to enhance gas recovery off Mossel Bay.
Saneri stresses that the reactions between minerals and CO2 are complex and, to maximise CO2 storage capacity, it is necessary to understand these intricate relationships. Research is required to consider uptake times to achieve 100% saturation, and to determine if different rock types can assimilate CO2 permanently or if it is a long-term temporary storage.
Surridge says that pressure, temperature and time are key factors, which makes this a long-term research intervention, while the role of interstitial water requires consideration.
The CSIR study, meanwhile, also reports that the highly concentrated CO2 streams currently produced by synthetic fuels giant Sasol are well suited for CO2 sequestration, as these streams require little further processing, except for pressuring. It argues, too, that more research is needed to understand the potential for enhancing gas recovery, as well as the potential risks of using exhausted gold and other mines as storage sites.
BIG CHALLENGE
But the CCSCRM says that there are a number of barriers to commercial uptake that need to be dealt with, such as disagreement on the methods that should be employed, with some sectors seeing CCS merely as being aimed at justifying the continued use of fossil fuels.
Conservation agency WWF South Africa’s climate change programme manager, Richard Worthington, tells Engineering News that to claim that South Africa has the potential to store between 4 and 11 times the country’s yearly sequestrable CO2 emissions is a ’spin’, and that it is premature to talk about the potential in any quantifiable sense.
“Far more work is needed, to establish whether we have significant, safe and secure storage potential,” he says.
Then there are the cost implications. According to University of Edinburgh professor of geology Stuart Haszeldine, who was recently quoted on CNN.com, if a new power plant costs about $1,5-billion, it will cost an extra $700 000 to fit capture equipment on the first experimental plants.
Besides capital, financing, resources and penalty costs, estimates indicate that about 30% more coal must be burned for every unit of electricity generated to be dispatched to the consumer, and this cost could be added to the consumer’s electricity bill. Given South Africa’s current electricity supply crisis, and increased tariffs, will consumers be comfortable footing the bill for a better environmental footprint in the future?
Worthington also points out that location appears to be a challenge for CCS in South Africa. There is a view that, if a storage site is not within 300 km of the source, it will be extremely – possibly prohibitively – expensive to pump and pipe the CO2 to its eventual storage location.
“Transportation from the source to the storage site has to be viable, and coal is not always located near the ideal geological setting.”
In addition, one has to consider the materials to be used in the manufacture of the pipeline required to transfer the concentrated CO2. With a liquid-fuel pipeline, any seismic pressure or shift can result in a leakage, which can have disastrous consequences. The type of material used to manufacture the pipe is a concern, given that a plastic pipeline, can, for example, become brittle in time. Then there are the cost implications of changing a pipeline if materials, for example, have a life span of 20 years.
Worthington points out that there is also a lot of uncertainty about the regulatory regime to govern CCS in South Africa, and that, even if a geological site was found, there is no legislation indicating how one would secure the rights to go about using it.
TRANSITIONARY TECHNOLOGY
Worthington says that South Africa should not consider CCS as the only option in reducing CO2 emissions.
The WWF proposes that what is needed is the expansion of energy efficiency in industry, buildings and all forms of transport to stabilise the overall energy demand by 2025; to increase the use of renewable energy sources, such as wind, hydro, solar and thermal, and bioenergy; and the phasing out of remaining emissions from conventional fossil fuels used for power and industrial processes, with CCS playing a transitional role in achieving carbon-neutral energy supply.
“There is no other reason for storing carbon underground in South Africa than to avoid emitting it, because we don’t have significant oilfields that could be used for enhanced oil recovery. So the question is, ‘What are the alternatives?’ End of pipe is never the best way to approach any pollution problem,” says Worthington.
He also asserts that, if CCS has to compete against renewables for State funding, “we would be shooting ourselves squarely in the foot if we are investing in the assumption that we are going to go on polluting to end of pipe, rather than investing in renewable electricity generation”.
This is based on the fact that renewable energy also avoids local pollution, can create more employment through the creation of a local renewables industry, and that the electricity system can be decentralised, which makes it more robust for the future.
THE ‘BIG’ NO
Environmentalists are wary about CCS, with a primary concern being that the huge capital investment required for CCS does not dominate or crowd out the investment in short-term solutions and renewable energy.
One high-profile opponent is Canadian scientist Dr Patrick Moore, who says that CCS is not economically or technically feasible.
Moore previously told Engineering News that CCS is a “huge technical problem”, and that, given the massive volumes of gas, all feasible approaches would end up using a large portion of the energy of the power plant for sequestration.
Given that CO2 will be pumped into coal-, oil-, gasfields, or old mines, how certain is mankind that all seals will be securely sealed, of the ever changing structure of the earth, and of addressing the greatest concern of human error?
“The insurance industry is not very excited about it because they are afraid that the CO2 might come back to the surface and asphyxiate people” he says.
And while the technique of oceanic storage appears reasonably well tested internationally, research into the energy and financial costs and environmental effects must be probed further.
An increase in dissolved CO2 in water can result in an increase in the acidity of water, with all organisms with calcium carbonate in their metabolism being affected. Further, the larger parts of the oceans are not part of national territory and the large-scale sequestration of CO2 will need to be agreed upon by many governments.
GLOBAL OUTLOOK
So, where do things stand? Small-scale CCS projects are being undertaken globally. Trials are under way in Norway, Algeria and Australia, while China plans to test its first postcombustion capture technology in Beijing.
The United Nations (UN) climate change talks in Poland last month resulted in the International Energy Agency calling for 20 carbon-capture projects to be built. CCS is part of the UN’s strategy to halve global emissions of global-warming gases by 2050.
But CCS will only be made viable in South Africa, and in the rest of the world, if governments give greater urgency to the issue of regulatory regimes.
But there is also a strong view that government and energy stakeholders should not place all their eggs in the CCS basket, but rather see it as one of a range of the technology solutions that should be pursued to reduce the world’s carbon footprint.
The success of CCS in South Africa will also be dependent on the degree of confidence the scientific community has in its potential for storage. This, in turn, will hinge on the development of the human capacity needed to truly understand the risks and opportunities.
If the Carbon Atlas project achieves little more than helping us to gain such insight and build that human capacity, it would have been worth every cent, but then, do we have the luxury of waiting to ‘significantly’ reduce the country’s carbon footprint till possible commercial implementation of CCS in 2016?
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