Global warming: Sasol’s power station in Secunda. SA generates more than 400-million tonnes of CO² a year. Picture: ANTONIO MUCHAVE
Global warming: Sasol’s power station in Secunda. SA generates more than 400-million tonnes of CO² a year. Picture: ANTONIO MUCHAVE

In a remote corner of northern KwaZulu-Natal close to the Mozambique border, SA is getting ready to start dumping its growing cloud of climate-changing carbon gas emissions.

The plan is to dig an underground well in the sandy rock formations south of Kosi Bay and Tembe Elephant Reserve and inject an initial 50,000 tonnes of carbon dioxide into the earth — in the hope that the gas will stay there, locked up forever.

To save on drilling costs, the hole would have to be at least 800m deep, though it might go down to about 2km to locate a suitable rock formation.

If the pilot project is successful, the experiment would be repeated on a grander scale in the seabed somewhere between Durban and Richards Bay — allowing Eskom and other large industrial operations to carry on burning coal and other fossil fuels for decades.

The plans were confirmed at a conference in Durban in October, organised by the Department of Energy and South African Centre for Carbon Capture and Storage.

Noel Kamrajh, manager of the CO² storage demonstration project, said that seismic tests and pilot drilling projects were due to start soon: "We are looking at 2019 to put the first CO² into the ground."

He said the project depends on locating a permeable and porous rock formation, and a capping rock formation to prevent leakages to the surface.

Drilling tests by state-owned company Soekor in the 1970s and 1980s suggested that there could be suitable sites in areas known as the Kosi Trough and Bumbeni Ridge.

"We are not looking for a big cavity in the ground, but rather sandstone formations that act almost as a sponge," Kamrajh said. The site would be monitored to test whether the injected carbon was migrating underground or leaking to the surface.

Norway has been doing similar storage for just more than two decades, separating and capturing millions of tonnes of carbon dioxide from offshore oil and gas wells and pumping the purified CO² back underground into sandstone below the North Sea.

SA generates more than 400-million tons of CO² a year, mainly from Eskom’s coal-fired power stations, fuel refineries, cement-making and other heavy industry.

Eskom is the biggest "climate gas polluter" in Africa and produces more CO² [on a per capita basis] than China, Brazil or India — though SA contributes roughly 1% of global greenhouse gas emissions.

Because underground storage in a geological setting had not been tried in SA before, it was essential to develop new laws, policies and research studies to deal with the risks and uncertainties

While CO² is not toxic at low levels, it can asphyxiate people exposed to large volumes — in 1986 at least 1,700 people and 3,500 animals died after a concentrated cloud of volcanic CO² gas bubbled to the surface of Lake Nyos in Cameroon.

Norwegian ambassador to SA Trine Skymoen insisted that the technology — pioneered at the Sleipner gas fields in the North Sea — had operated "safely" for 20 years, allowing Norway’s Statoil oil and gas company to dodge carbon emission taxes and to explore opportunities to dump carbon generated by other countries.

Through the World Bank, Norway and the UK have been significant benefactors to the South African Carbon Capture and Storage research project, with Norway contributing more than R1m each year in 2009-14.

In 2014, the World Bank’s Carbon Capture and Storage Trust Fund announced further global allocations of $49m for projects — with SA allocated the largest slice of $27m.

Skymoen claimed that carbon capture and storage could bring down the costs of reducing global CO² emissions by 138%, a more optimistic estimate than UK climate finance chief Peter Warren, who estimated it could be 40% more expensive to curb global greenhouse gas emissions without capture and storage.

Senior KwaZulu-Natal government environmental official Zama Mathenjwa seemed cautious about the carbon experiment.

How would carbon dioxide be captured and separated from other chimney stack emissions, including more noxious chemical compounds that might also end up underground? he asked.

Mathenjwa also asked whether it was possible that carbon emissions would leak back into the atmosphere or into other rock formations with complex chemistry.

Because underground storage in a geological setting had not been tried in SA before, it was essential to develop new laws, policies and research studies to deal with the risks and uncertainties.

KwaZulu-Natal MEC for economic development, tourism and environmental affairs Sihle Zikalala said his government had given the green light for feasibility studies and exploration to go ahead, but that final approval would depend on further investigation.

University of Cape Town environmental law expert Prof Jan Glazewski has questioned whether CO² emissions from major industry should be classified as waste (or hazardous waste) and be regulated accordingly.

He asked who carried the can if the brown stuff (much like acid mine drainage from Gauteng’s gold mines) should hit the fan, tens or hundreds of years later — taxpayers or private carbon generators?

Namisha Muthraparsad, a senior scientist from the Department of Water and Sanitation said SA was the world’s 30th-driest country.

Noting that CO² was mildly acidic and could generate carbonic acid when mixed with water, she asked whether it would ever be possible to rehabilitate diminishing surface water and groundwater resources if there were pollution through underground geological pathways.

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