While using circulating fluidised bed (CFB) technology to generate energy from waste coal was a relatively new concept in South Africa, Rainbow Millennium Power Company director Hugo Stewart said on Tuesday that there was huge potential for this technology.

The company was working in partnership with other companies to establish a 270-MW CFB plant in Richards Bay, which could be increased by a further 270 MW.

Speaking at a cogeneration conference in Johannesburg, Stewart explained that CFB was a clean-coal technology that was well known overseas. There were about 1 000 CFB plants worldwide, with about 70 GW of electricity being generated.

Stewart said that about 40% of South African coal was not exported, while a portion of this also was not used by Eskom in its coal-fired power stations owing to its quality.

He explained that there was a large resource of low-cost discard coal in South Africa.

Not only could the CFB plant use waste coal to produce electricity, which would benefit the nearby smelters, it could also be used to beneficiate ash for use as a cement by-product, landfill material and for agricultural lining uses.

Stewart noted that the plant could also use ash as a fuel resource.

However, in order for the plant to successfully use ash, it would include at least 10% of biogas.

The plant, which is known as project Umbani, would source one-half of its waste coal and fuel sources from Witbank and the other one-half from the surrounding KwaZulu-Natal (KZN) area.

Construction of the plant was expected to start in April next year and would come on stream in July 2012. The project developers were, however, still awaiting the outcome of Eskom's Pilot National Cogeneration Programme bid.

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