Circulating fluidised-bed (CFB) technology was the way of the future, owing to the availability of large amounts of discard coal and a worldwide move towards using lower-grade fuels, power technology group Alstom steam business regional sales director Hugh Kennedy said at a Fossil Fuel Foundation fluidised-bed combustion (FBC) and gasification workshop held in Johannesburg last week.
The key driver for choosing a CFB boiler was its ability to efficiently burn a wide range of fuels while meeting low emissions requirements.
Reduced sorbent and water consumption compared with that of pulverised coal plants, and the ability to deal with corrosive fuel constituents while still meeting local regulations made the choice of a CFB boiler-based power plant particularly attractive.
“New power plants to be built in India and China are being designed to require lower grades of coal and, as a result of a spike in the coal price a few years ago, many countries are also considering alternatives to burning imported coal for power generation,” Kennedy stated.
The use of other forms of fuel, such as biomass, was also being considered, which made CFB a logical choice, as it could burn a wide variety of fuels, he added.
Also speaking at the workshop was drying, cooling and calcimining installation design and supply company Scientific Design MD Thierry Johannes, who agreed that the ability to use multiple forms of fuel was a significant advantage of FBC.
“Fuels that can be used in FBC include low-ash and high-ash coal; anthracite; peat; biomass; digested waste; sludge, such as that from furnaces or paper mills; combustible gases; liquids; and waste streams, which could comprise solids, gases or liquids that contained carbon or hydro- carbons,” he explained.
Further, FBC also had a high combustion efficiency of between 95% to 98%.