Clean coal technology
Clean coal technologies such as ultra supercritical (USC) Powdered Coal, atmospheric and pressurised fluidised bed combustion (AFBC and PFBC), and integrated gasification combined cycle (IGCC) plants are now accumulating commercial experience. These methods of generation essentially offer higher thermal efficiencies and hence produce lower emissions per MW. The main competitors are conventional PC plants and combined cycle gas turbine plants (CCGTs).
Natural gas fired combustion turbines and CCGT plants have dominated the recent power generation markets in much of Europe, particularly the UK and in the US and Japan. However, concerns over natural gas price spikes and medium to long term availability have led governments and power companies to initiate studies and projects on clean coal technologies as a strategic hedge against over-reliance on natural gas alone to provide future power needs.
The greatest uncertainties for future coal plants are the environmental requirements for reduction in SOx, NOx and CO 2 emissions. USC PC plants do offer reductions in emissions over conventional sub-critical units pro-rata with the associated efficiency gains, but the effect on CO 2 emissions would be modest at approximately 6 percent. As currently estimated, the costs of CO 2 removal from PC plants are about double those from IGCC plants. As and when governments' regulations require CO 2 removal to a major extent, then natural gas prices will most probably rise and IGCC would most likely become the preferred clean coal technology.
TWI can help with the developments that are required to address reliability and maintenance issues associated with materials and coatings for hot gas path parts in the gasifier and turbine of the IGCC plant.
For further information, please contact: power@twi.co.uk
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