Characterisation of coal blends for pulverised fuel combustion

This study evaluates the effect of blending on the combustion characteristics of pulverised coal through the testing of six coals and fifteen coal blends in an isothermal plug flow reactor (IPFR). The aim of the test was to assess whether the combustion behaviour of blends could be predicted from that of the parent coals. For blends of bituminous coals, an additive behaviour was found for ash, volatile matter and calorific value. Other non-standard fuel properties such as the high volatile matter content determined using the IPFR, fuel-N release and char combustion, were found to be additive. The blends of bituminous coals and lignite demonstrated non-additive properties as far as volatile matter release is concerned. It was concluded that the inorganic coal phase is responsible for non-additive behaviour in blends, since the volatile components of the coal mineral matter may undergo reactions with the second blend partner.