Mathematical modelling of circulating fluidized bed reactors by reference to a solids decomposition reaction and coal combustion

Abstract Commercial-scale circulating fluidized bed (CFB) reactors have been in use for several years for processing fine-grained solid materials in non-catalytic gas/solid reactions. Recently they have also been employed successfully for the combustion of carbon-containing fossil fuels and/or residues for power generation. Despite these numerous industrial applications, theoretical knowledge of CFB operation still lags behind. The present paper covers modelling and simulation methods for the description of steady- and unsteady-state operating conditions in CFBs. The validity of the simulation method is demonstrated by a comparison of simulation results with empirical data for two different reactions: the relatively simple thermal decomposition of NaHCO 3 , and the complex combustion of coal for power generation. Results such as reactor temperatures, flue gas analyses, pollutant emissions and heat flows are presented. Acceptable agreement between measured and calculated data was found.