Combustion of Spanish coals under simulated pressurized-fluidized-bed-combustion conditions

Coal reactivity is an important parameter related to efficiency of boilers, and learning how to predict it can reduce costs when screening for new fue ls. We have measured the reactivity of Spanish coals in a high pressure the rmogravimetric analyzer, under operational conditions similar to those foun d in Pressurized-Fluidized-Bed-Combustion (PFBC). The results obtained from non-isothermal tests were used to look for correlations between the reacti vity and the physical and chemical properties of the coals. Reactivity incr eased with increasing rank, but no relationship was found with the initial pore or surface characteristics of either the coals or the chars. We found a correlation between the true density of the chars and their reactivity. W e also observed a decrease in the reactivity, calculated from isothermal te sts, as the pressure was increased, while there was a slight increase in re activity with increasing temperature. (C) 1999 Elsevier Science Ltd. All ri ghts reserved.