José de J. Díaz

INFLUENCE OF PRESWELLING ON THE BURNING PROFILE OF COAL

Publisher Summary This chapter describes the influence of pre-swelling on the burning profile of coal. A burning profile is a plot of the rate at which a sample of coal burns under standard conditions. Good correlations have been found between the characteristic temperatures of the profiles and the combustibility of the burning coal. It has been demonstrated that fuels with similar burning profiles behave in a similar manner, so burning profiles provide a valuable, rapid method of ranking coals in terms of their burnout performance. Some coals show various peaks and shoulders in the combustion profile curve before the peak temperature is reached. The peaks and shoulders are because of a sudden change in the rate of weight lost and are completely absent in the parent THF swollen-coal. The peaks present in the unswollen coal are because of the pyrolysis of trapped molecules between the coal pores. When these pores are opened by swelling, the trapped molecules are released; therefore, the burning profile of these swollen coals does not show these peaks.