The elementary and proximate analysis, calorific values, DTG
and DSC curves showed remarkably differences between coal,
primary and secondary sludge. However these differences, both the
DTG and the DSC curves corresponding to the temperature programmed
combustion of their blends (sludge wt. 10%) were nearly
coincident with those corresponding to coal combustion. Moreover,
the apparent activation energy estimated for the co-combustion of
coal with primary or secondary pulp mill sludge approached that of
coal. On the whole, these results point to co-combustion of coal
with primary and, especially, with secondary pulp mill sludge as a
feasible management option for such wastes, which, furthermore,
may provide a reduction on CO2 and NOx derived emissions.