With the ongoing investment in sewage treatment capacity in Flanders (Belgi
um), a new challenge is the management of the rising amount of sludge. Sinc
e sludge disposal to agriculture and landfill is regularly becoming Very di
fficult, alternative thermal disposal routes become more important. This pa
per presents the results of the various co-incineration tests with dried sl
udge in coal-fired power plants. The aim of this project was to investigate
whether adding dried sludge to the combustion process is technically possi
ble, whether the emissions remain below the permitted levels, and whether t
he quality of residual products remains acceptable. It is concluded that th
e co-incineration of dried sludge is a valuable and responsible sludge disp
osal option because it can be carried out in the existing units with a high
electrical efficiency. Also, sludge disposal is achieved with a limited in
fluence on emissions and residual ashes, without creating additional waste
streams. The main points of attention are a limitation of the cc-incinerati
on rate and the total input of sulphur, chloride and (earth) alkali element
s to avoid corrosion and fouling problems.