Abstract: At present, the deacidification process of flue gas of established sludge incineration projects in China mostly adopts the wet process-based route. For the projects constructing in the “isolated island” mode, the cost of zero discharge of deacidification wastewater is high, while the operation cost of the wet-based deacidification route has no advantages. The deacidification process of an “isolated island” sludge incineration project was taken as the research object, the characteristics of the commonly used deacidification process were analyzed. Meanwhile, seven schemes were set up from the aspects of deacidification agent selection, deacidification efficiency allocation, fly ash chelation and so on, in order to contrast the operating cost of different process combination schemes, and demonstrate the rationality of the selection of deacidification process route for this project. Finally, suggestions on the selection of flue gas deacidification process for sludge incineration projects were put forward combined with the feasibility of wastewater discharge and fly ash chelation, which could provide reference suggestions for the design of new sludge incineration or process transformation projects.

Key words: sludge incineration, combinatorial deacidification, operation cost, boundary conditions, fly ash chelation and curing