Circulating fluidized bed(CFB) boiler has wide adaptability of fuels and can realize desulphurization in furnace

which is considered as one of the best boiler types for industrial co-combustion application of coal and sludge. From the aspects of co-combustion conditions

pollutant emission and control

and numerical simulation

the co-combustion of coal and sludge in CFB boilers is reviewed in this paper. The existing researches and industrial applications show that

the mechanical dewatered sludge being dried by the waste heat of flue gas or the low-grade steam of furnace could be mixed with coal

biomass and garbage for combustion

which was considered as the recommended method for co-combustion of sludge. For different types and sources of sludge

the sludge blending ratio could not be larger than 30%. The optimum bed temperature of furnace could be controlled at about 900 ℃

which would be beneficial for slowing down the high temperature slagging of CFB boiler. In general

the influence of co-combustion of sludge on SO_2 and NO_x emissions was limit. For the dioxin problem in the process of cocombustion of sludge

the control measures could be taken from the perspectives of fuel source

combustion and post-combustion. The emission of heavy metals from flue gas increased significantly with the mixed ratio of sludge

so the fly ash should not be reused only after further disposal. In brief

the co-combustion of coal and sludge in CFB boilers can not only recover the sludge energy

but also reduce the sludge quantification to the maximum extent

which has broad development and application prospects. The pollutants' emission standard can be satisfied with the existing pollutant removal equipments. Nonetheless

the relevant overall numerical models of CFB boilers have not appeared and should be improved in the future.