Research progress on co-firing coal with sewage sludge in circulating fluidized bed boilers
Reasonable disposal of sludge with high production and harmful substances in circulating fluidized bed boil-ers can improve the emission concentration of poollutants in the file gas to meet the standard,so the co-firing sludge in coal-fired circulating fluidized bed boilers has broad prospects.This article provides a comprehensive review of co-firing sludge in coal-fired circulating fluidized bed boilers from the aspects of sludge status,co-combustion mechanism,com-bustion conditions,existing problems,and optimization schemes.Co-firing coal and sludge can achieve complementary fuel characteristics and eliminate the negative characteristics of a single fuel.Combining domestic and foreign processes of co-firing sludge in coal-fired circulating fluidized bed boilers,it points out the effects of sludge co-firing on combus-tion efficiency,boiler internals,and pollutant emissions,and proposes specific measures to optimize combustion con-ditions.In conclusion,co-firing sludge in coal-fired circulating fluidized bed boilers can achieve sludge reduction,harmless treatment,and resource utilization.Pre-treatment of sludge,boiler systems,and numerical simulations need to be optimized and adjusted to ensure efficient and stable combustion of the mixed fuel in the furnace.