A sludge pyrolysis system coupled with molten salt storage is an emerging novel thermal treatment technique for sludge disposal

which can simultaneously realize reduction and tar recovery by constructing rapid and homogeneous pyrolysis conditions. The effects of heating rate and calcium oxide(CaO) addition on the production characteristics of tar during sludge pyrolysis coupled with molten salt storage system were investigated via a high-precision optical wide heating rate pyrolysis apparatus. The results show that

the heating rate affected the tar yield at low pyrolysis temperatures. The tar yield increased by 14% at 350 ℃ when the heating rate increased from 60 ℃/min to 6 000 ℃/min. Meanwhile

the CaO addition could result in a sharp decrease in tar yield

an 39%～43% decrease could be observed with 10% CaO addition. Also

the CaO addition significantly affected the relative content of the compounds in tar

which was attributed to the fact that CaO could act as a catalyst and heat transfer retardant. The results are helpful to the pyrolysis condition regulation and high value-added tar obtain for the sludge pyrolysis system coupled with molten salt storage.