Experimental study on high-temperature gasification and melting characteristics of the pyrolysis residue from petrochemical sludge

Abstract High-temperature gasification and melting is a promising technology for the harmless disposal and resource utilization of hazardous organic solid wastes. In this study, the high-temperature gasification and melting properties of pyrolysis residues from petrochemical sludge (PRPS) were experimentally investigated. Firstly, the PRPSs in pyrolysis temperatures of 500–700 °C were prepared. The gasification reactivity of PRPSs was investigated through micropolitics pore structure and Raman spectrum analysis. The results show that the PRPS prepared at 650 °C has the best gasification reactivity, with both large surface area and more complete porous structure, and more disordered carbon microstructures. Then, based on the PRPS sample prepared at 650 °C, the effects of the gasification temperature (1100–1400 °C) and atmosphere (N2, H2O, and CO2) were studied. In the atmosphere of 40 vol.%N2/30 vol.%CO2/30 vol.%H2O, the yield of effective gas (CO+H2) began to decrease when the temperature was above 1200 °C. With the increase of temperature (1300–1400 °C), high-density slag of PRPS was observed. At the temperature of 1400 °C, the highest yield of effective gas (CO+H2), the high-density slag, and the reduction of PRPS were obtained in the atmosphere of 40 vol.%N2/60 vol.%CO2. In this condition, the high CO is conducive to form FeO as fluxing. Moreover, the stable mineral phases (CaSiO3, CaSi2O7, etc.) were detected, which should perform a good solidification effect of heavy metals in the slag.