The Investigation on Fragmentation Behavior of Lignite Coal during Fluidized Bed Pyrolysis

Abstract

This paper reported the fragmentation behavior of lignite coal particles during coal pyrolysis in fluidized bed reactor at temperature of 300°C,350°C,600°C,650°C. The particles with size of 2-4mm,4-6mm and 7-10mm pyrolyzed under N2 atmosphere. The fragments were recovered by hopper, cooled to the ambient temperature and sieved in different ranks. Experimental results show that with the increasing of temperature and initial coal size due to internal overpressure induced by volatiles releasing and thermal stress caused by thermal gradient of coal intra-particles the intensity of fragmentation was enhanced monotonously, the number of fragments increased sharply and the average size of fragments declined.