A study on the chemical state of carbon present in fine ash from gasification

Abstract Taking feed coal as a reference, the chemical states, content changes, microstructure, distribution, and graphitizable extent of carbon present in gasification fine ash were investigated in detail. The results show that the fine ash includes a significant amount of unreacted carbon. The C1s spectrum is composed of four components in which the contents of C–C and C–H decrease dramatically and graphitized carbon (39.1%) presents. The elemental carbon primarily distributes on the layer structure, whereas elemental silicon and aluminum are mainly found on spherical particles embedded in the layer structure. After gasification, carbon atoms in gasification fine ash are arranged in an orderly manner, and the extent of graphitization of carbon increases, which indicates that carbon in feed coal may be partly graphitized and deposited in fine ash during gasification process.