Structure and Reactivity of Residual Carbon from Circulating Fluidized Bed Coal Gasification Fine Ash

Due to the high carbon and ash content of coal gasification fine ash (CGFA) produced by circulating fluidised bed gasifiers (CFBG), it is mainly dissipated in landfills and energy wastage. Large-scale dissipation of CGFA can be achieved if the carbon in CGFA has active oxidation properties and potential as a material for the preparation of carbon. Demineralisation of different types of CGFA from a CFBG with a gas production capacity of 40,000 Nm3/h was carried out to obtain demineralised carbon (DC) and to investigate the structure and reactivity of the DC. The aromatic carbon and aliphatic hydrocarbon functional groups of DC rose, and the oxygen-containing functional groups all had different degrees of decreasing trends. The chemical structure model of CGFA was constructed based on the changes of CGFA chemical structure by deashing treatment. Through TG experiments and Raman analysis of the samples, the activation energy value of DC was less than 70 kJ/mol, and the relationship between carbon structure and combustion reactivity by Raman characterization was constructed. the specific surface area of DC was above 350 m2/g, and the activated carbon was prepared by KOH and high temperature activation, and the specific surface area of activated carbon reached 1636.2211 m2/g with a pore volume of 1.6796 cm3/g and a density of 1 g/cm3. CGFA has the potential to be used as a fuel and DC can be used as an adsorbent or a precursor for pressed activated carbon