Application of FactSage® thermodynamic modeling for predicting the ash transformation with temperatures under partial slagging entrained flow coal gasification condition

Ash fusion temperature determines suitability of coal for the entrained flow gasification/combustion process. For this, an Indonesian "Sehwa" coal sample and its acidic ash and slag constituents have been comprehensibly characterized via X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and inductively coupled plasma optical emission spectrometry (ICP-OES) methods. For assessment of environmental impact, leachate solution was also prepared from the discharged slag for ICP-OES analysis. The experimental data were comprehensively explained by ash fusion temperature and FactSage (R) thermochemical software and databases for understanding the thermodynamic fluidity properties of the coal ashes. More specifically, coal slagging behavior inside of the coal gasifier/combustor necessitated optimization of operational condition for subsequent mild slagging. The currently used coal gasification operation temperature range caused insufficient fraction of liquid available at 1200 to 1300 degrees C (19.7-20.1 bar). The metallic element-wise compositional analysis result via ICP-OES performed on the leachate solution therefrom excluded possibility of secondary environmental pollution from the discharged slag. This contribution continues the already published studies of the physicochemical characterization of slag waste from coal gasification syngas plants supplemented with FactSage (R) thermodynamic modeling results of coal gasification slag (SiO2-Al2O3-TiO2-Fe2O3-CaO-MgO-Na2O-K2O-P2O5-MnO-SO3). Besides, essentially similar experimental procedure to that employed in the already published studies was used to compare ash transformation and slagging behavior of the acidic coal feedstock.