Bongjin Jung

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

Abstract 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® 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 °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® 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.

Physico-chemical characterization of slag waste from coal gasification syngas plants: Effect of the gasification temperature on slag waste as construction material

Abstract The ash fusion temperature determines the suitability of coal for the entrained flow gasification/combustion process. For this purpose, Indonesian KPU coal samples and their ash and slag contents were 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. To assess their environmental impacts, leachate solutions were prepared from the discharged slag for ICP-OES analyses. The experimental data were comprehensively explained in terms of ash fusion temperatures and fluidity properties of the coal ashes. More specifically, the coal slagging behavior inside of coal gasifier/combustors necessitated optimization of the operational conditions for subsequent mild slagging. The currently used coal gasification operation temperature ranges favored mild slagging at 1200 to 1300 °C (19.9 to 20.1 bar) and incomplete slagging at 1100 to 1200 °C (19.7 to 20.4 bar), which was attributed to the insufficient gasification/combustion temperature for the coal samples under the latter gasification/combustion conditions. The metallic elemental composition analysis results via ICP-OES performed on the leachate solution therefrom excluded the possibility of secondary environmental pollution from the discharged slag.