Comparison of Natural and Synthetic Petroleum Coke Slag Viscosities under Reducing Conditions: Applicability of Predictive Models Using Factsage and Modified Urbain Model

Abstract

The viscosity of slag from an operating integrated gasification combined cycle (IGCC) plant utilising petroleum coke and a synthetic petcoke slag with the same composition made from chemical grade oxides in a reducing environment for gasification application were investigated in this study. A high temperature rotating bob-type viscometer was used to measure viscosity between temperatures of 1250–1375 °C. Natural and synthetic ash had similar viscosities above 1300 °C in this study. The viscosity was predicted by using FactSage, a thermodynamic modelling software, in conjunction with different viscosity models, available in the open literature. Percentage deviations of predicted viscosities from different models with experimentally measured values ranged from about 41 to 151%. Crystallisation of the slag was noted in SEM-EDS (scanning electron microscopy– energy dispersive spectroscopy) and FactSage results. Solid phases from FactSage predictions were used to modify the Kalmanovitch–Frank model with the Roscoe method. It predicted the viscosity of the slag accurately between 1250 and 1375 °C. Average percentage deviation from measured natural ash viscosity was about 11%.

Application of Liquidus Projections in SiO2–Al2O3–CaO Systems with Fe2O3 and V2O5 to Study the Dissolution of Alumina Crucibles in Gasification Slags Containing Vanadium

“…Saturation solubility was quite high (58.36 wt %). This can explain the crucible condition 59 in Figure 10 —the slag penetrated almost the entire width (∼2.6 mm) of the crucible in some regions. Here, V_spinel (solid solution) was the primary phase, with hercynite as the major component (54.8 wt %) at 1400 and 1500 °C.…”

“…In tests 3–5, viscosity measurement experiments were performed in the in-house high-temperature viscometer. − Test 3 used petcoke ash obtained from a gasification plant. Saturation solubility was quite high (58.36 wt %).…”

“…Crucibles after completion of tests 1a* and 1b* were found to be perforated. In our previous studies, tests 2a, 8 2b* (ash composition same as 2b), 8 2c* (ash composition same as 2c), 8 3, 43 4, 44 and 5 45 were performed to measure slag viscosities in alumina crucibles in an in-house high-temperature viscometer. The atmospheres used and the maximum temperatures attained during the experiments are listed in Table 1 .…”

Towards a Mechanistic Understanding of the Slagging Propensities of Petroleum Coke: Lessons Learned from Its Co-Combustion with Natural Gas in Oxygen-Enriched Atmospheres

“…While pulverized fuel PC combustion systems are the focus of this study, the insights and implications may yield valuable insights into other PC combustion scenarios as well. For instance, the challenges in estimating µ P of PC fly ash (albeit at temperatures higher than those investigated in this study) were highlighted recently by D'Souza et al [27],…”