Measurement and simulation of flow properties of coal ash slag in coal gasification

• Published in: AIChE journal Vol. 57; no. 3; pp. 801 - 818
• Main Authors: Song, Wenjia, Sun, Yimin, Wu, Yongqiang, Zhu, Zibin, Koyama, Shuntarou
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.03.2011; Wiley; American Institute of Chemical Engineers
• Subjects: Applied sciences; Ashes; Chemical engineering; Coal; coal ash slag; Computer simulation; Crystallization; Exact sciences and technology; factsage; flow properties; gasification; Liquid phases; Liquids; Mathematical models; Measurement; Phase transitions; Simulation; Slag; Slags; Software; Temperature; Thermodynamics; Viscosity; Viscosity; coal ash slag; flow properties; Shear; Volume fraction; factsage; Software package; Solid particle; Liquid phase; Modeling; Coal gasification; gasification; Ash; Coal; Slag
• ISSN: 0001-1541; 1547-5905
• DOI: 10.1002/aic.12293

The viscosities of 45 coal ash slag samples at high temperature have been measured under different temperatures and shear rates. The computer thermodynamic software package FactSage has been used to predict liquidus temperatures, volume fractions of crystallized solid particles (ϕ), and the compositions of remaining liquid phase for 45 coal ash slag samples. The flow properties of completely liquid and partly crystallized coal ash slag samples have been predicted by three viscosity models. The Urbain formalism has been modified to describe the viscosities of fully liquid slag and homogeneous remaining liquid phase in coal ash slag samples. The modified Einstein equation and Einstein-Roscoe equation have been used to describe the viscosities of heterogeneous coal ash slag samples of ϕ < 10.00 vol % and ϕ ≥ 10.00 vol %, respectively. These three models provided a good description of the experimental data of fully liquid and heterogeneous coal ash slag samples. The new models also predicted flow properties of mixtures of coal ash slags with CaO, Fe₂O₃, MgO, SiO₂, and Al₂O₃. © 2010 American Institute of Chemical Engineers AIChE J, 2011