Energy & Fuels 2000, 14, 227-233
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Experimental Options for Determining the Temperature for the Onset of Sintering of Coal Ash A. Y. Al-Otoom,*,† G. W. Bryant,† L. K. Elliott,† B. J. Skrifvars,‡ M. Hupa,‡ and T. F. Wall† Cooperative Research Centre for Black Coal Utilisation, Department of Chemical Engineering, University of Newcastle, Callaghan, NSW2308, Australia, and Department of Chemical Engineering, Åbo Akademi University, Turku, Finland Received September 9, 1999. Revised Manuscript Received October 30, 1999
This paper presents a comparison of techniques that can be used to obtain the sintering temperature of coal ash. These techniques are thermal conductivity analysis (TCA), thermomechanical analysis (TMA), the compressive strength test (CS), and a proposed new technique called the pressure-drop technique. Generally, the results from these four techniques compare well and showed sintering temperatures in the range of 600-1000 °C. These temperatures reflect the onset of strength development in coal ash deposits. An analysis of the results indicates the compressive strength and thermal conductivity techniques are believed to overestimate the sintering temperature of coal ash as measurements were conducted at temperature intervals and these measurements depend on the treatment time. Thermomechanical analysis and pressuredrop techniques are believed to provide a more accurate indication of the sintering temperature due to the constant monitoring of ash structural changes and the inherent sensitivity of the methods to structural changes.
Introduction The present work forms a part of an ongoing project based on ash issues in pressurized fluidized bed combustion (PFBC). PFBC is a relatively new process for generating electricity via fluidization and combustion of coal at relatively high pressures (10-20 atm) and low temperatures (
