β Scribed by H.P. Tseng; T.F. Edgar
No coin nor oath required. For personal study only.
A bifurcated cylindrical pore model has been developed to simulate the change of the physical properties of coal char during gasification or combustion. This model demonstrates that changes in the pore structure of coal char can be characterized by dividing the pores into micropores and macropores. Because the micropores provide most of the char surface area, the change in the surface area can be simulated by using a single size micropore model. The evolution of surface areas predicted by the bifurcated pore model agrees well with the experimental data. The model further illustrates that under kinetic control, the combustion characteristic curve is a function of the initial micropore porosity. For char with very small initial micropore porosity, a single (master) curve can characterize the combustion behaviour of coal char.
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Anthracite char is used in an industrial process as reducing agent at temperatures above 750Β°C for the reduction of sulphur dioxide in SO,-rich gases produced by regenerative processes for flue gas desulphurization. The reactions of sulphur dioxide and water vapor, if water vapor is present, do not
Intrinsic oxidation rates of coal chars derived from three different bituminous coals were measured at 5WC and the effects of char formation temperature, conversion, coal particle size and char particle size on the rates were evaluated. Characterization of the various samples including BET surface a
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