A method of predicting coal devolatilization behavior based on the elemental composition

An interpolation method was proposed to correlate the input parameters of a coal devolatization model[functional group-depolymerization, vaporization, cross-linking (FG-DVC)] to coals of a wide range of ranks, and it conceptually applicable to other devolatilization models. This method uses a set of well-defined coals (library coals) to form a triangular mesh in the van Krevelen diagram. If an unknown coal is within a triangle formed by three library coals, the model input parameters for this unknown coal can be interpolated from those of the three library coals based solely on the elemental composition. This method extends the FG—DVC model to be able to model any coal that can be interpolated, without the requirement for any additional characterization of the coal. It is also easy to accommodate more library coals so that a wider range of coal types can be covered. The validity of this method was demonstrated by comparing the tar yield measurements and the predictions for 27 coals over a wide range of pressures and heating rates. For most of the coals, the predictions compare very well with the data. For selected coals, data were available on the variation of the yield of total volatiles with pressure and heating rate, and again, good agreement was obtained. The model could be improved by using additional parameters to describe the exchangeable cation content, sulfur content, and/or the maceral composition.