Investigation of the rank dependence of tar evolution. Final report

The objectives of this investigation are to develop an improved understanding of the process of coal tar evolution, its relationship to the structural characteristics of the parent coal, and the dependence of the chemical and physical properties of the tar products on the conditions of devolatilization. Characterization of the parent coal samples includes data on elemental composition, high temperature ash, moisture content, calorific values, and FT-IR spectral data. Characterization of the properties of the products of devolatilization includes data on the elemental composition and calorific values of tars and chars, molecular weights of tars, and light gas yields. The devolatilization behavior of coals ranging in rank from a Texas lignite to a Pennsylvania anthracite have been examined to gain insight into the influence that changes in parent coal structure can exert upon tar evolution phenomenology. (VC)