CHEMICAL AND THERMOCHEMICAL PROPERTIES OF HEAVY MOLECULAR-WEIGHT HYDROCARBONS EVOLVED DURING RAPID HEATING OF COAL OF VARYING RANK CHARACTERISTICS

The evolution phenomenology, yields, chemical, and thermochemical prop erties of heavy hydrocarbons, tars, evolved from a wide range of coal types are presented. Coals varying in rank characteristics from lignit e to anthracite were rapidly heated to varying extents of devolatiliza tion, the tars isolated from the char stream and subjected to chemical and thermochemical analysis. Systematic variations in the yields, che mical characteristics, thermophysical and thermochemical properties ar e observed for a given extent of tar evolution from coals of varying r ank. Systematic variations are also observed for a given extent of tar evolution from coals of varying rank. Systematic variations are also observed for a given coal but with changing extents of devolatilizatio n. Despite significant variation in the molecular types, yields and te mperature-sensitivity of heavy hydrocarbons with coal type, underlying invariances are observed in the evolution sequence of parent coal nit rogen, volatility, functional group distributions, and calorific value s of evolved tar species as a function of extent of tar evolution.