Thermogravimetric and rock-eval studies of coal properties and coal rank

A wide range of coal ranks from lignite to anthracite has been investigated using thermogravimetric analysis (TGA). The derivative peak maximum for vo latile matter evolution shows a strong correlation (r(2) = 0.998) with vitr inite reflectance, thereby providing a convenient measure of degree of coal ification (coal rank) without requiring the equipment of and more time-cons uming petrographic analysis. T-max by the Rock-Eval method also shows a pos itive although somewhat poorer correlation (r(2) = 0.856) with vitrinite re flectance. TGA also reproduces the components of the proximate analysis of coal.