Evaluation of Coal Chemical Structure

Abstract

Recent trends and future outlook of researches on chemical structure of coal have been reviewed, especially from aviewpoint of practical use of coal.
There are three major trends of researches : first, to show the average coal chemical structure ; second, to illustrate the coal structure ; and third, to consider coal as three-dimensional structure.
The future outlook of the researches has been discussed as follows : first of all, coal should be considered as organic materials that have molecular weight distribution secondly, it should be noted that coal has three-dimensional structure and that weak bridges which are not covalent bonds are important for thermal behavior of coals.