Chemical Structure of Pyridine Soluble Matter of Coal Liquefaction Residue

Abstract

Although NEDOL process is one of the highest yield processes of coal liquefaction, part of coal remain as a coal liquefaction residue. A usage of the coal liquefaction residue needs to be developed for the establishment of NEDOL process. The studies on the characterization of the coal liquefaction residue began by using various measurements. In this paper, solid-state ¹³C-NMR spectroscopy has been applied to structural characterization of the pyridine soluble matter of the coal liquefaction residue.
The analysis of carbon functional groups was performed by curve-fitting techniques of the conventional CP/MAS spectrum. The apparent ratio of quaternary to tertiary aromatic carbons was determined with dipolar dephasing experiments on the sample. Using this ratio and the distributions of carbon functional groups, several parameters can be obtained on its average chemical structure. Pyridine soluble matter of the coal liquefaction residue was evaluated to consist of four to five aromatic rings with a few methyl and hydroxyl groups and naphthene rings.