Chemical Structure of Coal-derived Liquids

Distillation Characteristics of Compound Classes by Simulated Distillation GC

Abstract

Akabira coal-derived neutral oil, free of the acidic and the basic portions, was separated according to boiling range into 25 fractions with 4°C-25°C interval using spinning band distillation. These fractions were separated into 6 compound classes, which were Fr-P (paraffin), Fr-M (monoaromatic), Fr-D1 (naphthalene type diaromatic), Fr-D2 (biphenyl type diaromatic), Fr-T (tri and/or tetraaromatic) and Fr-PP (polar and/or polyaromatic), using HPLC equipped with Zorbax BP-NH₂ column.
Using simulated distillation gas chromatographic technique (SD-GC), the boiling point of each distillation-HPLC fraction was determined. The result showed that the apparent boiling point estimated by SD-GC for each compound class having the same distillation fraction had the highest value for paraffin series and decreased gradually with increase in aromatic ring number from Fr-M to Fr-T, although the difference in the boiling point between SD-GC method and the fractional distillation method was not so large (less than nr) for each fraction.
The distribution of each compound class by boiling point was determined by SD-GC of all the neutral oil-HPLC fractions. Fr-P was widely distributed in each boiling range from 183°C to 423°C, and the boiling ranges of the aromatic fractions (Fr-M, Fr-D1, Fr-D2 and Fr-T) were shifted to higher boiling point with increasing aromatic ring number in this order.