Composition of Polar Compounds in Coal-derived Distillable Liquids

Abstract

The qualitative and quantitative analysis of polar compounds in coal-derived distillable liquids has been carried out by GC and Fl-MS to investigate the effect of the origin of coals on the product composition. The coals used were those of Battle River, Yallourn, Wandoan, Taiheiyo, Illinois No.6, Horonai and Miike.
The hydroliquefaction was carried out at 450°C for an hour under the initial hydrogen pressure of 100kg/cm² using a presulfided hematite as catalyst and tetralin as solvent, and also lignin hydrocracking was carried out on the same conditions. Three polar fractions (acidic, basic and neutral polar fractions) were separated from the distillate (bp 150-430°C) in each coal-derived liquid (Fig.1).
The yields of the acidic, basic and neutral polar fractions were 4.1-6.3%, 0.9-1.6% and 3.5-5.6% (maf basis) respectively. The main components of the acidic fraction were monocyclic alkylphenols and bicyclic phenolic compounds such as naphthols, indanols and tetralinols. The composition of this fraction was similar for the seven above coals, and was also similar to that of the acidic fraction obtained from the lignin-derived distillable liquid (Table 5).
The basic fra ction was composed of bi-, tri- and tetracyclic aromatic compounds containing basic nitrogen (Fig.2), while the neutral polar fraction was composed of nonbasic nitrogencontaining compounds and phenolic compounds with many alkyl groups attached to the aromatic ring (Fig.3-A, 3-B).
In bituminous coal-deriv ed liquids, the contents of polyaromatic compounds in phenolic and nitrogen compounds were high as shown in Table 6.