1996 Volume 75 Issue 2 Pages 93-98
Single ion chromatograms obtained by GC/MS were used for the evaluation of qualities of recycle solvents obtained from a lton/day coal liquefaction plant.
The compositional changes of n-paraffins, major aromatic compounds and C0-C4-phenanthrenes during the 50 days' operation were clarified. The content of n-paraffins (C14-C30) in a recycle solvent increased gradually from 6.6% to 15.9%. The aromatic compounds which increased relatively after 50 days were two and three cyclic compounds such as naphthalenes and acenaphthenes, and compounds containing five-menbered and dihydrophenalene-type naphthenic rings and pyrene ring. Phenan-threne and methylphenanthrenes decreased significantly, but the contents of C2-C4-phenanthrenes had minor changes.
C2-C4-Naphthalenes, phenanthrene and their hydrogenated homologues could be determined easily by using GC/MS chromatograms for the recycle solvents, and both the ratios of tetralins/ (naphthalenes+tetralins decalins) and (2H+4H+8H) / (0H+2H+4H+811+14H)-phenanthrenes were shown to be a good parameter for hydrogen donor ability of a liquefaction recycle solvent when the composition of the recycle solvent did not change remarkablly.