Abstract
100 samples of recycle solvent were obtained from continuous opera-tion (50 days) of 1 ton/day coal liquefaction plant at Kimitsu. Pyrene and fluoranthene derivatives in the recycle solvents were anslyzed in detail by the technique of selective ion measurement of GC/MS. According to the replacement of the initial solvent by coal-liquid solvent, the sum yields of pyrene and fluoranthene derivatives decreased: the yields of pyrene derivatives and fluoranthene derivatives in the recycle solvents after 50 days operation was ca. 1/2 and 1/10 of those in the initial solvent, respectively.
Principal reactions of pyrene, methylpyrenes, and fluoranthene in the solvent hydro-genation process were hydrogenation to hexahydropyrenes, to dihydromethylpyrenes, and to tetrahydro-and decahydrofluoranthenes, respectively. In order to controle the hydrogenation of recycle solvent during hydrotreating step, the relative amount of pyrene and hexahydropyrene in the recycle solvent was considered to be a suitable indi-cator.
