Coprocessing coal with hydrogenated vacuum pyrolyzed tire oil

GC-MS and NMR analyses of vacuum pyrolyzed tire oil (VPTO) show the presenc e of non-hydrogen donor polyaromatic molecules, such as naphthalene, anthra cene, phenanthrene, pyrene, and their methylated derivatives. Thus, VPTO pr ovides weak H-donor capacity. However, partial hydrogenations of VPTO conve rts the polyaromatics to hydropolyaromatic compounds, which are very good H -donor molecules. In this study, hydrogenation of VPTO was done using sever al types of presulfided hydrogenation catalysts, including Ni/Al2O3, CoMo/A l2O3, NiMo/Al2O3, NiW/Al2O3, Ni/SiO2-Al2O3, Pd/carbon, unsulfided Pt/Al2O3 and Pt/carbon. Hydrogenation of VPTO was also investigated at different tem peratures and hydrogenation pressures when the catalyst was Ni/Al2O3. The p artially hydrogenated VPTO (HVPTO) products were then coprocessed with diff erent coal ranks at several reaction temperatures and pressures with and wi thout finely dispersed Mo naphthenate, Mo(CO)(6), (NH4)(2)MoS4 and Mo/Fe2O3 /SO4 catalysts. The coprocessing of coal with several model compounds indic ated that solvent effectiveness varies in the order of (non-donor polyaroma tic model compounds)<(HVPTO)< (strong H-donor model compounds). No effect o f varying coal rank is observed. NiMo/Al2O3 (6.7% of NiO and 27% MoO3) and Ni/Al2O3 are the best catalysts for converting polyaromatics to hydrogen do nor-rich hydroaromatics among nine tested catalysts. The best hydrogenation conditions are 325 degrees C and 1000 psig of H-2 (cold). (NH4)(2)MoS4 and Mo/Fe2O3/SO4 are excellent coal liquefaction catalysts when HVPTO is copro cessed with coal. (C) 1999 Elsevier Science B.V. All rights reserved.