1998 Volume 77 Issue 8 Pages 805-814
Three kinds of finely pulverized iron ores (limonite, pyrite and hematite) and four types of synthesized iron compound (α-FeOOH, γ-FeOOH, α-Fe2O3 and Fe3O4) were tested as precursors for direct coal liquefaction catalyst. The liquefaction activity was increased with a decrease in the average particle size of finely pulverized iron ore. The HS yield was higher in the order; γ-FeOOH> α-FeOOH, limonite > pyrite > hematite. The correlation of the catalytic activity between the liquefaction of Yallourn coal and the hydrogenation of 1-methylnaphthalene (1-MN) was examined, and it was found that HS yield closely related to the yield of demethylated products (tetralin + naphthalene). The activity for the C-C bond cleavage such as the demethylation activity should be required for iron catalyst in the liquefaction of coal. It appeared that the demethylation activity was correlated with the pore volume of spent catalyst which consisted of fine particles of pyrrhotite. TEM photographs indicated that the pyrrhotite formed from γ-FeOOH had the smallest particle size among the spent catalysts.