Coal gasification studies. Part III. Reduction in the presence of some metal iodides and iron halides

Abstract

Coal has been reduced at 600°C with H 2 (1700–3000 p.s.i.) in the presence of (1) iodides of the metals Fe, Cr, Mo, Ni, Sn and Zn, and (2) the halides of iron, Fe X 3 ( X = F, Cl, Br and I), as potential catalysts, CH 4, C 2H 4 and C 3H 8 were the only hydrocarbon reaction products. With the possible exception of ZnI 2, for which the results are somewhat equivocal, there is no reason to believe the iodides of these metals have significant catalytic effect on coal reduction. Rather, they act solely as a source of iodine which is the true catalytic agent. FeF 3 shows no catalytic activity in the reduction process, whereas the other iron halides apparently do, the order of effectiveness being FeI 3 > FeBr 3 > FeCl 3. Thermodynamic data are used to show that in part, at least, the effectiveness of these compounds as catalysts is probably associated with the equilibrium H X ⇌ H + X ( X = I, Br, Cl, and F) which produces a small finite steady state concentration of reactive H atoms in the system. The latter, in the HF system, is too low to have any significant effect on the reduction. The results of experiments on the reduction of some pure saturated aliphatic and aromatic compounds with H 2 O + Fe + I 2 are described.