Abstract
Catalytic behaviour of iron-based catalysts on hydropyrolysis of nascent coal tar was studied using a two-stage fixed-bed reactor in ambient pressure. An Indonesian natural limonite ore was mainly employed as a representative iron catalyst at a temperature from 873K to 1023K and in 50 vol. % hydrogen atmosphere. The limonite catalyst exhibited a great activity on coal volatile methanation that methane concentration in carbonaceous gas product was achieved higher than 60% in volume and tarry material was converted almost completely. Comparing with two other iron-containing catalysts, Fe/Al_2O_3 and bof dust, limonite with a high specific surface area showed a high catalytic activity on tarry material hydropyrolysis. The influence of sulphur poisoning on the limonite catalyst was small. Carbonaceous gas products obtained in a 2000ppm H_2S atmosphere with limonite were still up to twice the total gas yield and twice methane yield (in moles) of those without catalyst at 923K.
