Microscopic studies on the dispersion of iron/molybdenum bimetallic catalysts in hydrotreated Blind Canyon, Wyodak and Pittsburgh #8 coals

The dispersion and reactivity of an iron/molybdenum coal liquefaction catalyst was investigated in three Argonne coals. Blind Canyon, Wyodak and Pittsburgh # 8 coal samples were impregnated with a 1 wt% Fe and 1 wt% Mo liquefaction catalyst using both ultrasonic and incipient wetness techniques. The yields of THF solubles in demineralized Blind Canyon coal indicate no significant advantage in the use of ultrasound as the impregnation technique. Results of electron probe microanalysis (EPMA) show that the catalyst is coated on the surface of impregnated, demineralized coal particles prior to hydropyrolysis at 350°C and 2000 psig H 2. EPMA micrographs obtained after hydropyrolysis indicate that the catalyst has entered the interior of demineralized coal particles. Mobility of iron and molybdenum evidently occurs during hydropyrolysis and possibly is facilitated by the liquid phase present in the demineralized coal and the amount of porosity. Corresponding EPMA data obtained from impregnated undemineralized coal samples are ambiguous.