Db. Bukur et al., ACTIVATION STUDIES WITH AN IRON FISCHER-TROPSCH CATALYST IN FIXED-BEDAND STIRRED-TANK SLURRY REACTORS, Canadian journal of chemical engineering, 74(3), 1996, pp. 399-404
A precipitated iron catalyst (100 Fe/5 Cu/4.2 K/25 SiO2 on a mass basi
s) was tested in a fixed bed reactor and a stirred tank slurry reactor
under the same process conditions (250 degrees C, 1.48 MPa, 2 L(STP)/
gcat . h, H-2:CO=2:3). Two different pretreatment procedures were empl
oyed (hydrogen reduction at 220 degrees C and carbon monoxide activati
on at 280 degrees C) in each of the two reactor types. In the stirred
tank slurry reactor tests the activity (based on an apparent first ord
er reaction rate constant) of the carbon monoxide pretreated catalyst
was about 25% higher than that of hydrogen reduced catalyst, due to in
complete reduction of the latter. In all tests the catalyst selectivit
y changed slowly with time on stream. Hydrocarbon distribution shifted
toward lower molar mass products, and secondary reactions (l-olefin h
ydrogenation, isomerization and readsorption) increased with time. The
secondary reactions were the most pronounced on the hydrogen reduced
catalyst in the fixed bed reactor.