Hm. Ettouney et al., HIGH-TEMPERATURE CO SHIFT CONVERSION (HTSC) USING CATALYTIC MEMBRANE REACTORS, Chemical engineering research & design, 74(A6), 1996, pp. 649-657
Models are developed for simulation of membrane reactors for the high
temperature shift conversion of carbon monoxide (GO). Three configurat
ions are considered in the analysis; the first employs a shell and tub
e arrangement, where the catalyst is placed inside the tubes which hav
e hydrogen-permeable walls. The second and third configurations make u
se of an existing HTSC system plus membrane separation cells for remov
al of hydrogen from the feed (second configuration) and from the feed
and effluent reaction mixture leaving the first catalyst bed in the re
actor (third configuration). For the first configuration, in situ reac
tion and separation of hydrogen takes place. Accordingly, a shift from
equilibrium occurs along the reactor length as a result of continuous
removal of hydrogen present in the feed and formed during reaction. O
n the other hand, a shift from equilibrium in the second and third con
figurations relies on the use of separate membrane cells for hydrogen
removal. CO conversions up to 0.99 are predicted in the first and thir
d configurations which implies that the CO content in the effluent is
below the maximum limit of 0.25 mole percent on a dry basis. Currently
, this limit is achieved by use of both high and low temperature shift
converters. This result suggests the possibility of the reconfigurati
on of a conventional CO shift conversion system, where it is feasible,
to eliminate the low temperature converter. Although both the first a
nd third configurations meet the desired limit on CO content in the ef
fluent, it is found that the amount of catalyst needed for the first c
onfiguration is much larger (more than five times) than that of the th
ird configuration.