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3.4 Slurry Reactors 103

G

L

L

G
Figure 3.25 Slurry bubble column reactor (SBCR)

G
G

L

L

Figure 3.26 Agitated slurry reactor (ASR).

particles are kept suspended in the liquid by means of the gaseous reactants that enter the
reactor from the bottom, usually through a sparger in SBCRs, whereas in mechan- ASRs,
ical agitation is employed for retaining the suspension of the solids.
In general, much higher amounts of solids can be loaded in a bubble column than in an
v . agitated slurry reactorActual loadings of oer 30% (v/v) are kno whereas the respec- wn,
tive values for ASR rarely exceed 5% (v/v) (Stitt, 2002). In general, b ubble columns seem
more attractive than ASRs. Besides the high solid loadings that can be achieved, the oper-
xible,
v
ation of bubble columns is relatiely fle exhibiting good heat and mass transfer
v
behavior. Another advantage of bubble columns o ASRs is the ease of cleaning.
er
Although bubble columns are superior to ASRs in terms of performance, they hae more v
problems associated with scale-up (Stitt, 2002).
Slurry reactors could be of continuous type if the slurry (liquid and solids) flows through
the reactor or of batch type if the slurry is stationary in the reactor. In the following analy-
sis, we basically consider the batch type of slurry reactors (ASR and SBCR).