Environmental Engineering Reference
In-Depth Information
Figure 9.1: Operational steps in the preparation of catalyst extrudates from spent catalyst [From
ref.
9
. Reprinted with permission].
was maintained at 500
◦
C. Under these conditions, most of the coke was removed. After
de-oiling and/or decoking, catalysts were ground to obtain particle size in the range of 25 to
90
m, which was similar as that of boehmite. Boehmite used in the study was a commercial
product manufactured by Sasol, Germany. It was in a powder form and had particle size in
the following range:
<
25
m (8%).
This solid was used for mixing with the ground spent catalysts to obtain a paste suitable for the
extrusion. The sequence of operational steps used for the preparation of extrudates from
spent catalyst-boehmite mixtures are shown in
Fig. 9.1 [9]
.
m (3%), 25 to 45
m (9%), 45 to 90
m (80%) and
>
90
The concentrations of Ni, Mo, and V in spent catalysts A, B, and C (
Table 9.1
)
[522]
and
laboratory prepared catalysts were determined using the inductively coupled plasma atomic
emission spectroscopy (Varian Liberty II ICP-AES). A mercury porosimeter (Quantachrome
