Reactive Packings

The design of the reactive packings was developed by assessing the packing characteristics of several configurations in the same rig that was used to test the non-reactive packings. Flooding was experienced in the packed column apparatus for all materials and catalyst loadings using the sachet design (Chapter 11, Figure 11.2a) with a liquid flow of 2.5 L/min and a vapour flow of 120 L/min. The catalyst bale design (Figure 11.2b) provided sufficient capacity to prevent flooding at moderate to high air and water flows. The measured data are indicated in Table 12.2 with calculated dimensionless parameters for the Eckert generalised pressure drop correlation (GPDC) (Kister, 1992). The generalised parameters permit the packing factor to be estimated for both types of reactive packings (Table 12.2).

Table 12.2 - Hydraulic Capacity of Catalyst Bales (Air-Water Tests)

Air

Water

AP

Flow

Capacity

Packing

Configuration

(L/min)

(L/min)

(mm HzO)

Parameter

Parameter

Factor

Basic catalyst

200

2.5

12

0.36

0.035

1860

bale

300

3.5

47

0.34

0.058

1370

Catalyst bale

200

2.5

7

0.36

0.030

1590

with mesh

300

3.5

22

0.34

0.045

1060

interleave

The capacity parameter and flooding point can be estimated for the expected operating conditions using the estimated packing factors determined with the air-water tests. This data is shown in Table 12.3 and indicates that both the basic catalyst bale or the catalyst bale with mesh interleave have sufficient hydraulic capacity. Although the capacity parameter is equal to the flooding point for the basic catalyst bale (i.e. 100% flooding factor), the high pressure drop that was observed with the air-water tests without the onset of flooding generate confidence that flooding will not be experienced in the pilot plant column. Although the use of the catalyst bale with mesh interleave would provide greater certainty that flooding will be avoided, the basic catalyst bale design was preferred since it was considered to provide a larger liquid contact surface which should promote the reaction.

Table 12.3 - Expected Operating Conditions tor the Catalyst Bales

Flow

Capacity

Flood

Acceptable?

Configuration

Parameter

Parameter

Point

Basic catalyst bale

0.13

0.12

0.12

y

Catalyst bale with mesh

0.13

0.10

0.12

interleave

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