Distillation packing

Figure 9.3 Distillation packing. (From Smith R and Jobson M, 2000 Distillation, Encyclopedia of Separation Science, Academic Press reproduced by permission).

Sundmacher K, Hoffmann U. Activity evaluation of a catalytic distillation packing for MTBE production. Chem Eng Technol 1993 16 279-289. 

Moritz P, Hasse H. Fluid dynamics in reactive distillation packing Katapak-S. Chem Eng Sci 1999 54 1367-1374. 

However, the mass transfer coefficients found are clearly lower than those reported for distillation packings [26, 27]. This can be explained by the flow patterns in distillation packings, where the films constantly are disturbed and remixed, and therefore a completely developed laminar profile is never present. The mass transport is dominated by convection, not diffusion. It would be expected that remixing of the film layers, as accomplished by the stacking of monoliths (see Section 8.23) improves not only the RTD but also the mass transfer performance of monoliths. 

In this section, only general findings will be discussed which are valid for all packings investigated. Differences between the monolith types or between distillation packings and monoliths, which can be explained by the different flow patterns, are discussed in Section 8.4. 

In this section, the effects on reactor performance caused by different flow patterns or geometries of the packings investigated are discussed. The first section examines the influence of different monolith channel geometries, whilst in the second section monoliths and distillation packings are compared. 

Olujic, Z., Kamerbeek, A.B., Graauw, J. A corrugation geometry based model for efficiency of structured distillation packing. Chem. Eng. Process., Vol. 38,683-695, 1999. 

Operating experience with the sandwich structure in trickle-bed mode is as yet limited, but its behavior is sufficiently similar to that when employed as a catalytic distillation packing, in terms of liquid holdup/residence time, mass transfer, and pressure drop, to allow design of pilot plant for these parameters to be made with confidence. 

Finally, the same care must be taken as with nonreactive distillation packings in ensuring that the gap between the structure and the column wall is sufficient to prevent flow of liquid onto the wall (on which it will then remain) while not so large as to promote gas bypass. This compromise is usually achieved with the aid of annular collars fitted to the structure itself. 

Production of catalyst materials in the shape of distillation packing is also expensive. 

K. Sundmacher, U. Hoffmann, Activity Evaluation of a Catalytic Distillation Packing for MTBE Production, Chem. Eng. TechnoL, 1993,16, 279-289. 

Zhang G, Cussler EL. Hollow fibers as structured distillation packing. J Membr Sci 2003 215(1—2) 185-93. 

Our solution is the combination of the properties of the catalytic polymer and a mechanical strong Inorganic support in the form of a distillation packing. 

---