Capacity, packings

The moist cells were suspended in 750 parts of volume of ethanol and extracted by warming at 60°C for 1 hour. A total of 3 extractions were carried out in a similar manner and the extracts were pooled, diluted with water and further extracted three times with 1,000 parts of volume portions of n-hexane. The n-hexane layer was concentrated to dryness under reduced pressure to recover 4.12 parts of a yellow oil. This oily residue was dissolved in 6 parts by volume of benzene and passed through a column (500 parts by volume capacity) packed with Floridil (100 to 200 meshes). Elution was carried out using benzene and the eluate was collected in 10 parts by volume fractions. Each fraction was analyzed by thin-layer chromatography and color reaction and the fractions rich in ubiquinone-10 were pooled and concentrated under reduced pressure. By this procedure was obtained 0.562 part of a yellow oil. This product was dissolved in 5 parts by volume of chloroform, coated onto a thin layer plate of silica gel GF254 (silica gel with calcium sulfate) and developed with benzene. The fractions corresponding to ubiquinone-10 were extracted, whereby 0.054 part of a yellow oil was obtained. This oil was dissolved in 10 parts by volume of ethanol and allowed to cool, whereupon 0.029 part of yellow crystals of ubiquinone-10 were obtained, its melting point 4B°to 50°C. 

Figure 9-6M. Metal VSP high capacity packing. Used by permission of Vereinigte Fulikorper-Fabriken GmBH Co. Ransbach Baumbach, Germany.

Aquamatrix (96-well plate with 1- or 2-mL capacity packed with calcined diatomaceous earth)... 

Fig. 7.11. Cost contributions at two column saturation capacities packing, solvent, lost crude, labor and system, (a) 1000 mg/g, and (b) 500 mg/g. Absolute cost /g, cost component, % fractional cost.

The use of packing instead of trays in multistage separation columns is common for column diameters 3-4 ft or smaller. More recently, packing has been used for larger columns because of its low pressure drops, favorable efficiencies, and high vapor capacity. Packed columns are also the preferred choice where corrosion is a potential problem. The packing material used in these situations is ceramic or polymeric. Another characteristic of packed columns is their low liquid holdup, which could reduce the amounts of off-specification products at startup and shutdown. 

Table I. Calculated Flooding Points for High Capacity Packings...

Table I lists calculated flooding mass velocities for Munters and other high capacity packings. Munters packing can tolerate a wider range of conditions without flooding. Table II lists the mass transfer coefficients obtained in the experimental work with Munters packing (6).

Alix, R, and Raynal, L. (2008), Liquid distribution and liquid hold-up in modern high capacity packings, Chemical Engineering Research Design, 86(6) 585-591. 

Figure 16.5 Photograph of a Montz high-capacity packing B1-250 M and schematic design illustration [8]. (Permission provided by Julius Montz GmbH.)...

Large-bore capillaries (i.e., 530-p.m capillaries have narrowed the advantage of high-capacity packed columns also, the availability of more sensitive detectors has reduced the requirement for large samples)... 

The lower sections of water quench towers typically employ baffle trays, splash decks, or angle trays. These devices have a very low efficiency, so that 6 to 12 actual trays are installed, which develop a pressure drop of only 0.02 psi per actual tray. If the effluent liquid from this lower section of the tower could be heated an additional 5°F, the useful heat available for cold section reboilers would increase from 77% to 82% of the total heat load on the water quench column. When this section is equipped with high capacity packing, the exit liquid temperature can be raised to within about 5°F of the inlet vapor adiabatic saturation temperature. This can be done without increasing the pressure drop compared to the trays. Normally a 10-ft to 14-ft depth of 70IMTP pacldng is specified for the lower section. Such a packed depth provides a 70% to 100% increase in theoretical stages compared to the trays that are replaced. 

Fig. 120. Photograph of a segment of J. Montz s high capacity packing Bl-250 M.

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