Bulk hquid

Chiral additives, however, do pose some unique problems. Many chiral agents are expensive or are not commercially available, and therefore, must be synthesized. The presence of the chiral additive in the bulk Hquid phase may also interfere with detection or recovery of the analytes. Finally, the presence of enantiomeric impurity in the chiral additive may add analytical complications (10). 

Mass transfer rates may also be expressed in terms of an overall gas-phase driving force by defining a hypothetical equiHbrium mole fractionjy as the concentration which would be in equiHbrium with the bulk Hquid concentration = rax ) ... 

Storage. Phenol is shipped in dmms, tank tmcks, and tank cars. It is loaded and shipped at elevated temperatures as a bulk Hquid. In storage, phenol may acquire a yeUow, pink, or brown discoloration which makes it unusable for some purposes. The discoloration is promoted by the action of water, light, air, and catalysts, eg, traces of iron or copper. When stored as a solid in the original dmm or in nickel, glass-lined, or tanks lined with baked phenolic resin, phenol remains colorless for a number of weeks. 

Determination of the Gas-Phase Temperature. The development given above is in terms of interface conditions, bulk Hquid temperature, and bulk gas enthalpy. Often the temperature of the vapor phase is important to the designer, either as one of the variables specified or as an important indicator of fogging conditions in the column. Such a condition would occur if the gas temperature equaled the saturation temperature, that is, the interface temperature. When fogging does occur, the column can no longer be expected to operate according to the relations presented herein but is basically out of control. 

The transformation of bulk Hquid to sprays can be achieved in many different ways. Basic techniques iaclude applying hydraulic pressure, electrical, acoustic, or mechanical energy to overcome the cohesive forces within the Hquid. 

States or Australia. In some cases, pot stills, arranged in cascade, are still used. The more sophisticated plants employ one or more carbon steel or cast-iron vessels heated electrically and equipped with temperature controls for both the bulk Hquid and the vessel walls. Contact time is usually 6—10 h. However, modem pitches are vacuum-distilled, producing no secondary quinoline insolubles, to improve the rheological properties. 

Ready availabiHty and easy appHcation of bulk Hquid carbon dioxide have caused it to replace dry ice in many cases. Liquid CO2 can be stored without loss and is easily measured or weighed. Liquid carbon dioxide is also used, along with dry ice, for direct injection into chemical reaction systems to control temperature. 

At this stage of manufacture, chocolate may be stored for future use in bulk Hquid form if usage is expected to be within one to two weeks, or at 43—50°C in a hot water jacketed agitated tank or in soHd block form where it can be stored for as long as 6 to 12 months. Blocks typically weigh between 3 and 30 kg. Storage conditions for block chocolate should be cool and dry, ie, 7 to 18°C and 40 to 45% relative humidity. If chocolate has been stored in block form, it can be remelted to temperatures up to 50°C and then processed in the same manner as freshly made Hquid chocolate. 

If it is desired to calculate the rate of transfer from the overall concentration difference based on bulk-hquid compositions (x° — x), the appropriate overall coefficient Kl is related to the individual coefficients by the equation... 

Region III, P < 0.02. Reaction is slow and occurs in the bulk hquid. Interfacial area and liquid holdup should be high, especially the latter. Bubble columns will be suitable. 

Equations 9.2-28 and -29, in general, are coupled through equation 9.2-30, and analytical solutions may not exist (numerical solution may be required). The equations can be uncoupled only if the reaction is first-order or pseudo-first-order with respect to A, and exact analytical solutions are possible for reaction occurring in bulk hquid and liquid fdm together and in the liquid film only. For second-order kinetics with reaction occurring only in the liquid film, an approximate analytical solution is available. We develop these three cases in the rest of this section. 

PolycrystalHne membrane growth proceeds by initial formation of a gel layer on the surface of the support crystallization takes place at the interface between the bulk Hquid phase and the gel layer, resulting in deposition of zeolite nuclei and crystals formed [8]. Concurrently, the crystals deposited onto the support surface continue to grow, eventually resulting in a continuous membrane layer. Postsynthesis treatment is necessary when a template is used in synthesis to activate the zeolite and open the pores. Usually this is accomplished through calcination or burn out of the organic molecule. 

Initial concentration of the carrier is the same as in a bulk hquid membrane phase. 

Schlosser S, Rothova I, and Frianova H. Hollow-fiber pertractor with bulk hquid membrane. J Mem Sci, 1993 80 99-106. 

Leon G and Guzman MA. Facilitated transport of cobalt through bulk hquid membranes containing diethyUiexyl phosphoric acid. Desalination, 2004 162 211-215. 

Alizadeh N, Salimi S, and Jabbari A. Transport study of palladium through a bulk hquid membrane using hexadecylpyridinium as carrier. Sep Purif Technol, 2002 28(3) 173-180. 

Gong S-L, Zhong Z-L, and Chen Y-Y. Calixcrown obgomers as cation carriers in a bulk hquid membrane. React Funct Polym, 2002 51 (2-3) 111-116. 

Jabbari A, Esmaeili M, and Shamsipur M. Selective transport of mercury as HgCl " through a bulk hquid membrane transport using K -dicyclohexyl-18-crown-6 as carrier. Sep Purif Technol, 2001 24(1-2) 139-145. 

Ghohvand MB and Khorsandipoor S. Selective and efficient uphill transport of Cu(II) through bulk hquid membrane using Al-ethyl-2-aminocyclopentene-l-dithiocarboxylic acid as carrier. J Mem Sci, 2000 180(1) 115-120. 

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