Columns construction materials

Table 4.6 gives some basic information on protein binding for common column construction materials. 

One of the most important advances in column construction has been the development of open tubular, or capillary columns that contain no packing material (dp = 0). Instead, the interior wall of a capillary column is coated with a thin film of the stationary phase. The absence of packing material means that the mobile phase... 

The above-mentioned space-time yields were referred solely to the reaction volume, i.e. the micro channel volume. When defining this quantity via an idealized reactor geometry, taking into accoimt the construction material as well, natarally the difference in space-time yield of the micro reactors from the laboratory bubble column becomes smaller. Still, the performance of the micro reactors is more than one order of magnitude better [38], The space-time yields for the micro reactors defined in this way ranged from about 200 to 1100 mol monofluorinated product... 

The reactivity of chemicals used in a process must be assessed, since these chemicals may become in contact in a desired way or accidentally during the process. These interactions are usually analysed in a triangular matrix where the desired and undesired reactions are marked at the intersection of each row and column. Beside chemicals or mixtures, the different fluids (i.e. heat carrier), waste streams, and construction materials must also be considered. An example of such a matrix, summarizing the safety data and the interactions, is represented in Figure 1.3. 

Because diffusion dominates the transport of contaminants in barriers and columns constructed of low-permeability materials, model calibrations and predictions are extremely sensitive to the form of the specified boundary conditions. Two issues are of particular importance 1) treatment of the entrance mixing zone in laboratory columns, and 2) specification of appropriate BCs to represent a slurry wall under field conditions. 

Similar to GC instruments, HPLC instruments consist of an injection port, a separation column, a detector, and an instrument control/data acquisition computer. The use of liquid as a mobile phase influenced the design and construction materials of HPLC instrumentation elements. A sample extract or an aqueous sample is introduced into the separation column through an injection loop that can be programmed to receive various volumes of liquid (5 pi to 5 ml). 

The efficiency can be varied by changing physical column parameters such as the length, diameter, and construction material of the container of the column. It can also be varied by changing chemical parameters such... 

The column is the heart of the chromatograph, providing the means for separating a mixture into components. The length, diameter, and construction material of the column affect the lifetime, efficiency, and speed of separation. The size and nature of the packing material affect resolution. 

In distillation of liquefied gases, raises boiling points of the column liquid. This allows cheaper construction materials to be used. 

Any incompatibility between a sensitive sample component and column support, liquid substrate, or construction material. 

Columns (distillation). In addition to the number of plates and operating conditions it is also necessary to specify the column diameter, materials of construction, plate layout, etc. 

Six tanks of different constructional materials and six different materials to be stored in these tanks are listed in the following columns ... 

Apparatus. A diagram of the custom built gas chromatographic instrument is shown in Figure 1. Because of the highly reactive and corrosive nature of C1F3, the construction materials tor the instrument were stainless steel, Monel, and nickel. The apparatus is best considered as four parts sample inlet system, column, detector, and detector bypass. 

When investigating the abstracts, an article should not be eliminated on the basis of a title alone for these are often deceptive. For example an article entitled The Utilization of Benzene may contain detailed information on its commercial production. An article entitled XYZ Company produces 180,000,000 million lbs. of ethylene may simply be an announcement that the plant is operating, but again, it may contain a highly detailed description of the plant itself, construction materials used therein, and results of operations. More Propane Recovery may be merely a half-column story stating that more propane is being recovered from a specific plant, but it could also be a highly technical article on how the result is accomplished. 

Column type Material of construction Column i.d. (pm) Particle size (pm) Column length (m) Flow-rate (pi min )... 

Por laboratory and semi-technical operation the packed column is the type chiefly employed in special cases use is made of plate columns constructed of glass, which, owing to the resistance of the material, are abo suitable for the distillation of corrosive substances. 

It should be noted that valve-plate columns with nominal widths of 50, 100, 2(X) and 300 mm have recently been employed for laboratory and pilot plant distillations [35a]. They are made in Czechoslovakia, the constructional material being Siuiax glass. They can be used at reduced pressures for distillate boding temperatures up to 115°C. 

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