Column Configurations

The derivation of Eq. (13-28) assumes a single-feed column and no sidestream. However, the same result is obtained for other column configurations. Typical 9-line constructions for sidestream stages are shown in Fig. 13-33. Note that the 9 hne for a sidestream must always intersect the diagonal at the composition (91 or Xi) of the sidestream. 

Differences have been observed in the performance of end- and center-fed column configurations. Consequently, discussions of center- and end-fed column crystallizers are presented separately. The design and operation of both columns are reviewed by Powers (Zief and Wilcox, op. cit., p. 343). A comparison of these devices is shown on Table 22-3. 

Pigure 3.1 shows several potential on-line modes of two-dimensional GC operation. These couplings demonstrate HRGC-HRGC performed by using a single heart-cut from the primary to the secondary column, multiple heart-cuts, transferred to multiple intermediate traps, and heart-cuts transferred to a multiple parallel secondary column configuration. 

Figure 3.1 Two-dimensional gas clnomatography instmmental configurations (a) direct ti ansfer heart-cut configuration (b) multiple parallel ti ap configuration (c) multiple parallel column configuration.

A five-column configuration of Such an analyser system is depicted in Figure 14.6. The first event in the process is the analysis of Hj by injection of the contents of sample loop 2 (SL2) onto column 5 (a packed molecular sieve column). Hydrogen is separated from the other compounds and detected by TCD 2, where nitrogen is used as a carrier gas. The next event is the injection of the contents of sample loop 1 (SLl), which is in series with SL2, onto column 1. After the separation of compounds up to and including C5, and backflushing the contents of column 1, all compounds above C5 (Q+) are detected by TCDl. The fraction up to and including C5 is directed to column 2, where air, CO, COj, Cj, and 2= (ethene) are separated from... 

The resolution of the bi-naphthol enantiomers was used for simulation purposes. A reference case relative to a 8-column configuration of the SMB, based on the values of operating variables and model parameters shown in Table 9-4 was chosen. 

Columns Configuration 2 columns per section Column diameter 2.6 cm Column length 10.5 cm... 

Topics which will be presented in this chapter include the hardware, software, automation, valve and column configurations, and integration used in comprehensive 2DLC. Aspects of the 2DLC experiment in conjunction with multichannel detectors such as UV diode array optical detectors and mass spectrometers are discussed along with the handling of the data, which is expected to expand in scope in the future as chemometric methods are more widely used for data analysis. 

Tanaka and co-workers [24] recently published a review on the development and availability of monolithic columns that describe the initial synthetic processes and actual column configurations generally adopted. 

Careful selection of equipment used to carry out chromatography is as important as the selection of the technique itself. Flexibility, ease of manipulation and ability to automate are important. Different techniques have different requirements for column configuration, all require the maximum throughput for process efficiency and economy, and benefit from automation of the individual process steps. 

Figure 6.28. Simplified schematics of practical dual detector and/or column configurations.

Figure 15.4 Schematic overview of the two-dimensional separation system (A) and a detailed view of the post-column configuration (B) according to Link (1999).

Process synthesis and design of these non-conventional distillation processes proceed in two steps. The first step—process synthesis—is the selection of one or more candidate entrainers along with the computation of thermodynamic properties like residue curve maps that help assess many column features such as the adequate column configuration and the corresponding product cuts sequence. The second step—process design—involves the search for optimal values of batch distillation parameters such as the entrainer amount, reflux ratio, boiler duty and number of stages. The complexity of the second step depends on the solutions obtained at the previous level, because efficiency in azeotropic and extractive distillation is largely determined by the mixture thermodynamic properties that are closely linked to the nature of the entrainer. Hence, we have established a complete set of rules for the selection of feasible entrainers for the separation of non ideal mixtures... 

Agrawal R. Synthesis of distillation column configurations for a multicomponent separation. Ind Eng Chem Res 1996 35 1059. 

Figure 4.13. Schematic diagrams of large-volume injection systems. Top on-column configuration with solvent vapor exit. (Drawing courtesy of Agilent Technologies.) Bottom programmed temperature vaporization configuration. (Drawing courtesy of ATAS, International.)...

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