Multi-component separation

Strategies for Multi component Separation Systems with Energy Integration," AlChE J. 20, No. 3, p 491, 1974a. 

The Thiele-Geddes method can be used for the solution of complex distillation problems, and for other multi-component separation processes. A series of programs for the solution of problems in distillation, extraction, stripping and absorption, which use an iterative procedure similar to the Thiele-Geddes method, are given by Hanson et al. (1962). 

The additive standards for the MS library were dissolved in a suitable solvent and a sample was injected into the GC/MS system, or a sample was transferred into an injection port liner as is done for real world samples. Additive standards were mn at temperature program rates of 10 °C or 15 °C due to the lack of the necessity for multi-component separation. The actual temperature program used is listed on each Total Ion Chromatogram (TIC). 

Different numbers of stages for each component must be used to account for individual band broadening (the main disadvantage of stage models), making it impossible to get a proper description of the elution behavior of every component in a multi-component separation. 

These essentially consist of a pair of closely spaced, vertical rectangular plates bounded on the sides by the electrodes. The sample and carrier buffer are fed from the top of the slit and travel down in laminar flow to a battery of fraction collectors at the bottom. Unlike the Philpot-Harwell device, which is essentially adiabatic, the thin-film separator can be cooled at the plates. The commercially available device, the Elphor , has a throughput of around 0.1 g/h of protein when operated for multi-component separation. It has been used to separate not only proteins, but cells and other particulate materials. Like the Philpot-Harwell apparatus, it uses a relatively large quantity of carrier buffer and the products are substantially diluted during separation. 

Multi-component separations can also be approximated with the graphical methods by selecting appropriate key components to define the separation. 

This chapter, as well as a few more that follow, is primarily concerned with a qualitative understanding of the factors that influence the separation process. The principles and ideas introduced in Chapters 2 through 6 and applied to idealized and binary systems are generalized here to multi-component separation. 

The column may be operated to meet various performance specifications within certain ranges. The variables that can be specified in multi-component separation include all the component compositions, rates, or recoveries in the two products as well as the product rates, properties, and temperatures, the reflux and boilup ratios, the condenser and reboiler duties, and the tray temperatures and liquid and vapor rates. 

Shortcut computation methods, including modular techniques for online real-time applications, are discussed, followed by a discourse on the major rigorous algorithms in use for solving multi-component separations. The application of these methods is detailed for the various types of multistage separation processes discussed earlier. The models are also expanded to cover column dynamics. 

In this section some basic features of nonlinear wave propagation in non-reactive and RD processes will be illustrated and compared with each other. The simulation results presented are based on simple equilibrium or non-equilibrium models [51, 65] for non-reactive separations. In the reactive case, similar models are used, assuming either kinetically controlled chemical reactions or chemical equilibrium. We focus on concentration (and temperature) dynamics and neglect fluid dynamics. Consequently, for equimolar reactions constant flows along the column height are assumed. However, qualitatively similar patterns of behavior are also displayed by more complex models [28, 57, 65] and have been confirmed in experiments [41, 59, 89, 107] for non-reactive multi-component separations. First experimental results on nonlinear wave propagation in reactive columns are presented subsequently. 

Agrawal, R. (1996). Synthesis of Distillation Column Configurations for a Multi-component Separation. Ind. Eng. Chem. Res., 35,1059-71. 

The idea of integrating the pretreatment beds in PSA has also been used in hydrogen purification, in which an inefficient sorbent in the pretreatment beds adsorbs pentane and heavier compounds, whereas the main beds adsorb methane, ethane, and propane (Alexis, 1967). This idea should be useful in many multi-component separations. 

When the production scale is relatively small, it is more benelieial to run the distillation process in batch mode. Batch distillation is commonly used in the line chemicals, specialty polymer, biochemical, pharmaceutical, and food industries. Only a single column is needed in batch distillation for multi-component separation, while a continuous distillation system requires multiple columns for such separation. In batch distillation, a single column can handle a wide range of feed compositions, various numbers of components, and various degrees of difficulty in the separation, thus providing great flexibility in the operation. 

Chapter 7 Multi-Component Separation Conventional Distillation... 

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