Applications of Thermodynamics in Separation Technology

For solving the tasks mentioned above, reliable experimental pure component properties (vapor pressures, densities, heat capacities, transport properties, etc.) and mixture data (phase equilibria, and excess properties) for the system considered would be most desirable. Some decades ago, a time-consuming literature search was always necessary to obtain these data. In the meantime comprehensive factual data banks, for example, the Dortmund Data Bank (DDB), NIST data bank, DIPPR data bank, and so on, have been built up. These data banks contain a great part of the worldwide available experimental data. 

From the data banks mentioned before, theDIPPRdatabank covers experimental pure component properties for approx. 2000 selected compounds. Additionally, recommended basic data and temperahire-dependent correlation parameters for the various pure component properties are available for aU compounds. When experimental pure component data were missing in the DIPPR data bank, predictive methods were used to calculate the required pure component data and to fit the required temperature-dependent correlation parameters. 

In the DDB and in the NIST data bank, additionally the various mixture data (phase equilibria, excess properties, transport properties, etc.) are stored besides the pure component properties. While the NIST data bank mainly contains the data from important thermodynamic journals, in the DDB additionally an enormous amount of unpublished experimental data from private communications, PhD, MSc, BSc theses, and data from industry were collected besides the data from scientific journals published worldwide in various languages. Furthermore, a great 

Chemical Thermodynamics for Process Simulation. First Edition. 

Jiirgen Gmehling, Barbel Kolbe, Michael Kleiber, and Jflrgen Rarey. 

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Certain techniques for the application of thermodynamics in separation technology are introduced in Chapter 11, for example, the concept of residue curve maps, a general procedure for the choice of suitable solvents for the separation of azeotropic systems, the verification of model parameters prior to process simulation and the identification of separation problems. 

I 11 Applications of Thermodynamics in Separation Technology respect to benzene ... 

Thermodynamic behaviors and retention mechanisms for SFC are unique. Low temperatures and high pressures or high densities usually favor fast separation of enantiomers in SFC. In the case that the isoelution temperature is below the working temperature, the selectivity increases as temperature increases and higher temperatures are favorable for chiral separation. Future development in SFC will likely include new chiral column technologies and instrumentation refinement. A greater variety of chiral columns packed with smaller particles will open up more areas of application for fast chiral separations. In addition, improvement in signal-to-noise ratio of... 

There are ample books in the literature considering in detail the thermodynamics of polymer solutions, i.e. the state of the P-I-LMWL system above the 9 point (for systems with an upper critical solution temperature) (see the bibliography). With the exception of riory (J953) and Tompa (1956), the other authors cither did not deal with phase separation or mentioned it only in its relation to fractionation. A need has, therefore, arisen to look into the questions of liquid-liquid phase separation (including multiphase separation) as c.arefully as possible, the more so that many applications of these problems can be introduced into the technology of polymer materials. 

As anticipated in the Introduction, the application of membrane reactors for power and/or hydrogen production is now discussed. The advantages of membrane reactors in these applications include simultaneous fuel conversion and hydrogen separation, leading to thermodynamic advantages and potential equipment savings compared to conventional technologies. 

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