Column calculation

The last column, calculated according to Equation 10-15, is of particular interest because it relates the standard counting error to the amount present of the element sought (on the simplifying assumption, of course,... 

MURPHREE, E. V. Ind. Eng. Chem. 17 (1925) 747. Rectifying column calculations — with particular reference to N component mixtures. 

Katz et al (1) also examined the effect of particle diameter on the value of the overall resistance to mass transfer constant (C) They employed columns packed with 3.2 i, 44., 7 8 i, and 17.5 i, and obtained HETP curves for the solute benzyl acetate in 4.3%w/w of ethyl acetate in n-heptane on each column. The data was curve fitted to the Van Deemter equation and the values for the A, B and C terms for all four columns calculated. According to the Van Deemter equation the (C) term should be linearly related to the square of the particle diameter. 

In the next column calculate the normalized cumulative frequency, f= cumulative frequency/(n + 1). 

Interstitial velocity of carrier gas. u. The linear velocity of the carrier gas inside a packed column calculated as the average over the entire cross section. Under idealized conditions it can be calculated as ... 

Fig. 4.22. Trickle-bed reactor, (a) Schematic diagram showing individual mass transfer steps for a hydrogenation process (b) profile of dissolved hydrogen in the liquid flowing down the column, calculated in Example 4.8...

Table 5. Reversible and perturbated rate constants kg and k, resp., of the rediffusion of polystyrene from gel into sol of the PDC-column, calculated from Eqs. (16 b) and (21)...

The composition of the tail-gas stream from the absorber can now be calculated. Calculations are based on an overall mass balance, and also on a mole basis for each element. The assumption made is that the tail gas is saturated with water upon leaving the column. Calculations were performed using an electronic programmable calculator. 

According to the position of the sampling points, the results of the analysis are assigned to a value matrix for the practical application of the univariate two-way analysis of variance. Thus, rows and columns can be defined. As a result of the calculation, the Z7-values of the corresponding features for rows and columns calculated by... 

HF/6-31G /MP2(fc)/6-31G, respectively, the mean of nine errors for each method is 3.0/2.3/1.9. Errors are given in the Errors column as HF/3-21G< )/HF/6-31G /MP2/6—31G A minus sign means that the calculated value is less than the experimental. The numbers of positive and negative deviations from experiment and the average errors (arithmetic means of the absolute values of the errors) are summarized at the bottom of the Errors column. Calculations are by the author, references to experimental measurements are given for each measurement. Some molecules have calculated minima at other dihedrals in addition to those given here, e.g. FCH2CH2F at 180°. Errors are presented HF/3-21G( VHF/6-31G /MP2/6-31G. a[lg], pp.151, 152... 

Octanol/Air Partition Coefficient, log KoA at 25°C or as indicated and reported temperature dependence equations 9.27 8.68 (generator column calculated-KoW/KAW, Komp McLachlan 1997a) log KqA = -6.50 + 4700/(T/K), temp range 10-43°C (Komp McLachlan 1997a)... 

Figure 24. Effects of temperature and isotopic substitution on the spectral densities of crystalline adipic acid in the absence of Fermi resonance. Comparison between theoiy (Eq. (279)) (thick Line) and experiment [101] (grayed spectra). Left column calculations using the breaking of the IR selection rule (r)° = 0). Right column same calculations but without the breaking of the IR selection rule (r 0 = 0).

Solute is introduced into a chromatographic column as a squareshaped concentration pulse, which occupies an initial width w on the column. Calculate the second moment about the mean (the variance a2) in terms of w. Calculate [Pg.109]

Before the 1950s, column calculations were performed by hand. Although rigorous calculation procedures were available, they were difficult to apply for all but very small columns. Shortcut methods were therefore the primary design tool. Rigorous procedures were only used for small columns or for final design checks. Inaccuracies and uncertainties in the shortcut procedures were usually accommodated by overdesign. 

Despite occasionally high concentrations and dominance of Phaeocystis spp. in the water column, calculations based on sediment-trap measurements suggest low daily loss rates, implying high retention of Phaeocystis cell carbon in the upper 50-100 m. Unless deep mixing accelerates vertical export, the contribution to the vertical carbon flux at 100 m is on average 3%. The conclusion is that Phaeocystis cell carbon does not contribute significantly to vertical carbon export. 

Figure 3 gives the relative volatility profiles also for the sample column calculation these correspond to the temperature and composition profiles of Figures 1 and 2. Pentane is easily separated from ethanol while water is not as readily separated in the bottom of the column, reboiler to tray 5. The pentane volatility decreases and that of water increases rapidly, relative to ethanol, on proceeding from tray 5 to 8. They remain nearly constant for the next nine trays where the separation of water relative to ethanol is favorable the separation of pentane relative to ethanol is still favorable in this region. On the top tray conditions are favorable for separating water, but for separating pentane they are less favorable. 

Calculate the eolumn height, Z, from Equation 6.21.7T for tray columns. For packed columns calculate Z from Equations 6.21.7P and 6.21,9P. 

First, pseudocomponents determined by the quadrature method may well be unrealistic ones for instance, if the label x is (proportional to) the number of carbon atoms, pseudocomponents may well correspond to noninteger jcjc values. This may be aesthetically unpleasant, but it does not represent a real problem. More seriously, the appropriate pseudocomponents obviously depend on the composition and, hence, in a repeated calculation such as is required in a distillation tower, pseudocomponents will need to be different at each step. This puts out of tilt the mass balance equations that are coupled to the equilibrium ones, and, even if this problem could be circumvented (as, at least in principle, it can), the procedure would certainly not be applicable to existing software for distillation column calculations. 

This column is experimental average from Reference 20, other columns calculated via Eq. (10.5). (See also footnote e of Table 10.7.)... 

Figure 16.14 Comparison between calculated and experimental band profiles for a 1 1 mixture of phenetole and n-propyl benzoate on a Symmetry-Cig column. Calculations made with the TD model. Solid symbols ( ), experimental data solid line, calculated profile. The empty triangular symbols show the single-component band profile of n-propyl benzoate, for the sake of comparison. The inset shows the corresponding calculated single- component profiles. Cl = 9.28 g/dm and Cx = 9.28 g/dm tj j = 60 s. Reprinted from W. Pi tkowski, D. Antos, F. Gritti, G. Guiochon,. Chromatogr., 1003 (2003) 73 (Fig. 7).

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