Extract composition

If the feed, solvent, and extract compositions are specified, and the ratio of solvent to feed is gradually reduced, the number of ideal stages required increases. In economic terms, the effect of reducing the solvent-to-feed ratio is to reduce the operating cost, but the capital cost is increased because of the increased number of stages required. At the minimum solvent-to-feed ratio, the number of ideal stages approaches infinity and the specified separation is impossible at any lower solvent-to-feed ratio. In practice the economically optimum solvent-to-feed ratio is usually 1.5 to 2 times the minimum value. 

Example 2 Stage and Composition Calculation A 100-kg/h feed stream containing 20 weight percent acetic acid in water is to he extracted with 200 kg/h of recycle MIBK that contains 0.1 percent acetic acid and 0.01 percent water. The aqueous raffinate is to he extracted down to 1 percent acetic acid. How many theoretical stages wiU he required and what will the extract composition he ... 

The mix point, = 0.0673, falls on a straight line connecting x and The extract composition is then determined hy drawing a straight line from x,-throiigh Zm until the line intersects the extract line at the final extract composition, i/e = 0.084. The delta point is then found at the intersection of two lines. One line connects the feed and extract compositions x and y. The other line connects the raffinate and solvent compositions x,- and y. ... 

Table II. Carbohydrate compositions (weight percentage) of individual oligomer peaks purified (QAE-Sephadex or HPLC ion-exchange separation, respectively) from mixtures of citrus pectin oligomers or B fruit extracts Compositions shown are for peaks whose biological activity is described in Figure 4. Uronic acid values are based on colorimetric assay. Proportions of neutral sugars were determined by GC and adjusted so that totals equal 100%. In fact, some oligomers (G7 peaks 8, 9 and 10. B extract peak 10) produced small (less than 1 % of the total integrated area), unknown peaks in the GC chromatograms.

Draw a line from rm through the point 0. This will cut the curve at the final extract composition, e. ... 

Note if the extract composition is specified, rather than the raffinate, draw the line from e through 0 to find rm. 

Draw a line through from the pole point P through r, to find the point on the curve giving the extract composition leaving the second stage, e2. 

A paper by Kasprow et al.42 is important because it shows the realization that starting materials need to be analyzed on a routine basis just as with reaction products. Kasprow et al. discuss the correlation of fermentation yield with the yeast extract composition as seen by NIR. Using PLS for the correlations, models were constructed with a correlation of 0.996 and a standard error of 1.16 WSW. The authors used the models to predict yields, using different lots of yeast, and were quite satisfied with the results. 

Table 8.5 C4 Olex process typical feed and extract composition.

Table 8.6 Typical Sorbutene process feed and extract compositions.

Irradiated UO2 is dissolved in nitric acid, resulting in a dissolver solution with the approximate composition listed in Table 12.7. This is treated by the Purex process. The main steps in the conventional Purex process are shown schematically in Fig. 12.5. All existing plants listed in Table 12.8 use some variation of the Purex process. Typically, the extractant composition (percentage TBP, diluent) and the extraction equipment (i.e., pulse columns, mixer-settlers, etc.), vary from plant to plant. However, the upper concentration limit is 30% TBP to prevent a phase reversal due to the increased density of the fully loaded solvent phase. 

The example of a total extract composition of a tropical soil from the Amazon, Brazil, shows mycose as the major compound, numerous other monosaccharides, lipid components such as fatty acids and fatty alcohols, and natural product biomarkers (Fig. 9a). The mycose and elevated levels of the other saccharides reflect the efficient fungal/microbial degradation of plant detritus in the tropics. This can be compared to the saccharides in the soil from an almond orchard in California, where glucose and mycose are the main sugars with lipids, sterols and triterpenoids (Fig. 9b, ). 

The quantity (y — y) is the over-all driving force expressed in terms of extract compositions, as shown in the figure. The over-all number of extract transfer units NtoE for the extraction is then defined by integration of Eq. (9), assuming KEa remains constant ... 

If, in the foregoing example, there had been no reflux and the same solvent dosage had been applied, the final extract composition would have been limited to that shown at point /e. If, on the other hand, we had been required to make an extract of composition E, it would have been necessary to utilize a lower solvent dosage and a larger number of theoretical stages. 

Prior to metabolomic analysis, sample treatment is typically needed, as CSF contains approximately 0.3 mg/mL protein (114) that may hinder metabolite analysis. Consequently, CSF sample treatment is essentially directed to protein removal by means of organic solvent addition (84,88) or by ultrafiltration (85,89,90). The final metabolic extract composition will depend in a great extent on the sample treatment (115), and it will be selected mostly regarding the metabolomic approach and the analytical technique that will be afterward applied. 

Conversions between 42-68% were obtained for supercritical water extraction of Victorian brown coals at 380°C and 22MPa, considerably higher than using toluene under the same conditions. The conversions obtained with a bituminous and a sub-bituminous coal were much lower. Pressure had a marked effect on both the conversion and the extract composition, whereas temperature had only a slight effect. Considerably higher conversions were achieved using dilute sodium hydroxide rather than water. The composition of the products is discussed. 

Figure 2. Extract composition for water (and toluene) extractions of brown coals at 380°C and 22MPa.

The investigation of a series of model meat systems has demonstrated the important role of volatile sulfur-containing heterocyclic components substituted with sulfur in the 3-position. One of these 3-substituted sulfur compounds, 2-methy1-3-methy1thio-furan was identified recently in the volatiles from cooked beef aroma (5J and from a heated yeast extract composition (6J and is considered a meaty character impact compound. 

In the graphical example shown in Fig. 2, interphase equilibria are shown by dashed tie-lines connecting the raffinate and extract compositions. As the mass fraction of C is increased, the tie-lines become shorter until the limit of miscibility is reached at the point P on Fig. 2. 

Since the point M lies in the two-phase region of the triangular diagram, the term mixture applies only on a scale larger than the size of the droplets formed. The droplet dispersion formed by agitation has sufficient interfacial area (see Section I.C) for equilibrium to be reached quickly, so that point M represents the mean of the extract composition (point E) and the raffinate composition (point R) which are connected by the appropriate tie-line. A further application of the inverse lever rule permits calculation of the relative amounts of extract and raffinate. In this example, the material balance based on 1 kg of feed is summarized as follows ... 

The comparison between the extract mass during the extraction (10 %) and the desorption (1.25 %) shows us that other effects than solubility are more crucial in the desorption process. The butylacetate regeneration is better than xylene regeneration zeolithe is saturated by a mixture composed with butyl acetate (50 %) and xylenes isomeres (30 %), the extracts composition is butyl acetate (60-65 %) and xylenes isomers (35-40 %). The equilibrium thermodynamic and adsorption data could help us to explain these results. To increase the C02 flow rate (Figure 3) contribute to decrease the desorption time but the lowest flow rate does not permit to desorbe completely zeolithe this is suggestive of a film transfer resistance at lower flow rates. 

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