Extraction capacity

H values are proportional to the heat-extracting capacity of the medium. 

Extraction and Extractive Distillation. The choice of an extraction or extractive distillation solvent depends upon its boiling point, polarity, thermal stabiUty, selectivity, aromatics capacity, and upon the feed aromatic content (see Extraction). Capacity, defined as the quantity of material that is extracted from the feed by a given quantity of solvent, must be balanced against selectivity, defined as the degree to which the solvent extracts the aromatics in the feed in preference to paraffins and other materials. Most high capacity solvents have low selectivity. The ultimate choice of solvent is deterrnined by economics. The most important extraction processes use either sulfolane or glycols as the polar extraction solvent. 

Yosida et al. [41] found that p-t< rr-butylcalix[6]ar-ene can extract Cu from the alkaline-ammonia solution to the organic solvent. Nagasaki and Shinkai [42] described the synthesis of carboxyl, derivatives of calix-[n]arenes ( = 4 and 6) and their selective extraction capacity of transition metal cations from aqueous phase to the organic phase. Gutsche and Nam [43] have synthesized various substituted calix[n]arenes and examined the complexes of the p-bromo benzene sulfonate of p-(2-aminoethyl)calix[4]arene with Ni, Cu , Co-, and Fe. ... 

Since its commercialization in 1989, the number of gasoline Molex units designed and commissioned has risen to 13, with a total extraction capacity of over 2080 KMTA (= x lOH/year). 

To allow a higher extraction capacity (net transfer) and avoid the influence of liberated H ions, simultaneous neutralization with NaOH directed into the mixer is used. Such an example is described later, where nickel is extracted from a cadmium electrolyte. Other means of controlling the pH includes the use of acid extractants in either alkaline (NH R) or neutral (Na R) form. 

The most commercially important mechanism of all is the kinetics of solute transfer from an aqueous to a reverse micelle phase. The kinetics of extraction of metal ions have not received the same research attention as the extraction capacity of W/O microemulsions. As the mechanism of extraction of metal ions is chemical, the effect of creating a microemulsion in an organic phase that contains the reactant can be measured experimentally. Results indicate that, as in the case of extraction equilibrium, the rate of extraction may increase substantially by the presence of the microemulsion as compared with the conventional system [20,38,44] or decrease it to... 

Rozen, A.M. Nikolotova, Z.I. Relation of the extraction capacity of organic compounds to their structure and to the electronegativity of the substituting groups. Zh. Neorg. Khimii (Russ.) 1964, 9 (7), 1725-1742. 

Y. Sasaki, Y. Sugo, S. Suzuki, and T. Kimura. A method for the determination of extraction capacity and its application to N,N,N, N -tetraalkyl derivatives of diglycol-amide-monoamide/n-dodecane media. Anal. Chim. Acta, 543(1-2) 31—37, 2005. 

M REC, as the TREC, does not depend on the reaction path. In addition, there is no dependence on the membrane-permeation properties (related to the time required for species permeation).1 In any case, the final value reached depends on the extractive capacity of the system, for example, the pressure and composition on the permeate side. The composition on the permeate side, similarly to the feed molar ratio, can be expressed by considering the ratio (named sweep factor) between the initial molar number of nonpermeating species (present on the permeate side) and the initial molar number of the reference reactant, for example, methane for methane steam reforming, or carbon monoxide for water gas shift). The sweep factor was defined for a closed M Ras ... 

In 1982 the first directive in the sector, Council Directive 82/711/EEC, laying down a precise reference framework for the system of checking specific and/or overall migration, was adopted. It establishes what simulating liquids (i.e. liquids which can simulate the extractive capacity of foodstuffs), contact times and temperatures are to be used in migration tests performed under standardized conditions. This reference framework, which may seem unduly rigid given the innumerable conditions of contact in reality, was made flexible by the inclusion of a clause which permits Member States to depart from the standard conditions where these prove to be inadequate in the case in question either for technical reasons or because they are too different from the real conditions. 

Only the simulant indicated by an X may be used. When X is followed by an oblique stroke and 3 or 5 , the result of the migration tests should be divided by the number indicated, known as the reduction factor . This figure is conventionally used to take account of tbe greater extractive capacity of the simulant for fatty foods compared with other types of foods. 

Accumulation of electrolyte decomposition products. This phenomenon leads to blocking of ion flow near nonconductive precipitates which reduce the ability to extract capacity from microregions. Current densities build up in the remaining regions and enhance other nonideal phenomena as discussed above. 

Another polymer that is suitable for the extraction of Hg(n) and Ag(i) but does not have the extraction capacity as that of Baumann s polymer 48-68% and 39-68% for Hg(n) and Ag(i), respectively. Yamashita et al. reported a regeneration procedure of the extracting polymer in which the polymer after treatment with 3moll-1 ammonium hydroxide was reused <1996RFP47>. 

Supercriticial Solvents. Although it was known in 1879 that supercritical fluids had solvent properties (180), supercritical extraction was not extensively developed until the early 1980s. This method uses organic or inorganic compounds as solvent, at or usually above their critical temperature and pressure where they are known as supercritical fluids. In a supercritical fluid state, common gases such as carbon dioxide have the properties and extractive capacity of a liquid. The compound most used in supercritical extractions is carbon dioxide. Carbon dioxide can exist as a gas, liquid, or solid, depending on pressure and temperature conditions. However, at or above its critical point. CO2 can only exist as a supercritical fluid. 

The distribution coefficients for benzene and toluene with thietane 1-oxide was compared with those of other sulfoxides aqueous thietane 1-oxide has a greater extraction capacity than dimethyl sulfoxide. 

For a compound for which the organ has a high extraction capacity, the exiting concentration is very... 

As an example, let us take the simplest dioxide of the first group, i.e. tetraphenylmethylenediphos-phine dioxide (Ph)oP(0)CH2P(0) (Ph)2 (I) and trace the effect of modifications in its structure on the extracting capacity with respect to TPE and Eu. 

Ph)2P(0)C(=CH2)P(0)(Ph)2 (X) has been found to decrease the extraction capacity in all the instances. Substituents of the methylene bridge hydrogen take no part in formation of compounds being extracted but, according to the induction properties, affect their stability. 

Also studied was the extraction capacity of another group of reagents (VI,), i.e. 

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