Extraction equilibria solvent effect

At pH 9.05, the phenol-phenolate equilibrium favours the phenol by a factor of 7 1, and the amine-ammonium ion equilibrium favours the amine by a factor of 7 1. In other words, the non-ionized morphine predominates, and this can thus be extracted into the organic phase. What about the amounts in ionized form are these not extractable By solvent extraction of the non-ionized morphine, we shall set up a new equilibrium in the aqueous phase, so that more non-ionized morphine is produced at the expense of the two ionized forms. A second solvent extraction will remove this, and we shall effectively recover almost all the morphine content. A third extraction would make certain that only traces of morphine were left as ionized forms. 

In these complicated extraction systems containing the polymeric and/or hydroxo species, one would expect the solvent used as a diluent to exert a considerable effect on the extraction equilibrium. In the extraction of gallium (III) with decanoic acid it has been found that the less polar the solvent, the more polymerized the extracted species (150). More recently, the solvent effect on the extraction (156) and dimerization (151, 153) of copper(II) decanoate has been interpreted according to regular solution theory (141,142). 

This result may be explained by a combination of intraparticle diffusion and bulk mass transfer processes. As material is extracted from the exposed areas of the seed, the solvent must travel further through the pores to reach the solute. Also, as the entrance portion of the bed becomes depleted of soluble components, the effective bed length decreases until the residence time is insufficient to achieve equilibrium. Similar effects were observed in seed oil extraction by Fattori (1) and Taniguchi et al. (9). 

Iron, tris(hexafluoroacetylacetone)-structure, 65 Iron, tris(oxalato)-chemical actinometer, 409 Iron, tris(l,10-phenanthroline)-absorptiometry, 549 racemization, 466 solid state, 467 structure, 64 Iron(O) complexes magnetic properties, 274 Iron(II) complexes magnetic behavior, 273 spectra, 253 Iron(III) complexes equilibrium constant solvent effect, 516 liquid-liquid extraction, 539 magnetic behavior, 272 spectra, 253 Iron(IV) complexes magnetic behavior, 272 Isocyanates metal complexes hydrolysis, 429 Isokinetic effect ligand exchange solid state, 469 Isomerism, 179-208 configurational, 180, 188 constitutional, 180,182 coordination, 183 detection, 180 history, 24... 

Nickel, tris( 1,10-phenanthroline)-racemization, 24,466 solid state, 467 structure, 64 Nickel(I) complexes magnetic properties, 274 Nickel(II) complexes, 470 allogonism, 207 equilibrium constants solvent effect, 516 isomerism, 184 liquid-liquid extraction, 544 magnetic properties, 274 5-mcrcaptoamine alkydation, 417 photoreactivity, 407... 

Wang and Wu [70] analyzed the extraction equilibrium of the effects of catalyst, solvent, NaOH/organic substrate ratio, and temperature on the consecutive reaction between 2,2,2-trifluoroethanol with hexachlorocyclotriphosphazene in the presence of aqueous NaOH. Wu and Meng [69] reported the reaction between phenol with hexachlorocyclotriphosphazene. They first obtained the intrinsic reaction-rate constant and overall mass transfer coefficient simultaneously, and reported that the mass transfer resistance of QX from the organic to aqueous phase is larger than that of QY from the aqueous to organic phase. The intrinsic reaction-rate constant and overall mass transfer coefficients were obtained in three ways. 

Separation of extract and solvent by changing temperature depends on the variation of equilibrium solubility of the extract in the solvent. The effectiveness can be concluded from phase equilibrium. In general, a change of temperature will not be effective enough to clean the solvent sufficiently for reuse in the extracting process. But change in temperature can well be applied in addition, or if total regeneration of the solvent is not necessary. 

A theoretical or equihbrium stage is a device or combination of devices that accomplishes the effect of intimately mixing two immiscible liquids until equilibrium concentrations are reached, then physically separating the two phases into clear layers. Crosscurrent extraction (Fig. 15-4) is a cascade, or series of stages, in which the raffinate R from one extraction stage is contacted with additional fresh solvent S in a subsequent stage. 

FIG. 15-8 Effect of temperature on ternary liquid-liqmd equilibrium. A feed solvent, B = solute, and S = extraction solvent. 

Study the effect of the extraction stage on reactor performance by varying the magnitudes of the the mass transfer coefficient Ka, the equilibrium distribution ratio m, the recycle ratio R, the relative reactor and extraction volumes and solvent flowrate. 

The effect of inert solutes, such as calcium chloride, magnesium chloride and sucrose, can also be employed judiciously and efficaciously in the development of solutions to difficult extraction problems by allowing efficient extractions from the water into such solvents as acetone, ethanol and methanol that are found to be completely miscible with water in the absence of salt. Matkovitch and Cristian found the above three inert solutes to be the best agents for salting acetone out of water. It has been observed that the acetone layer that separated from a saturated aqueous solution of CaCl2 exclusively contained 0.32 0.01% water (v/v) and 212 ppm salt (w/w) at equilibrium. 

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