Phenol separators

To hydrolyse an ester of a phenol (e.g., phenyl acetate), proceed as above but cool the alkaline reaction mixture and treat it with carbon dioxide until saturated (sohd carbon dioxide may also be used). Whether a solid phenol separates or not, remove it by extraction with ether. Acidify the aqueous bicarbonate solution with dilute sulphuric acid and isolate the acid as detailed for the ester of an alcohol. An alternative method, which is not so time-consuming, may be employed. Cool the alkaline reaction mixture in ice water, and add dilute sulphuric acid with stirring until the solution is acidic to Congo red paper and the acid, if aromatic or otherwise insoluble in the medium, commences to separate as a faint but permanent precipitate. Now add 5 per cent, sodium carbonate solution with vigorous stirring until the solution is alkaline to litmus paper and the precipitate redissolves completely. Remove the phenol by extraction with ether. Acidify the residual aqueous solution and investigate the organic acid as above. 

The technical method for obtaining phenol is by shaking out with caustic soda the middle oil of the coal-tar distill ate,. after some of the naphthalene has crystallised out. The phenol dis-soKes m the alkali, and is then lemoved fiom insoluble oils. The alkaline liquid is acidified, the phenol separated, distilled, and finally purified by freezing. 

These data show clearly that the structure-property relationships which apply to hydrophobic organic chemicals such as the chloro- and alkyl-aromatics also apply to the phenols, but the relationships are more scattered and less well defined. The absolute values of properties differ greatly. This scatter is probably attributable, in part, to insufficient experimental data or errors in experimental measurements, to dissociation and to the greater polar character of these chemicals. It is not recommended that correlations developed for non-polar organic chemicals be applied to the phenols. Separate treatment of each homologous series is required. 

Water and waste water Phenols separated on a Nova-Pak Phenyl column eluted with ammonium acetate acetonitrile LC-ED 0.5 mg/L 91-100% Paterson et al. 1996... 

B CR depressed in seme circumstances, total phenolics not well correlated to this but protein-ccrrplexing phenolics are (p<0.002). N.B. Resins, TP, and protein ccxtplexing phenolics separately measured. 

Water-saturated phenol/chloroform is prepared in the following way. Phenol is fused by heating the botde in hot water (55-60°C). After addition of an excess amount ofwater, they are mixed well and left to allow separation of water from the mixture at room temperature. After water-phenol separation, the same amount of chloroform as the water-saturated phenol is added. These are then mixed well and left again to allow separation. Use the lower layer for phenol/ chloroform extraction. The upper water can be discarded if the volume is too excessive. 

An aqueous solution of the substance is gently warmed, when a vigorous evolution of nitrogen occurs, and a dark coloured oil, smelling strongly of phenol, separates. It can be extracted with ether and tested for phenol (see Preparation 352). 

The discovery of TS 1 led rapidly to the development of a process for phenol hydroxylation (25). This process has numerous advantages over the previous processes using peracid or Co2+, Fe2+ as catalysts higher conversion of phenol (30% instead of 5-9%) requiring less phenol separation/recycle steps, comparable or higher yields relative to both hydrogen peroxide and phenol, wider range of catechol/hydroquinone ratio (0.5-1.3 instead of 1.2-1.5 or 2.0-2.3) (24, 26). 

Partial condensers, 24, 341 Partial reduction, 79, 113 Patent blues, 301 Permanent red 2G, 267 Phenanthrene, 1 Phenol, 51, 86 from chlorobenzene, 76, 88 technical observations, Phenolphthalein paper, 395 Phenols, separation, 30 Phend-o-svdfonic acid, 51 Phenol-m-sulfonic acid, 144,145... 

The phenol is present in the fusion product as the potassium salt formed by neutralization of the acid phenol with the excess of alkali. On acidifying the phenol separates and at the same time sulphur dioxide is evolved proving that a salt of sulphurous acid is present. The relation of this reaction to the sulphonic acids and to sulphurous acid has been discussed in connection with the sulphonic acids (p. 520). 

In Cig-bonded silica RP sorbents, the number of free silanol groups is very important in the attainment of phenolic separations. Silva et al. showed that Cig non-end-capped columns are more suitable for the recovery of several phenolic acids and flavonoids than the Cig end-capped ones. An enhanced recovery was obtained when 1% of methanol was added to the samples. 

Fig. 5-53. Separation of various mono- and polyvalent phenols. - Separator column Ion Pac NS1 (10 pm) eluent (A) 0.01 mol/L KH2P04 (pH 4.0) / acetonitrile (90 10 v/v), (B) 0.01 mol/L KH2P04 (pH 4.0) / acetonitrile (20 80 v/v) gradient linear, 15% B in 20 min to 55% B flow rate 1 mL/min detection UV (280 nm) injection volume 50 pL solute concentrations 100 ppm each of pyrogallic acid (1), resorcinol (2), phenol (3), o-cresol (4), 2,4-di-methylphenol (5), /J-naphthol (6), 2,4-dichloro-3-nitrophenol (7), and thymol (8).

The yields, relative to both hydrogen peroxide and phenol, were superior to those of the homolytic and acidic catalysts already used in commercial processes (Table 1) [5,6]. TS-1 enabled the more efficient use of a relatively expensive oxidant and minimized the need for phenol separation/recycle steps. The reaction conditions and the results of a number of studies are given below (Table 2) [2,7-10]. 

Boyadzhlev et al. (78) discussed phenol extraction using a combined ELM and film pertractlon scheme. Volkel et al. (79) discuss an interesting application. They used an enzyme encapsulated in an ELM to remove phenol from blood. Kitagawa et al. ( ) discussed applications of the liquid membrane technique to the removal of ammonia and various metal ions from Industrial waste water. For ammonia removal, the formulation used was similar to that for phenol separation except that the trapping agent was an acid. Various commercial... 

Caustic soda solution Percolation with caustic Phenol-loads activated desorption of solvent Phenol separation with... 

Extraction with Organic solvents Caustic soda solution Supercritical gases Exiiaetion with earbon disulfide or other solvents Percolation with eaustie soda e.g. extraction with supercritical CO2 Sulphur extraction Sulfosorbon process Phenol-loads activated earbon Organic compounds Desorbate treatment by distillation, steam desorption of solvent Phenol separation with subsequent purging S aration of C02/or-ganic compounds... 

Analysis of the data reveals that the system is very effective for the rejection of polynuclear artxnatic hydrocarbons and much less effective for phenols. Separated in this fashion, rejection for the PAHs averaged 92% over the six days while rejection for the phenols averaged 18%. 

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