Liquid alcohol systems

Najdanovic-Visak, V. et al.. Pressure, isotope, and water co-solvent effects in liquid-liquid equilibria of (ionic liquid + alcohol) systems, /. Phys. Chem. B, 107, 12797, 2003. 

The solvated electron was observed to be an intermediate in the reaction of sodium with solid alcohols at 77° K by optical and ESR techniques [114]. It is now known to be generated in the sodium—liquid alcohol system [115]. The formation of the solvated electron was demonstrated by using dinitrogen monoxide as the electron scavenger, when nitrogen was formed. The hydrogen is evolved via an intermediate (eroiv)2 as might be the case in water. 

Both high bulk and surface shear viscosity delay film thinning and stretching deformations that precede bubble bursting. The development of ordered stmctures in the surface region can also have a stabilizing effect. Liquid crystalline phases in foam films enhance stabiUty (18). In water-surfactant-fatty alcohol systems the alcohol components may serve as a foam stabilizer or a foam breaker depending on concentration (18). 

As a solid dissolves in a liquid, atoms or molecules leave the solid and become part of the liquid. These atoms or molecules may carry no charge (then they are electrically neutral) or they may be ions. The iodine-alcohol system is of the... 

Shape selective catalysis as typically demonstrated by zeolites is of great interest from scientific as well as industrial viewpoint [17], However, the application of zeolites to organic reactions in a liquid-solid system is very limited, because of insufficient acid strength and slow diffusion of reactant molecules in small pores. We reported preliminarily that the microporous Cs salts of H3PW12O40 exhibit shape selectivity in a liquid-solid system [18]. Here we studied in more detail the acidity, micropore structure and catal3rtic activity of the Cs salts and wish to report that the acidic Cs salts exhibit efficient shape selective catalysis toward decomposition of esters, dehydration of alcohol, and alkylation of aromatic compound in liquid-solid system. The results were discussed in relation to the shape selective adsorption and the acidic properties. 

An established school preparation of 2-propanone (acetone) involves the small-scale (and rather exothermic) oxidation of the alcohol with dichromate(VI). It was observed in several laboratories that when the acidified dichromate solution was added to the alcohol in small portions (1-2 cc) rather than dropwise as specified, small sparks or incandescent particles were produced which sometimes survived long enough to escape from the neck of the flask. This also happened if the alcohol and/or the oxidant solution were diluted with extra water, with old or new samples of alcohol, and if air were displaced from the flask by carbon dioxide. It is therefore important not to exceed the specified dropwise rate of addition of oxidant solution. It is very unusual for glowing particles to be produced from a homogeneous liquid reaction system. 

American Society of Mechanical Engineers (ASME), B31.4 Liquid Transportation Systems for Hydrocarbons. Liquid Petroleum Gas. Anhydrous Ammonia and Alcohols. ASME, New York, NY, 1993. 

Go back to the temperature-mole fraction diagram for the isopropyl alcohol-isobutyl alcohol system (Fig. 140). The composition of the vapor is always different from that of the liquid, and we can separate the two compounds. If the composition of the vapor is the same as that of the liquid, that separation is hopeless. Since we ve used the notions of an ideal gas in deriving... 

The next step is to determine the solubility of the substrate (or its salts) in different solvents. This can also be performed by an automated liquid handling system. Depending upon the solubility of the substrate in water-miscible solvent (alcohols, acetone, tetrahydrofuran, etc.) and water-immiscible solvents (ethyl acetate, methyl-tert-butyl ether, heptane, etc.) the process chemist can identify one or many solvent systems from which the substrate (or its salts) could be ciystallized using the antisolvent addition strategy. 

De Santis, R., Marrelli, L., and Muscetta, P.N. Liquid-liquid equilibria in water-aliphatic alcohol systems in the presence of sodium chloride, Chem. Eng. J., 11 207-214, 1976. 

Alcohols exhibit a bifunctional nature in aqueous solution. On the one hand, there exists a hydrophobic hydrocarbon group which resists aqueous solvation on the other, there is the hydrophilic hydroxyl group which interacts intimately with the water molecules. Franks and Ives (30, 31) have reviewed experimentation and theoretical treatises on the structure of water, the structure of liquid alcohols, and the thermodynamic, spectroscopic, dielectric, and solvent properties and P-V-T relationships of alcohol-water mixtures. Sada et al. (27) reviewed, in particular, the salt effects of electrolytes in alcohol-water systems and discussed the various correlations of the salt effect applied to these systems. Inorganic salts were used almost universally in these salt effect studies. 

The catalytic hydration of olefins can also be performed in a three-phase system solid catalyst, liquid water (with the alcohol formed dissolved in it) and gaseous olefin [258,279,280]. The olefin conversion is raised, in comparison with the vapour phase processes, by the increase in solubility of the product alcohol in the excess of water [258]. For these systems with liquid and vapour phases simultaneously present, the equilibrium composition of both phases can be estimated together with vapour-liquid equilibrium data [281]. For the three-phase systems, ion exchangers, especially, have proved to be very efficient catalysts [260,280]. With higher olefins (2-methylpropene), the reaction was also performed in a two-phase liquid system with an ion exchanger as catalyst [282]. It is evident that the kinetic characteristics differ according to the arrangement (phase conditions), i.e. whether the vapour system, liquid vapour system or two-phase liquid system is used. However, most kinetic and mechanistic studies of olefin hydration were carried out in vapour phase systems. 

Slurry reactors (bubble towers) are fluidized with continuous flow of gas. The particles are smaller (less than 0.1 mm) than in the liquid fluidized systems (0.2-1 mm). In some operations the liquid and solid phases are stationary, but in others they circulate through the vessel. Such equipment has been used in Frscher-Tropsch plants and for hydrogenation of fatty esters to alcohols, furfural to furfuryl alcohol, and of glucose to sorbitol. Hydrogenation of benzene to cyclohexane is done at 50 bar and 220-225°C with Raney nickel of 0.01-0.1 mm dia. The relations between gas velocities, solids... 

The chemical selectivity of reactions catalyzed by supported TEMPO closely resembles the patterns observed for homogeneous reactions. Primary alcohols are strongly preferred over secondary alcohols. Especially in liquid biphasic systems, high aldehyde yields can be achieved with as little as 0.1 mol% of the immobilized catalyst (412) ... 

Gelation. In this step, the polymeric networks link up to form a three-dimensional network throughout the liquid. The system becomes somewhat rigid, characteristic of a gel. The solvent as well as water and alcohol remain inside the pores of the gel. Aggregation of smaller polymeric units to the main network continues progressively on aging the gel. 

This article describes our results on lipase-catalyzed enantio-selective hydrolysis of carboxylic acid esters of two industrially important alcohols related to synthetic pyrethroids in two-liquid phase systems. The two alcohols are 4-hydroxy-3-methyl-2-(2 -propynyl)-2-cyclopentenone (HMPC) and the cyanohydrin, a-cyano-3-phenoxybenzy1 alcohol (CPBA). The configurations, and 2y are given for the liberated stereoisomers of the two alcohols in our lipase-catalyzed reactions. 

Surprisingly, there is limited nonproprietary experimental data on methanol esterification with acetic acid (29). Studies have been confined to liquid-phase systems distant from equilibrium (30), in regions where hydrolysis is unimportant. A physical study of the ternary methanol—methyl acetate—water system is useful for design work (31). Methyl acetate and methanol form an azeotrope which boils at 53.8°C and contains 18.7% alcohol An apparent methanol—water azeotrope exists, boiling at 64.4°C and containing about 2.9% water. These azeotropes seriously complicate methyl acetate recovery. Methyl acetate is quite soluble in water, and very soluble in water—methanol mixtures, hence two liquid phases suitable for decanting are seldom found. 

High Pressure Liquid Chromatography. System HT—k 7.5. UltravioletSpectrum. Dehydrated alcohol—240 nm(Aj =400 a). 

Alternatively, ketyls A may dimerize to pinacol salts E. Isolation of pinacol products F requires further protonation by acids at least as strong as water or ethanol. The notation refers to any of the several possible proton sources, including ammonia, alcohols and the ammonium cation (a strong acid in the liquid ammonia system) (Scheme 6.28). 

Triphase catalyst. Commercial neutral alumina can function as a triphase catalyst in solid-liquid-solid systems. It can catalyze displacement reactions as well as the permanganate oxidation of alcohols. 

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