Ethyl-acetate-ethanol-water mixture

The extracted crude luciferin was purified by Anderson s benzoy-lation method mentioned above (Anderson, 1935), followed by partition chromatography on a cellulose powder column using a mixture of ethyl acetate-ethanol-water (5 2 3 Tsuji, 1955) as the solvent, again in a hydrogen atmosphere. The luciferin obtained (3 mg) was highly pure by paper chromatography, and appeared suitable for crystallization. I... 

Chemically modified alkylamine columns are the most widely used stationary phase for saccharide separations and are generally eluted with mobile phases consisting of acetonitrile-water mixtures. This mixture has been found to be far superior to others such as methanol-water (Rabel et al., 1976) and ethyl acetate-ethanol-water (Binder, 1980). It has been observed that as the water content of the mobile phase is increased the retention of saccharides is decreased. The columns are usually stable for periods of up to 3 months but... 

Fig. 29. Chromatogram of polyhydric alcohols in ethyl acetate-ethanol-water (12 2 1) (1) Glucose, (2) D-arabitol, (3) 2,3-butylene glycol, (4) mixture of glycerol, ethylene glycol, and 1,2-propylene glycol, (5) 1,2-propylene glycol, (6) ethylene glycol, (7) glycerol.

Extractive distillation can be generally used to separate close boiling liquids or azeotropes, which cannot be separated through conventional distillation process. A solvent is introduced into the distillation column to alter the relative volatility of the feed components, and to avoid the formation of azeotropes. The extracted less volatile components leave from the bottom, whereas more volatile components come out as top products in pure form. Extractive distillation can replace conventional distillation or extraction processes resulting in improved separations, reduced capital investment and energy consumption. Industrially, extractive distillation can be implemented for binary separations resolving the close boiling mixtures, namely m-xylene/ o-xylene, methyl-cyclohexane/toluene, propylene/propane, 1-butane/1,3-butadiene, and azeotropic mixtures such as iso propylether/acetone, ethyl acetate/ethanol/water, MTBE/ethanol, etc. 

Currently, the most successful methodology for the optimization of an SMB s performance is the so-called triangle theory, which was recently also applied to the SMBR [158]. The analysis was based on a mathematical model describing the esterification of acetic acid and ethanol into ethyl acetate and water in a fixed-bed chromatographic reactor [159]. A mixture of ethanol and acetic acid is intro-... 

The catalytic esterification of ethanol and acetic acid to ethyl acetate and water has been taken as a representative example to emphasize the potential advantages of the application of membrane technology compared with conventional distillation [48], see Fig. 13.6. From the McCabe-Thiele diagram for the separation of ethanol-water mixtures it follows that pervaporation can reach high water selectivities at the azeotropic point in contrast to the distillation process. Considering the economic evaluation of membrane-assisted esterifications compared with the conventional distillation technique, a decrease of 75% in energy input and 50% lower investment and operation costs can be calculated. The characteristics of the membrane and the module design mainly determine the investment costs of membrane processes, whereas the operational costs are influenced by the hfetime of the membranes. 

The kinetics of the reaction between bromopropionate and thiosulfate ions have been studied at 10-40 °C in various ethanol-water mixtures.107 Activation parameters were evaluated as a function of ionic strength and dielectric constant of the medium. The medium effect of mixed solvents on the rate constants of the Menshutkin reaction of triethylamine with ethyl iodide has been studied for binary mixtures of cyclohexane with benzene or ethyl acetate,108 and with chlorobenzene or dimethoxyethane.109 Rates were measured over the temperature range 293.1-353.1 K, and activation parameters were determined. 

Many different solvent developers have been used in the separation of sugars and related compounds. Three of these, phenol-water, collidine-water, and 1-butanol-acetic acid-water,27 also commonly employed in the resolution of amino acid mixtures, are widely used. Other commonly used solvent developers are 1-butanol-ammonia-water, 1-butanol-ethanol-water,27 1-butanol-pyridine-water,61 ethyl acetate-acetic acid-water, and ethyl acetate-pyridine-water.26... 

A solution of (R)-5-trans-(2-phenylsulfonylethenyl)-3-(N-methylpyrrolidin-2-ylmethyl)-lH-indole and 10% Pd/C in ethanolic hydrogen chloride (prepared from absolute ethanol and acetyl chloride and N,N-dimethylformamide was shaken under a hydrogen atmosphere at room temperature). The resultant reaction mixture was filtered through diatomaceous earth (Celite trademark), washed with absolute ethanol, and the combined filtrates were evaporated under reduced pressure. The residue was partitioned between ethyl acetate and water. The organic phase was separated, washed with water, brine, dried... 

Methyl-l-piperazinyl)benzimididazole (5.00 g) prepared as above is dissolved in N,N-dimethylformamide (50 ml) and thereto is added sodium hydride (concentration 50%) (1.50 g) at room temperature, and the mixture is stirred for 30 minutes. To the mixture is added 2-bromoethyl ethyl ether (4.00 g), and the mixture is stirred at 70°C for 10 hours. To the reaction mixture is added water (150 ml), and the mixture is extracted with ethyl acetate. The extract is washed with water, dried over anhydrous magnesium sulfate and then concentrated to give a brown oily substance (5.40 g). The brown oily substance is treated with fumaric acid (3.26 g) in hot ethanol. The crude crystals thus obtained are recrystallized from ethyl acetate-ethanol to give l-[2-(ethoxy)ethyl]-2-(4-methyl-l-piperazinyl)benzimidazole 3/2 fumarate (6.31 g) as colorless plates, melting point 167.5°-168.5°C. Elementary analysis for C22H30N4O7 Calcd. (%) C, 57.13 H, 6.54 N, 12.11 Found (%) C, 57.04 H, 6.44 N, 12.02. 

Triphenyl Tellurium Cyanide1 20 g of a Baker CHA-541 resin are treated with aqueous sodium cyanide solution, the column is washed with ethanol/water mixtures with increasing ethanol content, and, finally, the column is covered with 95% ethanol. A solution of 0.1 g (2.5 mmol) of triphenyl telluronium chloride in 60 ml of 95% ethanol is slowly passed through the column. The column is eluted with 200 ml of ethanol, the cluate is evaporated, the oily residue is triturated with ethyl acetate, and the crystals are collected, washed with ethyl acetate, and dried under vacuum yield 0.82 g (85%) m.p. 184° (dec.). 

Fischer esterification is an equilibrium, and typical equilibrium constants for esterification are not very large. For example, if 1 mole of acetic acid is mixed with 1 mole of ethanol, the equilibrium mixture contains 0.65 mole each of ethyl acetate and water and 0.35 mole each of acetic acid and ethanol. Esterification using secondary and tertiary alcohols gives even smaller equilibrium constants. 

The purity of the sample in acetone - water mixture ( 93 7 ) and in ethyl acetate - ethanol mixture (1 1) was found to be... 

Before the advent of commercially available methods, it was common to use two-phase, liquid-liquid partition with organic solvents and solvent mixtures, including methylene chloride, hexane, diethyl ether, ethanoi/chloroform/water, methylene chloride/methanol, hexane/isopropanoi, and cydohexane/ethyl acetate. Ethanol and methanol... 

Comparison with experimental data shows that the complete local-composition equation preserves the quality of Wilson s equation in describing vapor-liquid equilibrium of completely miscible systems. There are no more than slight differences between the complete equation and Wilson s equation in the fitting of data. But the complete local-composition (CLC) equation extends Wilson s local-composition equation to partially miscible solutions. Good predictions of the coexistent liquid compositions of ternary mixtures based on the binary parameters have been found for water + ethyl acetate + ethanol, for water + methyl acetate + acetone, and for water + acrylonitrile + acetonitrile. 

Pouring. Many workers prefer not to use mechanical spreading methods at all. If the adsorbent is very finely divided and of homogeneous particle size, and if no binder is used, a slurry can be poured on a plate and allowed to flow over it so that it is evenly covered. Some manual dexterity is required to do this properly. Preparation of plates by pouring is particularly easy with certain types of alumina, but water alone is not usually suitable for making the slurry a volatile liquid such as ethanol (or an ethanol-water mixture) or ethyl acetate is preferable. The appropriate amounts of liquid and solid adsorbent needed to cover a plate have to be found by trial and error, and exactly those quantities should... 

We consider esterification of ethanol with acetic acid to form ethyl acetate and water. This reaction has been much used for testing algorithms that perform simultaneous phase and reaction-equilibrium calculations. At ambient pressures, we assume the reaction occurs in a vapor phase but depending on the exact values for T and P, the mixture may exist as one-phase vapor, one-phase liquid, or a two-phase vapor-hquid system. The feed contains equimolar amounts of ethanol and acetic acid. The problem is to determine the equilibrium state the phases present and their compositions at 1.0133 bar and temperatures near 355 K. 

What boiling points can do is to indicate the order in which the components of a mixture will evaporate. Thus, a mixture of ethyl acetate, ethanol and water will boil off in the order ... 

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