Water-hydrocarbon mixtures

Hquid—Hquid-phase spHt the compositions of these two feed streams He oa either side of the azeotrope. Therefore, column 1 produces pure A as a bottoms product and the azeotrope as distillate, whereas column 2 produces pure B as a bottoms product and the azeotrope as distillate. The two distillate streams are fed to the decanter along with the process feed to give an overall decanter composition partway between the azeotropic composition and the process feed composition according to the lever rule. This arrangement is weU suited to purifying water—hydrocarbon mixtures, such as a C —C q hydrocarbon, benzene, toluene, xylene, etc water—alcohol mixtures, such as butanol, pentanol, etc as weU as other immiscible systems. 

The experimentally fitted hydrate guest Kihara parameters in the cavity potential uj (r) of Equation 5.25 are not the same as those found from second virial coefficients or viscosity data for several reasons, two of which are listed here. First, the Kihara potential itself does not adequately fit pure water virials over a wide range of temperature and pressure, and thus will not be adequate for water-hydrocarbon mixtures. Second, with the spherical Lennard-Jones-Devonshire theory the point-wise potential of water molecules is smeared to yield an averaged spherical shell potential, which causes the water parameters to become indistinct. As a result, the Kihara parameters for the guest within the cavity are fitted to hydrate formation properties for each component. 

McAuliff [15] reported that the sampling errors caused in the injection of water-hydrocarbon mixture on to a gas chromatographic column can be overcome by the addition of acetone for solubilisation only when the hydrocarbon chain length is less than 12. The emulsified sample is injected directly on to a column 1.2mx6mm of 10% of SE-30 on Chromosorb W HMDS (80-100 mesh) operated at 170-210°C, with hydrogen flame ionisation detection. Results are given for the hydrocarbons from Cn to Ci8. 

In general, Ru-based catalysts are more efficient than Rh-based catalysts for the selective hydrogenation of BT to DHBT in water/hydrocarbon mixtures [19]. Rhodium forms much better catalysts for the hydrogenolysis of thiophenes to thiols (vide infra). 

Economou, LG. and Tsonopoulos, C., Associating models and mixing rules in equations of state for water/hydrocarbon mixtures, Chem. Eng. Set, 52(4), 511-525, 1997. 

The gases are quenched at the furnace exit by water or a water,hydrocarbon mixture, rid of tars (Cottrell electrostatic precipitator) and compressed before being sent rt> the... 

Water/hydrocarbon mixture Condensation, separation of the liquid water/ben-zine. The waste gas is ignited and the wastewater is fed to a treatment plant, e) Recovery of methanol and toluene [115]. During the production of a textile chemical a solution (mother liquor) is produced containing methanol and an aromatic solvent (toluene or xylene). An azeotrope containing methanol and toluene is produced by discontinuous ditillation. The toluene-containing phase separates out on addition of water. Methanol is recovered from the methanol-containing phase by continuous... 

Franck equations of state for water + hydrocarbon mixtures... 

The success of this equation was shown from the start (Fowkes, 1964) as it was illustrated that experimental liquid-liquid interfacial tension data for ten mercury-hydrocarbon mixtures and for eight water-hydrocarbon mixtures resulted to more or less unique values for the dispersion contribution of mercury and water, respectively (see Example 3.3). Moreover, these values are in agreement with those estimated from theoretical considerations. 

The principal nonpolar-type adsorbent is activated carbon. Kquilihrium data have been reported on hydrocarbon systems, various organic compounds in water, and mixtures of organic compounds (11,15,16,46,47). With some exceptions, the least polar component of a mixture is selectively adsorbed eg, paraffins are adsorbed selectively relative to olefins of the same carbon number, but dicycUc aromatics are adsorbed selectively relative to monocyclic aromatics of the same carbon number (see Carbon, activated carbon). 

Physical properties of glycerol are shown in Table 1. Glycerol is completely soluble in water and alcohol, slightly soluble in diethyl ether, ethyl acetate, and dioxane, and insoluble in hydrocarbons (1). Glycerol is seldom seen in the crystallised state because of its tendency to supercool and its pronounced freesing point depression when mixed with water. A mixture of 66.7% glycerol, 33.3% water forms a eutectic mixture with a freesing point of —46.5°C. 

When comparable amounts of oil and water are mixed with surfactant a bicontinuous, isotropic phase is formed [6]. This bicontinuous phase, called a microemulsion, can coexist with oil- and water-rich phases [7,1]. The range of order in microemulsions is comparable to the typical length of the structure (domain size). When the strength of the surfactant (a length of the hydrocarbon chain, or a size of the polar head) and/or its concentration are large enough, the microemulsion undergoes a transition to ordered phases. One of them is the lamellar phase with a periodic stack of internal surfaces parallel to each other. In binary water-surfactant mixtures, or in... 

A quick estimate of the overall column efficiency can be obtained from the correlation given by O Connell (1946), which is shown in Figure 11.13. The overall column efficiency is correlated with the product of the relative volatility of the light key component (relative to the heavy key) and the molar average viscosity of the feed, estimated at the average column temperature. The correlation was based mainly on data obtained with hydrocarbon systems, but includes some values for chlorinated solvents and water-alcohol mixtures. It has been found to give reliable estimates of the overall column efficiency for hydrocarbon systems and can be used to make an approximate estimate of the efficiency for other systems. The method takes no account of the plate design parameters and includes only two physical property variables. 

Burris, D.R., MacIntyre, W.G. (1986) A thermodynamic study of solutions of liquid hydrocarbon mixtures in water. Geochim. Cosmochim. Acta 50, 1545-1549. 

Mofex A liquid-liquid extraction process for removing aromatic hydrocarbons from hydrocarbon mixtures. The solvent is a monomethylformamide/water mixture, operated at 20 to 30°C, 0.1 to 0.4 bar. Developed by Leuna-Werke. 

---