Showing papers on "Hexane published in 1975"

Multiple solvent heavy oil recovery method

Abstract: Petroleum may be recovered from viscous petroleum-containing formations including tar sand deposits by injecting into the formation a multiple-component solvent for the petroleum. At least one solvent component is gaseous at the temperature and pressure of the petroleum reservoir such as carbon dioxide, methane, ethane, propane, butane or pentane and at least one component is liquid at the reservoir conditions, such as hexane and higher molecular weight aliphatic or aromatic hydrocarbons. The multiple solvent is preferably introduced under sufficient pressure that it is substantially all in the liquid phase. Recovery of petroleum and solvent may be from the same well as is used for injection or from a remotely located well. When the pressure in a portion of the formation contacted by the solvents is reduced below the vapor pressure of the gaseous solvent, it vaporizes to provide drive energy for oil production. The liquid components dissolve in the petroleum and reduce the petroleum viscosity.

Compartmentalization of amino acids in surfactant aggregates - Partitioning between water and aqueous micellar sodium dodecanoate and between hexane and dodecylammonium propionate trapped water in hexane

Abstract: Cationic amino acids, arginine and lysine partition differentially from water into aqueous micellar sodium dodecanoate. Conversely, partitioning of serine, glycine, aspartic acid, glutamic acid, threonine, alanine, proline, valine, leucine, phenylalanine and isoleucine do not vary appreciably. Partitioning from neat hexane into dodecylammonium propionate trapped water in hexane is, however, dependent upon both electrostatic and hydrophobic interactions. These results imply that the interior of dodecylammonium propionate aggregates is negatively charged and is capable of hydrogen bonding in addition to providing a hydrophobic environment. The solubilities of amino acids in neat hexane substantiate the previously derived amino acid hydrophobicity scale. Relevance of partitioning in these systems to the postulated selective amino acid compartmentalization is discussed.

Viscosity and charge carrier mobility in the saturated hydrocarbons

Abstract: An equation showing the dependence of the viscosity of saturated hydrocarbon liquids on the number of carbon atoms in the molecule is proposed, and the degree to which it is in agreement with experimental results is examined. A further equation, showing the relationship between viscosity and boiling point, is derived. Finally an expression showing the dependence of ionic mobility on the number of carbon atoms in the molecule is presented, and it is shown that a similar expression may apply for electronic mobility in pentane and hexane.

The activation of saturated hydrocarbons by transition-metal complexes in solution. Part IV. Oxidation of benzene and of alkanes by hexachloroplatinate(IV)

Abstract: Benzene is oxidised to chiorobenzene by H2PtCl6 in aqueous trifluoroacetic acid at 120 °C. The initial formation of a water-soluble complex of platinum(IV) and benzene is accelerated by an increase in the H2PtCl6 concentration and by addition of K2[PtCl4], and is reduced by the addition of chloride ion. Subsequent reactions give chlorobenzene; some of it complexes with platinum. An analogous study has been made of the oxidation of alkanes, particularly hexane, using the same system. Evidence for the formation of chlorohexanes from hexane and of platinum complexes with hydrocarbon ligands has been obtained. 2- and 3-chlorohexanes are further oxidised and, from determinations of the amount of PtIV reduced during the reaction, it appears likely that polychlorinated carboxylic acids are formed. The mechanisms of aromatic and alkane oxidation in this system are initially very similar. The reaction of cyclohexane with H2PtCl6 is more complex. In addition to chlorination, dehydrogenation occurs to give benzene and chlorobenzene.

Rapid quantitative determination of residual hexane in oils by direct gas chromatography

Abstract: A simple, direct, gas chromatographic technique is described for the quantitative determination of residual hexane in extracted vegetable oils The method if rapid and sensitive to one ppm hexane The inlet liner of a gas chromatograph was packed with 1 1/2 in glass wool, and 25 mg oil was added onto it The sample was capped with a small plug of glass wool, and the liner was inserted in the heated inlet of the gas chromatograph Residual hexane rapidly eluted onto the Poropak P column by heat, and carrier gas was resolved in 20 min by temperature programing between 70–180 C The method appears useful for monitoring continuous solvent removal processes

The Effect of Pressure and Temperature on the Toluene-Iodine Charge Transfer Complex inn-Hexane

Abstract: ABSTRACT. The effect of pressure and temperature on the stabilities of the benzene-iodine charge transfer complex have been investigated through ultraviolet spectrophotometric measureme­ nts in n-hexane. The stabilities of the complexes were measured at temperatures of 25, 40 and 60°C up to 1600 bars. The equilibrium constant of the complex formation was increased with pre­ ssure and decreased with temperature raising. The absorption coefficient was increased with both pressure and temperature. Changes of volume, enthalpy, free energy and entropy for the forma­ tion of complexes were obtained from the equilibrium constants. The red-shift at a higher pressure, 나ic blue-shift at a higher temperature and the relation between pressure and oscillator stre­ ngth were' discussed by means of thermodynamic functions.

Fate of Dichlorvos Residues During Milling and Oil Extraction of Soybeans

Abstract: One week after stored soybeans were treated with 20 ppm dichlorvos in a water emulsion, all milling and processing fractions contained residues though less than 1 ppm was present on the whole beans. Steaming did not remove residues from the dehulled meats, crude oil, or meal. Residues from the flakes passed into the miscella (extracted oil in hexane) and extracted marc (flakes with oil removed by extraction) and were subsequently detected in the crude oil and crude meal and in the hexane from both of these fractions. The residues could be removed from the hulls and crude meal by toasting and from the crude oil by refining.

The radical stabilization energy due to an a-chlorine atom from the kinetics of the thermal isomerization of 1-Chlorobicyclo[2,2,0]hexane in the gas and liquid phase

Abstract: The rate of isomerization of 1-chlorobicyclo[2,2,0]hexane to 2- chlorohexa-1,5-diene, both in the gas phage and in solution, has been measured over the temperature range 409-497 K. The Arrhenius parameters derived from these rates are represented by the equations log(kg/s-1)=(13.49±0.08)-(148.2±0.6/θ log(ka/s-1)=(13.21±0.12)-(144.44±0.50)/θ and log(kb/s-1)=(13.25±0.44)-(144.8±1.6)/θ where the subscripts g, a and b refer to the gas phase, tetrachloroethylene as solvent and o-dichloro-benzene as solvent respectively, θ = 19.15 kJ mol-1 and the errors are least-squares deviations. A radical stabilization energy of 5±2 kJ mol-1 for the α- chlorine atom derived from these Arrhenius parameters is in excellent agreement with the value derived from kinetics of the isomerization of 1,4-dichlorobicyclo[2,2,0]hexane and from the thermochemistry of chloroethyl radicals.

Identification of the Volatile Constituents of the Egyptian Lemongrass Oil. Part II. Thin Layer Chromatography

Abstract: The chemical components of the Egyptian Lemongrass oil were analysed. The oil gained by steam distillation of the vegetative organs of the plant. Thin-layer chromatography of Lemongrass oil was tried with two solvent systems, i. e. cyclohexane: ethylacetate with 85:15, and hexane: ethylacetate with 90:10 V/V. The following results were obtained: The constituents of this oil were eight components. The oil sample proved that the citral component was detected in Egyptian Lemongrass oil with 0.64 Rf value. The oil obtained also geraniol, linalool and their esters. The nerol, cineal and citronellal were also detected.

Permanganate Oxidation of the Hexane and Ether Extracts of Raw Humus

Abstract: Methylated and unmethylated hexane and ether extracts of raw humus were oxidized by potassium permanganate at pH 9–10. Methylated ether extract gave 6 benzenecarboxylic acid methyl esters, 6 methoxy-benzenecarboxylic acid methyl esters, 3,4-dimethoxy-benzoic acid methyl ester, and 6 dicarboxylic acid dimethyl esters among other products. No methoxy or dimethoxy derivatives were found after oxidation of unmethylated hexane or ether extracts or methylated hexane extract. These extracts gave benzenecarboxylic acid methyl esters and dicarboxylic acid dimethyl esters. All extracts yielded fatty acids; the hexane extract was found to contain 17 percent and the ether extract 11 percent of straight chain fatty acids, free or esterified. For both extracts the molar distribution of the acids, C12-C33, was approximately the same, with C24 and C22 dominating. Both extracts yielded significant amounts of 1(a),3(a)-dimethylcyclohexane-1(e),2(e),3(e)-tricarboxylic acid trimethyl ester by oxidation. 1(a),3(a)-Dimethyl-2(e)-carbomethoxymethyl-cyclohexane-1(e),3(e)-dicarboxylic acid dimethyl ester was also found from the ether extract. A number of the compounds isolated have also been found after oxidation of other humic fractions, thus indicating a certain similarity in composition between especially the ether extract and these fractions. Compared to the other humic fractions the ether extract, and even more the hexane extract, yields a significantly higher amount of aliphatic structures. It is concluded that the resinous part of the ether extract contains little and the hexane extract none of the condensed phenolic structures usually present in soil organic matter. Both extracts contain cyclic aliphatic systems, probably of the abietic acid type or transformation products of this type of compound. The results indicate that both extracts also contain aromatic rings substituted or linked together by aliphatic chains of the length 6–8 CH2 units.

Conformational analysis of 2-phenyl-1,3-diazabicyclo[3.1.0]hexane

Abstract: The 2-phenyl-1,3-diazabicyclo[3.1.0]hexane molecule was subjected to conformational analysis within the framework of the Westheimer method. The optimum conformations of two of its possible stereoisomers (endo and exo) were found, and the equilibrium concentrations of the latter were calculated and found to be 62 and 38%, respectively. The results of the calculations are in good agreement with the PMR spectroscopic data.

Rearrangement of carane system to 1-methyl-4-isopropylbicyclo[3.1.0]hexane system

Abstract: The acetolysis of the monotosylates of the 3β,4α- and 3β,4β-caranediols proceeds with rearrangement of the carane system to the 1-methyl-4-isopropylbicyclo[310]hexane system The second epimer of 1-methyl-4-(α-hydroxyisopropyl)bicyclo[310]-2-hexanol was obtained for the first time