Showing papers on "Aromatic hydrocarbon published in 1974"

Process for manufacturing and separating from petroleum cuts aromatic hydrocarbons of high purity

Abstract: Process for producing aromatic hydrocarbons, particularly benzene and/or toluene from a feed charge containing saturated and unsaturated hydrocarbons, by catalytic treatment of said charge with hydrogen, fractionation of the resulting product to separate a fraction containing benzene and/or toluene, extractive distillation of at least one aromatic hydrocarbon in a column, by means of an extraction solvent from which said hydrocarbon is subsequently separated, and recycling to the reaction zone of at least one portion of the products recovered at the top of said extractive distillation column and containing essentially C 6 and C 7 saturated hydrocarbons.

Acetylenic polymers, trimers thereof and the production thereof

Abstract: A polymer having one of the general formulae ##EQU1## and ##EQU2## wherein Ar1, Ar2, Ar3, Ar4, Ar5, Ar6, Ar8, Ar9 and Ar10 are the same or different bivalent aromatic hydrocarbon radicals containing six to ten carbon atoms, Ar7 is a trivalent aromatic hydrocarbon radical containing 6 to 10 carbon atoms, and n is 30 to 120.

Aromatic hydrocarbon isomer separation by adsorption

Abstract: The para-isomer from a hydrocarbon feed mixture comprising at least two bi-alkyl substituted aromatic isomers, including the para-isomer, said isomers having from 8 to about 18 carbon atoms per molecule, is separated with a specially prepared solid aluminosilicate adsorbent containing barium and potassium cations or barium cations at the exchangeable sites. The key feature of the adsorbent used in this process is the absence of hydrogen cations or Group II-A cations other than barium at the exchangeable sites thereby permitting faster adsorptiondesorption rates for the desired para isomer.

Separation of tetra-alkyl substituted aromatic hydrocarbon isomers

Abstract: An adsorptive separation process for separating tetra-alkyl substituted monocyclic aromatic isomers, the alkyl constituents containing from one to four carbon atoms each, from a feed mixture comprising at least two of the isomers, which process employs a crystalline aluminosilicate adsorbent containing a specific cation or cations at the exchangeable cationic sites to selectively adsorb a component of the feed mixture. A desorption step may then be used to desorb the adsorbed feed component. The process can be either in the liquid or vapor phase.

Intermolecular interactions in the formation of aromatic hydrocarbon dimers

Abstract: Both short-range and long-range intermolecular interaction energies between two aromatic hydrocarbon molecules, both in their ground state, separated by a range of interplanar distances of 3 ∼ 4 Aring, are estimated using the standard perturbation theory. The results show that aromatic hydrocarbons can form weak sandwich dimers with larger separation between them than is normally believed in their excimers. The non-sandwich form of dimer in which the long in-plane axes of the monomers are parallel and their short in-plane axes inclined, represents an unstable orientation because this form can pass to the perfect sandwich form without an energy barrier.

Process for producing alkylaromatics

Abstract: In a process for producing alkylaromatics by halogenating a paraffin and reacting the halogenated paraffin with an aromatic hydrocarbon, the rate of halogenation is improved by treating the n-paraffin to selectively remove oxygen-containing hydrocarbonaceous compounds from the n-paraffin with a sorbent selective for such oxygen-containing compounds, and subsequently halogenating the treated n-parffin. The improvement is particularly useful in producing alkylaromatic hydrocarbons from monocyclic aromatic compounds and n-paraffins.

Lubricating oil production utilizing hydrogen in two catalytic stages

Abstract: Lubricating oil of increased viscosity index and reduced aromatic hydrocarbon content is prepared by contacting a heavy lubricating oil fraction with hydrogen in the presence of a sulfur-resistant catalyst (e.g., nickel molybdate on alumina) to form an effluent oil and further contacting the effluent oil with hydrogen in the presence of a hydrogen- or rare-earth-exchanged, faujasite catalyst containing a platinum group metal to produce a product from which a lubricating oil having a reduced aromatic hydrocarbon content relative to the feedstock can be recovered.

Preparation of phenyl methyl carbinol

Abstract: OF THE DISCLOSURE Phenyl methyl carbinol is prepared from aceto-phenone by hydrogenation over a fixed bed of copper con-taining catalyst in the presence of a molar excess of hydrogen at 0.2-10 WHSV at 90-150°C., improved conversion, selectivity and/or yield being achieved by reason of the acetophenone being dissolved in 20-80 per cent monouclear aromatic hydrocarbon of the group consisting of benzene, ethyl benzene, and toluene.

Dehydrogenation of alkyl aromatic hydrocarbons

Abstract: Self-regenerative dehydrogenation catalysts for converting alkyl aromatic hydrocarbons having at least 2 C atoms in at least one alkyl group are activated by short interrupted alkyl aromatic hydrocarbon feed cycles and continued steam feeding. After each such interrupted feed cycle conversion of alkyl aromatic hydrocarbons to the corresponding alkenyl aromatic derivative is increased, selectivity remains high and operations can be carried out under high severity conditions. In addition, a higher average activity level is attained and selectivity depression is eliminated or minimized.

Process for the acylation of aromatic hydrocarbons

Abstract: Acylation of aromatic hydrocarbons which comprises reacting said aromatic hydrocarbon with an acyl halide and a saturated hydrocarbon which contains at least one tertiary carbon atom, or which is isomerized to form a saturated hydrocarbon containing a tertiary carbon atom, in the presence of a Friedel-Crafts catalyst is disclosed.

Spectroscopic studies of orientational interactions between straight-chain alkanes and aromatic hydrocarbons

Abstract: Spectral shift measurements of u.v. absorption spectra of aromatic hydrocarbon soluted in alkane solvents show that the shift is systematically larger in normal alkanes that in the corresponding branched isomers. This result is related to the short range order existing preferentially in n-alkane liquids and is interpreted as a mutual orientation between solute and solvent molecules, resulting in maximum interaction. These oriented interactions are confirmed by theoretical calculations and an interesting correlation is made with the specific adsorption of n-alkanes on the graphite basal planes. Absorption and emission spectra of aromatic hydrocarbon doped n-heptane single crystals, exhibit a strong dichroic effect, again showing a high degree of orientation of the solute molecules in the lattice.

Process for producing uninhibited transformer oil

Abstract: A method for producing uninhibited transformer oil is disclosed which includes isolating a petroleum distillate that is primarily naphthenic and aromatic in character, boiling above 400°F, having a viscosity between 50 and 100 SSU at 100°F, and containing sulfur compounds; contacting the distillate with a solvent selective for aromatic hydrocarbons under conditions to produce a raffinate phase containing 15-30%v aromatic hydrocarbons; hydrotreating the raffinate phase to reduce the nitrogen content to at most 25 PPM, to maintain the sulfur content greater than 0.08%w, and to maintain the aromatic hydrocarbon content greater than 15%v. The product is an uninhibited transformer oil, and it can be further improved by regenerative clay treatment and by the addition of certain aromatic hydrocarbon compounds containing two or more six carbon membered fused or unfused rings, at least one of which is a benzene ring.

N,N'-substituted 2,4,5-triketoimidazolidines

Abstract: A process for the preparation of modified N,N'-substituted-2,4,5-triketoimidazolidines which comprises reacting a precondensate having terminal isocyanate groups, prepared by reacting (a) a polybasic carboxylic acid, containing from 4 to 70 carbon atoms and from 2 to 6 carboxyl groups, with an excess of (b) one or more isocyanates or isocyanate forming compounds in the presence of a solvent, with (c) at least one oxamidic ester containing the group NH--CO--CO--OR v wherein R v represents an aliphatic hydrocarbon group containing up to 18 carbon atoms, a cycloaliphatic hydrocarbon group containing up to 8 carbon atoms or a mononuclear aromatic hydrocarbon group being unsubstituted or substituted by at least one hydrocarbon group and having a total of up to 14 carbon atoms in the presence of a solvent, a product prepared by said process and a shaped article comprising such a product.

Process for the production of high purity alkali metal tetrahaloaluminates and products produced thereby

Abstract: A process is described for the production of sodium, potassium or lithium tetrahaloaluminates, in which the halogen may be chlorine, bromine or iodine, by the reaction of an aluminum halide with at least the stoichiometric amount of an alkali metal halide in the presence of powdered aluminum metal and a stable liquid hydrocarbon solvent, preferably an aromatic hydrocarbon solvent or mixtures of aromatic and saturated hydrocarbon solvents, at a temperature in the range from about 60° C. up to the reflux temperature of the reaction mixture, filtering the hot reaction mixture to remove remaining aluminum metal and other solids, cooling the filtrate to below about 30° C., and separating and washing the resulting crystals to obtain the substantially pure alkali metal tetrahaloaluminate; the entire process being carried out under anhydrous conditions and an inert atmosphere.

Preparation of alkali metal hydrides

Abstract: This invention relates to the preparation of alkali metal hydrides and of alkali metal aluminum dihydrocarbon dihydrides and in particular to such compounds of sodium, potassium or lithium having in the case of the dihydrocarbon compounds hydrocarbon radicals containing from 2 to about 30 carbon atoms per radical. Such dihydrocarbon materials, as typified by sodium aluminum diethyl dihydride, and by the potassium or lithium counterparts, either singly or in mixtures with respect to alkali metals and hydrocarbon groups, are soluble and useful in inert aromatic hydrocarbon solutions and have excellent mild reducing properties for various functional groups such as carbonyl groups in various organic compounds. The alkali metal hydrides are useful in many known ways such as in condensation and alkylation reactions and as chemical intermediates such as in the preparation of the alkali metal aluminum dihydrocarbon dihydrides.

Water washing method for borate removal in an aromatic alkylation process

Abstract: A method of water washing an aromatic recycle stream to remove boron oxide hydrates formed in a boron halide promoted aromatic hydrocarbon alkylation process comprises admixing water with the recycle stream and passing this mixture into the overhead receiver system of the aromatic feed stream drying column Alternatively the aromatic recycle stream may be charged directly to the overhead receiver The hydrates enter the aromatic recycle stream as a volatile complex formed by charging a boron halide to the reactor effluent distillation column

Investigation of Oils in the Western Canada Tar Belt

Abstract: In this investigation the hydrocarbons and sulphur compounds in the gas oils of the Athabasca, Cold Lake and Lloyd-minster heavy oils have been studied by a combination of liquid, gas-liquid and gas-solid chromatographic techniques coupled with mass spectrometry. The results were compared with those for the Medicine River oil which is lighter, thermally mature and lies in a reservoir of the same geological age. The distillates were fractionated into hydrocarbon types (i.e., saturates, mononuclear, dinuclear and polynuclear aromatics). This allowed a comparative study of the normal alkanes and isoprenoid hydrocarbons, pristane and phytane, in the C16 to C19 range of the saturates. Also the structural changes in the aromatic hydrocarbon types, as indicated by both gas chromatography coupled with mass spectometry, have been followed up. The results were interpreted geochemically with reference to the thermal and biological aspects of degradation. It is quite clear that these oils are closely related although there are some distinct differences. The number of isomers of the sulphur compounds appears to be low in comparison with the number of possible isomers, suggesting some selective mechanism of formation.

Deuterium effect on the quenching of aromatic hydrocarbon triplet excited states by oxygen

Abstract: By using ultraviolet light flash excitation, the triplet (phosphorescence) decay time τ of a series of protonated (p) and deuterated (d) aromatic hydrocarbons dissolved in a fluffy freeze‐dried polystyrene matrix was studied as a function of oxygen pressure [O2] at 298°K. The quenching constants γ were calculated from linear plots of τ−1 as a function of [O2] and the ratios of γ(p)/γ(d) are 1.2±0.1 for anthracene and 1,2‐benzanthracene, 1.9±0.2 for pyrene, 1.4±0.2 for chrysene, and 2.5±0.4 for naphthalene. These results are interpreted in terms of Franck‐Condon factors and the energy transfer quenching model proposed by Kawaoka, Khan, and Kearns in which the 1Δg and 1Σg+ excited states of oxygen are generated, and in which the remaining energy is dissipated by the vibrational modes of the quenched aromatic molecules. In pyrene and in naphtalene, the 1Δg pathway appears to be more important than in chrysene and dominates over the 1Σg+ mechanism. No conclusions can be reached about the preferred mode of ene...

Aqueous aerosol air drying paints

Abstract: An aerosol paint composition is provided which is composed of a dispersion of an alkyd or polyester resin, containing a pigment, in a liquid medium. The liquid medium has two components the first of which is a mixture of 30 to 50 percent of an aromatic hydrocarbon and 50 to 70 percent of a halogenated hydrocarbon, the mixture having a boiling point between 70° - 150°C, and, the second of which is a liquified normally gaseous halogenated hydrocarbon having 1 to 4 carbon atoms and a boiling point below about 25°C.

Process for the manufacture of cyclohexene dicarboxylic acid esters

Abstract: The hydrogenation of benzene dicarboxylic acid mono and diesters to corresponding cyclohexene dicarboxylic acid mono and diesters by carrying out the hydrogenation in the active and effective presence of alkalimetal amalgam and an alcohol in a substantially anhydrous environment. The hydrogenation reaction medium should be a mixture of the above referred to alcohol and an aromatic hydrocarbon such as toluene.