Showing papers on "Aromatic hydrocarbon published in 1981"

Embryotoxic effects of benzo[a]pyrene, chrysene, and 7,12-dimethylbenz[a]anthracene in petroleum hydrocarbon mixtures in mallard ducks.

Abstract: Studies with different avian species have revealed that surface applications of microiiter amounts of some crude and fuel oils that coat less than 10% of the egg surface result in considerable reduction in hatching with teratogenicity and stunted growth. Other studies have shown that the embryotoxicity is dependent on the aromatic hydrocarbon content, further suggesting that the toxicity is due to causes other than asphyxia. In the present study the effects of three polycyclic aromatic hydrocarbons identified in petroleum were examined on mallard (Anas platyrhynchos) embryo development. Addition of benzo[a]‐pyrene (BaP), chrysene, or 7,12‐dimethylbenz[a]anthracene (DMBA) to a synthetic petroleum hydrocarbon mixture of known composition and relatively low embryotoxicity resulted in embryotoxicity that was enhanced or equal to that of crude oil when 10 μl was applied externally to eggs at 72 h of development. The order of ability to enhance embryotoxicity was DMBA > BaP > chrysene. The temporal pattern of e...

Method for removing polyhalogenated hydrocarbons from nonpolar organic solvent solutions

Abstract: A method is provided for reducing the level of polychlorinated aromatic hydrocarbons, "PCB's", while dissolved in an organic solvent, for example, transformer oil. Removal of the polychlorinated aromatic hydrocarbon, can be accomplished by treating the contaminated solution with a mixture of polyethyleneglycol and an alkali metal hydroxide.

Identification of Ozonation Products of Aromatic Hydrocarbon Micropollutants: Effect on Chlorination and Biological Filtration

Abstract: A study was made of the identification of substances produced by the ozonation of some aromatic compounds in a dilute aqueous medium: the aim was to determine the influence of ozonation on post–chlorination as well as on the mechanism of elimination of organic matter in secondary filtration on activated carbon. The nature of ozonation products such as aldehyde ketone and acid accounts for the following results –a change in chlorine demand and trihalomethane production –a loss in physical adsorption on activated carbon –the significance of biodegradation in secondary filtration on activated carbon

Adsorption of benzene and toluene on Y zeolites studied by infrared spectroscopy

Abstract: The adsorption of benzene and toluene molecules on NaY, NaHY, dehydroxylated zeolites and NaHY zeolite containing preadsorbed pyridine was studied by i.r. spectroscopy. The frequencies of the i.r. bands of adsorbed benzene and toluene are similar to those found for dissolved hydrocarbons, although the intensity of some bands is several times lower than in dissolved hydrocarbons, indicating that the adsorption of aromatic hydrocarbon molecules in the zeolite cavities results in a certain distortion of the electron cloud of the molecule. The first molecules of benzene or toluene to be adsorbed are bonded to Na+ ions, the next adsorbed molecules forming hydrogen bonds with the OH groups vibrating at 3640 cm–1. The frequency shift of the i.r. band of the OH groups may be taken as a measure of their acid strength. The acid strength of high-frequency OH groups decreases with the amount of pyridine adsorbed.

Avoidance Reactions of Juvenile Coho Salmon (Oncorhynchus kisutch) to Monocyclic Aromatics

Abstract: Presmolt coho salmon (Oncorhynchus kisutch) tested in a Y-maze avoided a mixture of monocyclic aromatic hydrocarbons at concentrations of 3–4 mg/L while smolting coho salmon avoided concentrations of less than 2 mg/L. Three components (benzene, toluene, o-xylene) of the mixture were tested individually with presmolt salmon and each was avoided at a lower concentration than when compared with the total hydrocarbon concentration of the mixture; o-xylene was most repellent, causing statistically significant avoidance at a concentration of 0.2 mg/L. Electrophysiological recordings from the olfactory bulb indicated that short-term exposure of juvenile coho salmon to monocyclic aromatic hydrocarbons at 4 mg/L did not disrupt this chemosensory modality; the olfactory system was stimulated by an aromatic hydrocarbon mixture at concentrations correlating with observed avoidance behavior.Key words: salmon, behavior, avoidance, monocyclic aromatic hydrocarbons, Oncorhynchus, olfactory EEG

Enhanced oil recovery

Abstract: The recovery of residual oil which is found in subterranean reservoirs may be accomplished by utilizing an aqueous surfactant slug to reduce the interfacial tension between oil and water. An effective surfactant slug which may be used will comprise a mixture of: (1) from about 1 to about 10% of a sulfonate of a mixture of mono- and dialkyl-substituted aromatic hydrocarbon which has been obtained by the alkylation of an aromatic hydrocarbon with an olefinic hydrocarbon in the presence of a hydrogen fluoride catalyst; (2) a lower alkyl alcohol which possesses from about 3 to about 6 carbon atoms; and (3) a nonionic cosurfactant comprising an ethoxylated n-alcohol which possesses from about 12 to about 15 carbon atoms.

Hydroxylating aromatic hydrocarbons

Abstract: A process for the hydroxylation of aromatic hydrocarbons by hydrogen peroxide, consisting in reacting said compounds in the presence of synthetic zeolites which contain heteroatoms, both replaced and exchanged. The reaction is carried out at a temperature comprised between 80° C. and 120° C. and in the presence of the hydrocarbon only or in the presence of a solvent which permits, at least partially, to admix the aromatic hydrocarbon with the hydrogen peroxide.

Process for the manufacture of aromatic polycarboxylic acids having delta Y values below ten

Abstract: A process for purifying aromatic polycarboxylic acid produced by liquid phase catalytic oxidation of polyalkyl aromatic hydrocarbon to remove undesirable aldehyde aromatic carboxylic acid and other impurities including the step of contacting an aqueous solution of said impure acid and hydrogen with a noble metal-containing catalyst, our improvement comprising eliminating any gas phase during the contacting step and conducting said contacting step with said aqueous solution by maintaining hydrogen at about 10 to about 75 percent of saturation in the liquid reaction medium to produce purified aromatic polycarboxylic acid having delta Y values below ten.

Process for the isolation of beta -sitosterol

Abstract: A process is provided herein for the isolation and recovery of beta -sitosterol substantially free of alpha -sitosterol from the unsaponifiables obtained from crude soap skimmings or from a crude sterol mixture containing beta -sitosterol, alpha -sitosterol and campesterol The starting material is treated with a solvent mixture containing an aromatic hydrocarbon, a polar organic solvent having the ability to form hydrogen bonds, and water The aromatic hydrocarbon can be replaced by a mixture of an aromatic and an aliphatic hydrocarbon When the starting material is dissolved the reaction product is precipitated, preferably by cooling the solution, whereafter it is separated from the mother liquor The obtained product is essentially free of alpha -sitosterol

Conversion of heavy petroleum oils

Abstract: Heavy petroleum oils, such as vacuum resids and heavy fractions of tar sands and shale oil, are partially converted to more volatile hydrocarbons by mixing with light aromatic hydrocarbons and treatment of the mixture with a transalkylation catalyst, for example a Friedel-Crafts catalyst such as aluminum chloride. It is believed that the conversion is essentially a transalkylation, i.e. the resid undergoes dealkylation with concurrent alkylation of the light aromatic hydrocarbon.

Triblock polymers of a monovinyl aromatic compound and myrcene

Abstract: A tacky thermoplastic elastomeric linear triblock polymer corresponding to the formula A-B-A is made from a monovinyl aromatic hydrocarbon and myrcene. A is a polymer block of a monovinyl aromatic hydrocarbon, e.g. styrene, having an average molecular weight between 2,000 and 100,000 and a glass transition temperature above 25° C. B is a polymeric block of myrcene (7-methyl-3-methylene-1,6-octadiene, C10 H16) having an average molecular weight between 10,000 and 1,000,000 and a glass transition temperature below -40° C. B constitutes from 40 to 80 percent of the total. The products are made by sequential polymerization with an organolithium initiator.

Selective alkylation of aromatic hydrocarbons using a mixed ethylene/propylene alkylation agent

Abstract: Aromatic hydrocarbons are selectively alkylated using an alkylating mixture containing both ethylene and propylene. By employing a zeolite ZSM-12 based alkylation catalyst, essentially only the propylene from the olefin-containing alkylation mixture will react with the aromatic hydrocarbon to thereby form both an alkylaromatic product enriched in propylated alkylaromatic and a propylene-free residual olefin-containing mixture enriched in the unreacted ethylene.

Anti-corrosion coating for metals

Abstract: An anti-corrosion coating for metals comprising a mixture of aluminum paste or zinc paste, microcrystalline wax, aromatic hydrocarbon resin, chlorinated rubber, neutral barium sulfonate, chlorinated solvent, aromatic hydrocarbon solvent, and mineral spirits.

Process for the preparation of a cycloalkene through partial hydrogenation of the corresponding aromatic hydrocarbon

Abstract: The invention relates to a process for the preparation of a cycloalkene through partial hydrogenation of the corresponding aromatic hydrocarbon in the gas phase in the presence of a ruthenium catalyst. This hydrogenation process is carried out in the presence of water vapor.

Process for the production of oxygenated hydrocarbons from synthesis gas

Abstract: Oxygenated hydrocarbons are produced by reacting in a liquid medium carbon monoxide and hydrogen in the presence of a particulate catalyst comprising a supported rhodium component at an elevated temperature, typically in the range 150 to 300°C and an elevated pressure, typically greater than 50 bars. Suitable liquid media include water, an alcohol, a Carboxylic acid, an ester, a ketone, an ether or an aromatic hydrocarbon. The rhodium catalyst may be supported on silica and is desirably combined with other metals.

Benzylic functionalization of arene(tricarbonyl)chromium complexes

Abstract: The complexation of a Cr(CO)3 unit to an aromatic hydrocarbon enhances the benzylic position towerds attack by base and the resulting carbanion reacts with carbonyl compounds to produce a complexed alcohol; this reaction may be used to functionalize the benzylic position of an aromatic hydrocarbon.

Process for producing block copolymer resin

Abstract: In producing a block copolymer resin having vinyl aromatic hydrocarbon polymer blocks such as of styrene and polymer blocks primarily composed of conjugated diene such as of butadiene successively through living polymers using an organolithium compound as a catalyst in an aliphatic solvent, the vinyl aromatic hydrocarbon monomer for forming the vinyl aromatic hydrocarbon polymer block is added at a controlled rate, at the stage when the vinyl aromatic hydrocarbon content in the polymer formed has reached a certain value, higher than the polymerization rate of the vinyl aromatic hydrocarbon monomer at the polymerization temperature but at a rate which can maintain the solubility parameter of the liquid phase portion in the polymerization system at 7.7 or less, whereby a block copolymer resin with good transparency and impact strength can be produced with good productivity.

Distribution of aromatic hydrocarbons in port valdez, alaska

Abstract: The distribution of aromatic hydrocarbons in Port Valdez, Alaska, was studied. Such compounds are present in the effluent from the ballast treatment plant located at the terminal of the Trans Alaska Pipeline. The plant processes 10 to 20 million gallons per day (mgd) of ballast water from arriving tankers. The principal organic components found in the treated effluent are benzene, toluene, and xylenes/ethylbenzene. Such volatile aromatic hydrocarbons comprise up to 50 percent of the total organic load in the effluent, and are discharged at a rate of 60 to 80 gallons per day. State regulations limit aromatic hydrocarbon content in waters outside the mixing zone to 10 micrograms per liter concentration. Distribution of the aromatic hydrocarbons in the receiving waters was studied by collecting and analyzing samples at the boundary of the mixing zone and throughout the fjord. Vertical and horizontal transects were designed for sample collection, and a sensitive analytical procedure capable of detect...

Process for desulfurizing and refining hydrocarbon fraction containing large quantities of aromatic components

Abstract: Desulfurization and refining of aromatic hydrocarbon fraction containing organic sulfur compounds by catalytic hydrotreating can be performed with a high desulfurization rate (99 wt. % or higher) and without a significant loss (1 mol % or less) of the aromatic components. The improved process is characterized by preliminary sulfurization treatment of the catalyst of Co--Mo system, Ni--Mo system or Ni--Co--Mo system using thiophenes, and hydrotreating of the aromatic hydrocarbon fraction using thus treated catalyst at a relatively high temperature.

Copolymer tackifying resins containing dicyclopentadine, vinyl aromatic hydrocarbon and a substituted benzene (halogen, lower alkyl, or hydroxyl) and adhesives containing these resins

Abstract: Solid copolymer tackifying resins based on dicyclopentadiene, a vinylaromatic hydrocarbon and a benzene carrying 1 to 3 lower alkyl, hydroxyl or halogen substituents and adhesive formulations containing these resins.

Partial hydrogenating method of aromatic hydrocarbon

Abstract: PURPOSE: To improve the selectivity of a cycloolefin useful as a raw material for polyamides, etc. in partially hydrogenating an aromatic hydrocarbon with hydrogen in the presence of water, a ruthenium hydrogenating catalyst and an additive, by using cobalt sulfate as the additive. CONSTITUTION: An aromatic hydrocarbon, e.g. benzene, toluene, xylene or a lower alkylbenzene, is partially hydrogenated with hydrogen in the presence of water, a ruthenium hydrogenating catalyst containing ruthenium essentially and cobalt sulfate, preferably at 50W200°C 1W200kg/cm 2 to give a cycloolefin by a simple operation in high yilled. The amounts of the water, hydrogenating catalyst and cobalt sulfate are preferably as follows: water in an amount of 0.1W5 times that of the hydrocarbon, 0.1W10wt% hydrogenating catalyst, and 0.001W30 times cobalt sulfate basing on the amount of the hydrogenating catalyst. The hydrogenating catalyst is preferably supported on a carrier, and a co- catalyst, e.g. copper or silver, may be contained therein. COPYRIGHT: (C)1982,JPO&Japio

Headspace gas chromatographic determination of aromatic hydrocarbons in natural and waste water

Abstract: The possibilities of using headspace analysis of aromatic hydrocarbon traces in aqueous solutions with changing values of the partition coefficients are discussed. A variant of headspace analysis of the simplest aromatic hydrocarbon in natural and waste water is described. It involves two-step gaseous extraction of a sample in vessels of varying volume before and after the equilibrium phase is replaced with a pure gas (air or nitrogen). This method permits to analyse 5–50 ml water samples with benzene and toluene contents varying from the ppb to the ppm range within an error not exceeding 155. The analysis time is about 1.5 h. The presence of non-volatile organic or mineral substances does not influence the determination. This method is unsuitable to heterogeneous systems (aqueous oil emulsions): before carrying out the analysis for the hydrocarbon content these systems have to be homogenized first.

Halogen-containing resin composition containing ester plasticizer

Abstract: A plasticizer for halogen-containing resins which is composed of at least one compound expressed by the general formula ##STR1## wherein R1 represents an aromatic hydrocarbon group containing 1 or 2 aromatic rings or an alicyclic hydrocarbon group having 4 to 37 carbon atoms, R2 1, R2 2, R2 3 and R2 4 are identical or different and each represents an aliphatic hydrocarbon group having 2 to 17 carbon atoms, R3 1, R3 2, R3 3 and R3 4 are identical or different and each represents an aliphatic hydrocarbon group having 2 to 22 carbon atoms, an aromatic hydrocarbon group or a heterocyclic group, each of n1, n2, n3 and n4 is 0 or an integer of 1 to 20 and the sum of these is 1 to 20, and each of m1, m2, m3 and m4 is 0 or 1 and the sum of these is 1 to 4. The plastizer has superior thermal stability, processability and compatibility. Halogen-containing resins plasticized with this plasticizer have especially high utility in applications requiring thermal stability.

Production of hydrocarbon resin

Abstract: PURPOSE:To prevent the formation of gel and to improve the color tone and tackifying property of a hydrocarbon resin, by using a homogeneous catalyst composed of aluminum halide, etc. in the production of the hydrocarbon resin by the cationic polymerization of a monomer mixture containing conjugated chain diolefin. CONSTITUTION:The objective hydrocarbon resin can be produced by the cationic polymerization of a monomer mixture containing a 4-5C conjugated chain diolefin (e.g. 1,3-pentadiene), using a homogeneous catalyst obtained by compounding (A) an aluminum halide (preferably aluminum chloride), (B) an unsaturated polymer having low molecular weight (preferably a hydrocarbon resin or an oily polymer produced in the production of the hydrocarbon resin), (C) an aromatic hydrocarbon (e.g. benzene) and (D) an oxygen-containing organic compound (e.g. alcohol). The amounts of the components B and C are 0.5-10 pts.(wt.) and 1-10pts. per 1pt. of the component A, and that of the component D is 0.2-0.8mol per 1mol of the component A. USE:Useful as a tackifying agent of a pressure-sensitive adhesive type by mixing with natural rubber or synthetic rubber.