Showing papers on "Aromatic hydrocarbon published in 1994"

Deep catalytic oxidation of aromatic hydrocarbon mixtures : reciprocal inhibition effects and kinetics

Abstract: Deep catalytic oxidation of gas emissions containing volatile organic compounds (VOC) is a widely employed technology for air pollution control. The deep catalytic oxidation kinetics of different aromatic hydrocarbons, in lean mixtures, over a Pt catalyst has been investigated. The reactivity increases in the order benzene > toluene > ethylbenzene > o-xylene > styrene. An apparent zeroth-order kinetics with respect to hydrocarbon concentration has been observed; the dependence on the oxygen partial pressure is more complex. Experiments with mixtures containing up to four hydrocarbons have been carried out. Remarkable effects on reaction rate and selectivity have been evidenced; the strongest inhibiting effect is shown by styrene and increases in a reverse order with respect to that of reactivity. A significant increase in the ignition temperature may occur in real burners. A kinetic model assuming strong irreversible adsorption of the aromatics and nonequilibrium adsorption of the oxygen over different sites has been proposed.

Metabolic diversity of aromatic hydrocarbon-degrading bacteria from a petroleum-contaminated aquifer

Abstract: We characterized bacteria from contaminated aquifers for their ability to utilize aromatic hydrocarbons under hypoxic (oxygen-limiting) conditions (initial dissolved oxygen concentration about 2 mg/l) with nitrate as an alternate electron acceptor. This is relevant to current intense efforts to establish favorable conditions for in situ bioremediation. Using samples of granular activated carbon slurries from an operating groundwater treatment system, we isolated bacteria that are able to use benzene, toluene, ethylbenzene, or p-xylene as their sole source of carbon under aerobic or hypoxic-denitrifying conditions. Direct isolation on solid medium incubated aerobically or hypoxically with the substrate supplied as vapor yielded 10(3) to 10(5) bacteria ml-1 of slurry supernatant, with numbers varying little with respect to isolation substrate or conditions. More than sixty bacterial isolates that varied in colony morphology were purified and characterized according to substrate utilization profiles and growth condition (i.e., aerobic vs. hypoxic) specificity. Strains with distinct characteristics were obtained using benzene compared with those isolated on toluene or ethylbenzene. In general, isolates obtained from direct selection on benzene minimal medium grew well under aerobic conditions but poorly under hypoxic conditions, whereas many ethylbenzene isolates grew well under both incubation conditions. We conclude that the conditions of isolation, rather than the substrate used, will influence the apparent characteristic substrate utilization range of the isolates obtained. Also, using an enrichment culture technique, we isolated a strain of Pseudomonas fluorescens, designated CFS215, which exhibited nitrate dependent degradation of aromatic hydrocarbons under hypoxic conditions.

Silanes with hydrophilic groups, their synthesis and use as surfactants in aqueous media

Abstract: Silanes of the general formula (see Formula I) are prepared, wherein R1, R2 and R3 in the molecule are the same or different and represent aliphatic or aromatic hydrocarbon groups, R4 is a divalent hydrocarbon group with 4 to 12 carbon atoms and a lateral hydroxyl group, wherein the hydrocarbon group can be interrupted by an ether oxygen, R5 is a hydrophilic, ionic group. A method for synthesizing these compounds is described. The silanes greatly lower the surface tension of aqueous solutions, the surface tension being reduced to values of about 23 mN/m. The silanes are biologically degradable and have pronounced surfactant properties.

The physiology of aromatic hydrocarbon degrading bacteria

Abstract: Aromatic hydrocarbons are ubiquitous in nature. Indeed, next to glucosyl residues, the benzene ring is the most widely distributed unit of chemical structure in nature (Dagley 1981). The amount and variety of aromatic hydrocarbons generated by commercial and industrial activities has continued to increase over the years. The occurrence of such compounds is a cause for great concern due to their potential hazard to the well being of both plants and animals. Benzene, toluene, ethylbenzene, styrene and the xylenes are among the 50 largest-volume industrial chemicals produced, with production figures of the order of millions of tonnnes per year. These compounds are widely used as fuels and industrial solvents. In addition, they and the polynuclear aromatic compounds provide the starting materials for the production of pharmaceuticals, agrochemicals, polymers, explosives and many other everyday products (Smith 1990). The use of man-made aromatic hydrocarbons has inevitably led to their release (either accidental or otherwise) into the environment and this problem is still escalating in spite of governmental intervention.

Activators for inorganic peroxy compounds

Abstract: The invention concerns the use of N-acylated pyroglutamic acid derivatives of the formula (I ou II), in which R1 is preferably H or Na and R2 is an optionally substituted aliphatic or aromatic hydrocarbon group, preferably a straight-chain alkyl group, as activators for inorganic peroxy compounds in aqueous systems, in particular for low-temperature bleaches. The invention also concerns bleaching, washing, cleaning and disinfecting agents containing such activators. The bleaching power of the compounds identified as activators is at least equivalent to that of tetraacetylethylenediamine (TAED) and exceeds it in some cases.

Formation of Aromatic Hydrocarbons in Decane and Kerosene Flames at Reduced Pressure

Abstract: The formation of frequently discussed soot precursors has been compared in decane and kerosene flames A specific study on the influence of equivalence ratio on the formation of some species (acetylene, benzene, vinyl benzene and phenyl acetylene) showed that in decane flames aromatic hydrocarbons are formed from acetylene whereas in kerosene flames the main source is the aromatic part of the fuel From this result it seems to be reasonable to represent kerosene as a mixture of decane (90%) and toluene (10%) when developing a detailed kinetic mechanism to predict benzene formation in flames burning kerosene The mechanism was checked by comparison of computed mole fraction profiles with measured profiles of a sooting kerosene-oxygen-argon flame with an equivalence ratio of 22 and of a decane flame with the same equivalence ratio

Use of titanium and zirconium compounds as homogeneous catalyst and novel titanium and zirconium compounds

Abstract: PURPOSE: To improve reaction efficiency by using a homogenous catalyst consisting of specific compds. containing Ti and Zr when an olefinic or an acetylenic unsaturated hydrocarbon is polymerized or oligomerized. CONSTITUTION: A compd. represented by formula I (wherein M is Ti or Zr; X 1 and X 2 are each a halogen or a 1-20C aliphatic or aromatic hydrocarbon; O-O is groups represented by formulae II, III; R 1 and R 2 are each a steric hinderance alkyl, OR' or silyl; R' is a 1-20C aliphatic or aromatic hydrocarbon; R 3 and R 4 are each H, a 1-20C aliphatic or aromatic hydrocarbon, silyl or OR'; Y is methylene, ethylene or a divalent crosslinking group such as S, O or the like; (n) is 0 or 1) [e.g.; 2,2'-S(4-Me, 6-tBuC 6 H 2 O) 2 Ti(CH 2 Ph) 2 ] is prepared. In the presence of a heterogenous catalyst comprising this compd., an olefinic or acetylenic unsaturated hydrocarbon (e.g.; ethene) is polymerized or oligomerized. COPYRIGHT: (C)1995,JPO

Method for producing a cycloolefin

Abstract: A method for producing a cycloolefin, which comprises partially hydrogenating a monocyclic aromatic hydrocarbon in the presence of water and a ruthenium catalyst supported on silica modified by zirconium oxide.

Spectroscopic Properties of Polycyclic Aromatic Compounds. Part IV: Effect of Solvent Polarity and Nitromethane on the Fluorescence Emission Behavior of Select Bipolycyclic Aromatic Hydrocarbons

Abstract: Fluorescence emission behavior is reported for 1,1'-binaphthalene, 2,2'-binaphthalene, 9,9'-bianthracene, 9,9'-biphenanthrene, 1,1'-methylene-bisnaphthalene, and 1,1',2,2'-tetrahydro-5,5'-biacenaphthylene dissolved in organic nonelectrolyte solvents of varying polarity, refractive index, and dielectric constant. Fluorescence measurements are used to classify the six bipolycyclic aromatic hydrocarbon (bi-PAH) solutes as either solvatochromic probe or nonprobe molecules, depending upon whether measured fluorescence properties vary with solvent nature. Of the bi-PAHs studied, only 9,9'-bianthracene exhibited probe character. Possible correlations between 9,9'-bianthracene's maximum intensity emission wavelength and select functions of solvent refractive index and dielectric constant were examined. Also reported is the effect that nitromethane has on bi-PAH fluorescence emission intensities.

Oxadiazole compound and its production

Abstract: PURPOSE: To obtain an oxadiazole compound having stable film-forming property as an organic electroluminescent material, useful for luminescent material, electron transfer material, etc., and especially resistant to deterioration in long- term storage. CONSTITUTION: This oxadiazole compound is expressed by formula I [A 1 and A 2 are each a (substituted)aromatic hydrocarbon group or a (substituted)aromatic heterocyclic group; R 1 to R 3 each is independently a halogen, a (substituted)alkyl, an alkoxy, trifluoromethyl or a (substituted)aryl; (l), (m) and (n) are each 0, 1, 2, 3 or 4; R 1 to R 3 may be the same to each other when (l), (m) and (n) each is ≥2], e.g. a compound of formula II (A is phenyl). The compound of formula I can be produced by reacting a tetrazole compound of formula II with an acid chloride of formula III [A is a (substituted)aromatic hydrocarbon group or a (substituted)aromatic heterocyclic group]. The compound of formula II is a new intermediate raw material producible by the tetrazolation of a cyano compound of formula IV. COPYRIGHT: (C)1995,JPO

Method for stripping contaminants from wastewater

Abstract: A method has been discovered for stripping aromatic hydrocarbon contaminants from wastewater and retaining the aromatic hydrocarbons on activated carbon. The wastewater is contacted countercurrently with stripping gas. The stripping gas is passed over a bed of activated carbon to regenerate the stripping gas. The entire volume of stripping gas is recycled to the stripping vessel. There is no purge of stripping gas or aromatic hydrocarbons to the atmosphere. The removed aromatic hydrocarbons are retained by the activated carbon and periodically recovered. An activated carbon particularly adapted for retaining and recovering aromatic hydrocarbons has been found.

Method of manufacturing methylidene-group-containing alpha , omega -unsaturated oligomers from alpha , omega -diolefins in the presence of organoaluminum compounds as catalysts

Abstract: A method of manufacturing methylidene-group-containing (alpha),(omega)-unsaturated oligomers from (alpha),(omega)-diolefins in the presence of a catalytic amount of organoaluminum compounds, wherein the (alpha),(omega)-diolefins are reacted in the liquid phase, at 150 degrees-350 degrees C., and the organoaluminum compounds have formula AlX3 or AlX2H, where X represents an aliphatic, alicyclic, or aromatic hydrocarbon group with 1-30 C atoms. The higher molecular weight hydrocarbons manufactured according to this method are substantially linear oligomers which contain reactive double bonds.

Process for preparing low density ethylene copolymers

Abstract: Low density ethylene copolymers are obtainable by adding an aromatic hydrocarbon solution of a catalyst system, containing, as active components, metallocene complexes of metals of subgroups IV and V of the Periodic Table and oligomeric alumina compounds, to a mixture containing ethylene, comonomers and aliphatic hydrocarbons.

Hydrogenation of alkyl group-substituted conjugated diene-based polymer

Abstract: PURPOSE:To obtain a hydrogenated conjugated diene-based polymer excellent in weather and oxidation resistances by using a specific stable and readily handleable titanocene-based highly active hydrogenation catalyst capable of withstanding the storage for a long period and manifesting activities with good reproducibility in hydrogenation with a trace amount thereof. CONSTITUTION:This method for hydrogenating an alkyl group-substituted conjugated diene-based polymer is to use a catalyst comprising (A) a titanocene compound of the formula (R and R are each a 1-12C hydrocarbon, etc.; Cp is cyclopentadienyl ring), (B) a reducing agent, having reducing power and selected from an organomagnesium, an organozinc and an organoaluminum compounds, (C) a polymer having 0.3-1 fraction of olefinic unsaturated bonds in the side chain to the whole and 500-10000 number-average molecular weight and (D) an alcohol of the formula ROH (R is a 1-20C hydrocarbon) at 0.05-5 ratio of the components (A)/(B) and 0.05-10 ratio of the components (D)/(B), in bringing a conjugated diene-based polymer which is a monomer unit constituting a polymer chain in which 1-2 of two carbon atoms having an olefinic unsaturated bond are substituted with a 1-18C alkyl or a copolymer of the conjugated diene and a vinyl aromatic hydrocarbon into contact with hydrogen in an inert organic solvent and hydrogenating the olefinic unsaturated double bonds.

Asphalt composition containing highly coupled radial polymers

Abstract: A bituminous composition comprising a compatible bituminous component and a completely non-tapered radial block copolymer of a conjugated diolefin and a vinyl aromatic hydrocarbon wherein the polymer has from 3 to 6 arms, a molecular weight of from 150,000 to 400,000, a coupling efficiency of at least 95 percent, and a polyvinyl aromatic hydrocarbon blockiness of at least 98.5%.

Production of bismaleimide

Abstract: PURPOSE:To efficiently produce a bismaleimide useful for a laminating material, an electrical insulating material, an adhesive, etc., by subjecting an aromatic diamine and maleic anhydride to addition reaction in a specific mixed solvent, subjecting to ring closure reaction through dehydration in the presence of an acid catalyst and precipitating the reaction product. CONSTITUTION:An aromatic diamine of the formula [Y is CH2, C(CH3)2, C(CF3)2, etc.; R1 to R4 are H, halogen or 1-4C alkyl] and maleic anhydride are subjected to addition reaction in a mixed solvent of an aromatic hydrocarbon solvent and an aprotic polar solvent at >=50 deg.C to give a polymaleamic acid. Then, this compound is subjected to ring closure reaction through dehydration in the presence of an acid catalyst while azeotripically removing water prepared as a by-product together with an aromatic hydrocarbon solvent, the resultant reaction mixture is washed with water while maintaining a uniform solution state, the aromatic hydrocarbon solvent is distilled away until the amount of the aromatic hydrocarbon solvent removed reaches >=50wt.% and then >=1 pt.wt. of a solvent such as esters, ethers or ketones based on 1 pt.wt. of the remaining aromatic solvent is added to the reaction mixture. The resulting mixture is cooled to precipitate the objective bismaleimide.

Process for separating hydrocarbons using alkylene-bridged polysilsesquioxanes

Abstract: A process to separate at least two classes of hydrocarbons of a solution using an alkylene-bridged polysilsesquioxane adsorbent has been developed. The classes of hydrocarbons to be separated may be saturated hydrocarbons, unsaturated aliphatic hydrocarbons and aromatic hydrocarbons. The alkylene-bridging group may contain from about 2 to about 14 carbon atoms. A specific embodiment of the invention is one where the components of a solution of aromatic, unsaturated aliphatic, and saturated hydrocarbons are separated into an aromatic hydrocarbon portion, an unsaturated aliphatic hydrocarbon portion, and a saturated hydrocarbon portion where the adsorbent is an alkylene-bridged polysilsesquioxane.

Macrolides as antagonists of macrophilin binding immunosuppressants

Abstract: The invention provides macrolides of formula (I) wherein R1 is H, alkyl, aryl, or acyl; R2 is H, or -OR5, such that R5 is H, alkyl, aryl, or acyl; R3 is -CH2- or -CH2CH2-; and R4 is H, alkyl, acyl, or aryl; preferably wherein 'alkyl' refers to C1-6 alkyl; 'aryl' refers to an aromatic hydrocarbon radical having one or two aromatic rings; and 'acyl' is alkylcarbonyl or arylcarbonyl. Pharmaceutical compositions, pharmaceutical uses, assays, methods for producing the macrolides, and a novel producer strain are also provided.

Manufacture of ferrous picrate and additives containing same

Abstract: A process for preparing ferrous picrate is disclosed. The process includes the step of reacting under substantially non-oxidising conditions ferrous carbonate substantially free from ferric compounds with a substantially water-free solution of picric acid in a solvent medium to produce a solution of ferric picrate. The solvent medium is selected from aromatic hydrocarbon solvents, mixtures of aromatic hydrocarbon solvents, straight- or branched- chain aliphatic alcohols, mixtures of straight- or branched- chain aliphatic alcohols, and mixtures of straight- or branched- chain aliphatic alcohols and aromatic hydrocarbon solvents. The reaction is preferably carried out under a continuously maintained inert atmosphere and at a temperature between 10 °C and 120 °C.

Multi-inlay section thermal plastic elastic body and synthesis method

Abstract: The present invention relates to a kind of additive compound which is made from aromatic hydrocarbon with condensed nuclei (such as naphthalene or its homologous compound) and metal lithium in the mixed solvent of aromatic hydrocarbon and ether, or anionic block polymerization is conducted by using oligomerization diolefins synthesized with said additive compound, as initiator, using phenylethylene (S) and conjugated diolefins (D) as polymeric monomer, naphthenic hydrocarbon or aromatic hydrocarbon as solvent, ether or amine as micro-structure regulator of the product, and adopting three or more steps charging process, i.e. polymeric monomer charged in order S,D,S successively, the temp. for polymerization is 40-90 deg.C, the time of polymerization is 2-4hr, the concentration of polymeric liquid is 5-20%, the concentration of initiator is gauge synthesized in accordance with molecular weight of product.

Method for pretreating a catalyst slurry and a method for the continuous partial hydrogenation of a monocyclic aromatic hydrocarbon by using the pretreated catalyst slurry

Abstract: A method for pretreating a slurry containing a ruthenium catalyst for use in the continuous partial hydrogenation of monocyclic aromatic hydrocarbons is disclosed. In this method, the above-mentioned slurry is heat-treated at a temperature of from 60° to 180° C. for at least 10 minutes while agitating. By using the pretreated catalyst slurry in the above-mentioned continuous partial hydrogenation, partial hydrogenation reaction products can be efficiently obtained without suffering from the excess mixing of the components of the catalyst slurry into an oil phase containing the partial hydrogenation reaction products, thereby enabling operations and facilities required for separation to be simplified.

Vinyl-substituted benzylorganotin compound and a polymer thereof

Abstract: Disclosed are: a vinyl-substituted benzylorganotin compound represented by the following general formula A: ##STR1## wherein R 1 R 2 C═CR 3 --, R 4 , R 5 , R 6 and R 7 are each a group bonded to the benzene ring and R 1 to R 7 are each one of a hydrogen atom and a hydrocarbon group having 1 to 30 carbon atoms which is one of aliphatic, alicyclic and aromatic hydrocarbon groups, R 8 to R 10 are each a hydrocarbon group having 1 to 30 carbon atoms which is one of aliphatic, alicyclic and aromatic hydrocarbon groups and R 1 to R 10 may be the same or different from each other; a process for preparing a polymer comprising copolymerizing, in a hydrocarbon solvent in the presence of an organolithium compound as the initiator, (1) at least one of conjugated dienes and vinylaromatic hydrocarbons and (2) the organotin compound represented by the general formula A; a copolymer comprising (1) at least one of conjugated diene units and vinylaromatic hydrocarbon units and (2) units of a vinyl-substituted benzylorganotin compound monomer represented by the general formula A; and a rubber composition comprising 100 weight parts of a rubber material containing 30 weight parts or more of a polymer having number-average molecular weight of 5×10 4 to 80×10 4 which is obtained by the above process, 20 to 100 weight parts of carbon black and 0.1 to 5 weight parts of a vulcanizing agent.

Production of star type polymer

Abstract: PURPOSE: To inexpensively obtain the subject polymer useful as a resin additive, etc., for providing high fluidity and improving impact resistance by polymerizing an olefinic monomer in the presence of a silyl group-containing azo initiator and a silyl group-containing chain transfer agent and subjecting the resultant polymer to polycondensation by a sol-gel method. CONSTITUTION: An olefinic monomer (e.g. styrene) which may have a substituent group is subjected to radical polymerization reaction in the presence of a silyl group-containing azo initiator expressed by formula I [(x) is an integer of 0-2; R1 and R3 are each a monovalent saturated hydrocarbon; R2 is a 1-20C saturated hydrocarbon or an aromatic hydrocarbon] and a chain transfer agent consisting of a silyl group-containing thiol compound expressed by formula II [(y) is an integer of 0-2; R4 and R5 are each a monovalent hydrocarbon; R6 is a 1-6C divalent hydrocarbon or an aromatic hydrocarbon] [e.g. γ- mercaptopropyltrimethoxysilane) to afford a polymer having alkoxysilyl groups at the ends, which is then subjected to hydrolysis/polycondensation by a sol-gel method to provide the objective star type polymer. COPYRIGHT: (C)1996,JPO

Photochemistry of organic mixed crystals : carbazole/anthracene and benzimidazole/2,3-dimethylnaphthalene

Abstract: Among the mixed crystals between carbazole (1) or benzimidazole (2) and an aromatic hydrocarbon, such as naphthalene, phenanthrene and anthracene, only the carbazole/anthracene mixed crystal was found by powder X-ray diffraction spectroscopy and differential scanning calorimetry to constitute a molecular compound. Irradiation of this molecular compound gave 9-(9-carbazolyl)-9,10-dihydroanthracene (7) and 9-(9-carbazolyl)anthracene (8) both in the solid state and in an acetonitrile solution. The structure of 7 was established by X-ray crystallographic analysis. Benzimidazole showed no photoreactivity to aromatic hydrocarbons in the solid and solution states, except the irradiation with 2,3-dimethylnaphthalene in acetonitrile leading to the formation of 1-(1-benzimidazolyl)-2,3-dimethylnaphthalene (9).

Bisazo compounds as charge generating materials

Abstract: An electrophotographic photoconductor is disclosed, which comprises an electroconductive support and a photoconductive layer formed thereon comprising a bisazo pigment having the formula (I) serving as a charge generating material: ##STR1## wherein Ar represents a residual group of a coupler represented by ArH selected from the group consisting of: an aromatic hydrocarbon compound having a hydroxyl group, a heterocyclic compound having a hydroxyl group, an aromatic hydrocarbon compound having an amino group, a heterocyclic compound having an amino group, an aromatic hydrocarbon compound having a hydroxyl group and an amino group, a heterocyclic compound having a hydroxyl group and an amino group, an aliphatic compound having an enolic ketone group, and an aromatic hydrocarbon compound having an enolic ketone group. Further, charge generating materials and novel bisazo pigments for use in the electrophotographic photoconductor are disclosed.

Process for producing aromatic amide compounds useful as cyan coupler for color photographs

Abstract: There is disclosed a process for producing an aromatic amide compound of the general formula (4), including the steps of subjecting an o-nitrophenol compound of the general formula (1) to catalytic reduction in acetone or an aromatic hydrocarbon solvent under the presence of a nickel catalyst to give an o-aminophenol compound of the general formula (2); and (b) subjecting the o-aminophenol compound of the general formula (2) to condensation with an acid chloride compound having a sulfur content of 0.5% or less, based on the weight of the acid chloride compound, of the general formula (3) in acetone or an aromatic hydrocarbon solvent under an atmosphere of an inert gas having an oxygen concentration of 1% or less. The acid chloride compound having a sulfur content of 0.5% or less, based on the weight of the acid chloride compound, of the general formula (3) may be obtained by allowing a carboxylic acid compound of the general formula (5) to react with thionyl chloride and by concentrating the reaction mixture. Also disclosed is another process for producing an aromatic amide compound of the general formula (4), including the step of subjecting an o-aminophenol hydrochloride salt of the general formula (6) to condensation with an acid chloride compound having a sulfur content of 0.8% or less, based on the weight of the acid chloride compound, of the general formula (3) in an inert solvent.