Aromatic hydrocarbon

About: Aromatic hydrocarbon is a research topic. Over the lifetime, 5814 publications have been published within this topic receiving 55499 citations. The topic is also known as: arene & arenes.

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.

Pyrimidine compound and medicinal composition thereof

Abstract: A novel pyrimidine compound having an excellent antagonistic activity against adenosine receptors (A1, A2A, and A2B receptors). Specifically, it is a compound represented by the following formula, a salt of the compound, or a solvate of either. (I) In the formula, R1 and R2 are the same or different and each represents hydrogen, optionally substituted C1-6 alkyl, etc.; R3 represents hydrogen, halogeno, etc.; R4 represents an optionally substituted C6-14 aromatic hydrocarbon ring group, optionally substituted 5- to 14-membered nonaromatic heterocyclic group having at least one unsaturated bond, etc.; and R5 represents an optionally substituted C6-14 aromatic hydrocarbon ring group or optionally substituted 5- to 14-membered aromatic heterocyclic group.

Production of benzene-insoluble organic aluminumoxy compound

Abstract: PURPOSE: To produce the subject compound having excellent catalyst activity by bringing a solution of an aluminoxane into contact with an active hydrogen- containing compound. CONSTITUTION: For example, an organoaluminum compound, such as trialkylaluminum, is added and reacted with a suspension of magnesium chloride hydrate, etc., in a hydrocarbon medium and preferably recovered as an aromatic hydrocarbon solution. The resultant aluminoxane solution is then brought into contact with a hydrocarbon solvent (e.g., benzene or toluene) containing an active hydrogen-containing compound (preferably alcohols, such as a methanol), preferably at -50 to +200°C for 1-150hr to afford the objective compound containing an A component soluble in the benzene at 160°C in an amount of ≤10% expressed in terms of Al atoms. Furthermore, the active hydrogen- containing compound is used in an amount of 0.1-5mol (preferably 0.2-3mol) based on Al atoms in the aluminoxane solution. COPYRIGHT: (C)1990,JPO&Japio

Extraction of Aromatic Hydrocarbons from Aromatic/Aliphatic Mixtures Using Chloroaluminate Room-Temperature Ionic Liquids as Extractants

Abstract: The extraction of aromatic hydrocarbons from aromatic/aliphatic mixtures was investigated using chloroaluminate ionic liquids as extractants. Three types of chloroaluminate ionic liquids, i.e., 1-butyl-3-methylimidazolium chloride−aluminum chloride (BMIC/AlCl3), trimethylamine hydrochloride− aluminum chloride (Me3NHCl/AlCl3), and triethylamine hydrochloride−aluminum chloride (Et3NHCl/AlCl3), were prepared and used to extract aromatic hydrocarbons. Chloroaluminate ionic liquids have strong aromatic hydrocarbon solvent capacities, small solvent capacities for n-heptane, and good extractive performances. BMIC−2.0AlCl3 exhibits better extractive performance than Me3NHCl−2.0AlCl3 and Et3NHCl−2.0AlCl3. Both the benzene distribution coefficient and aromatic/n-heptane selectivity increase with an increasing ratio of AlCl3/organic salt (Et3NHCl) in ionic liquids. The steric effect of substituent groups on the benzene ring lowers the aromatic extractive performance. The π complextion between aromatic molecules with...

Alkylation of Benzene or Toluene with MeOH or C2H4 over ZSM-5 or .beta. Zeolite: Effect of the Zeolite Pore Openings and of the Hydrocarbons Involved on the Mechanism of Alkylation

Abstract: A comparative study of the alkylation of benzene or toluene with MeOH or C{sub 2}H{sub 4} over a medium (ZSM-5) and a large pore ({beta}) zeolite of comparable acidities was carried out. It was observed that the reaction temperature in combination with the structure of the zeolite plays an important role in the reactions that take place. The maximum yield of either the primary or secondary alkylation products may occur at an intermediate temperature, which is lower over {beta} zeolite. Due to its pore structure, {beta} zeolite favors secondary alkylation reactions and also disproportionation reactions of the generated alkylaromatics to a higher extent than ZSM-5 does. MeOH generates both primary and secondary alkylation products, while C{sub 2}H{sub 4} favors oligomerization reactions, primary alkylation reactions, and particularly, disproportionation reactions. Toluene is more reactive than benzene. The aromatic/alkylating agent molar ratio plays an important role in the relative importance of the reactions that take place. The size of the pores of the zeolite in combination with the sizes of the aromatic hydrocarbons and the alkylating agents employed determines whether the alkylation occurs via a Langmuir-Henshelwood (LH) or Rideal-Eley (RE) mechanism. When a LH mechanism occurs, the alkylation rate passes through a maximummore » with respect to the concentration of the aromatic hydrocarbon employed; no such maximum occurs for the RE mechanism.« less