Abstract: A process for converting ethylbenzene, by which ethylbenzene in a feedstock containing C8 aromatic hydrocarbon is converted to benzene at a high degree of conversion is disclosed. The process for converting ethylbenzene includes bringing a C8 aromatic hydrocarbon mixed feedstocks containing ethylbenzene into contact with an acid type catalyst containing at least one metal selected from the group consisting of the metals belonging to Group VII and Group VIII in the presence of H2 to convert ethylbenzene to benzene. The feedstock contains C9-C10 aromatic hydrocarbons including ethyltoluene, and the ethyltoluene is converted to toluene together with the conversion of ethylbenzene.

Abstract: The invention provides techniques for reducing or altering the magnetic noise of an AC rotary electric machine. A magnetic noise reducing harmonic current of order n, whose frequency is n times the frequency of the fundamental frequency component of a polyphase AC current fed to an armature of a polyphase AC rotary electric machine, is superimposed on the polyphase AC current, thereby reducing or altering a harmonic component having a frequency (n?1) times the frequency of the fundamental frequency component and occurring due to a radial magnetic excitation force acting radially on an iron core of the AC rotary electric machine.

Abstract: A method for converting aromatic hydrocarbons by contacting an aromatic hydrocarbon starting material including benzene and having a non-aromatic compound content of 1% by weight or less, with a catalystto generate useful C7 and C8 aromatic hydrocarbons while reducing the catalyst deactivation.

Abstract: The invention provides techniques for reducing or altering the magnetic noise of an AC rotary electric machine. A magnetic noise reducing harmonic current of order n, whose frequency is n times the frequency of the fundamental frequency component of a polyphase AC current fed to an armature of a polyphase AC rotary electric machine, is superimposed on the polyphase AC current, thereby reducing or altering a harmonic component having a frequency (n?1) times the frequency of the fundamental frequency component and occurring due to a radial magnetic excitation force acting radially on an iron core of the AC rotary electric machine.

Abstract: A catalyst composition with a high halogenated aromatics isomerization activity, a halogenated aromatic isomerization method using said catalyst composition, and a halogenated aromatics isomerization method capable of prolonging the life or regeneration period of the catalyst. The invention also includes a catalyst composition characterized in that the maximum diameter of secondary particles of the zeolite in the formed catalyst is 5 microns or less is used to improve the halogenated aromatics isomerization activity. Furthermore, if dissolved oxygen is decreased, the life or regeneration period of the catalyst can be prolonged.

Abstract: The present invention provides a catalyst composition with a high halogenated aromatics isomerization activity, a halogenated aromatic isomerization method using said catalyst composition, and a halogenated aromatics isomerization method capable of prolonging the life or regeneration period of the catalyst.

Abstract: A method for efficiently resolving optical isomers, in which a discriminating liquid consisting of a discriminating agent capable of discriminating optical isomers and a diluent are brought into contact with a mixture containing said optical isomers in countercurrent flow, to resolve the optical isomers by adsorption separation, distillation separation, absorption separation or membrane separation, and recovered at an optical isomer content of 5 wt % or less for recycled use, under one or more of the following conditions: (a) the dielectric constant of the diluent is 30 or less and the viscosity of the discriminating liquid is 0.

Abstract: An adsorbing and separating agent for halogenated aromatic compounds and an adsorbing and separating method for the compounds, using an adsorbent which has a porosity of from 0.20 cc/cc to 0.37 cc/cc, a packing density of from 0.50 g/ml to 0.70 g/ml, and a grain size of from 0.1 mm to 1.0 mm.

Abstract: The invention provides an adsorbing and separating agent for halogenated aromatic compounds, and an adsorbing and separating method for the compounds. Using the adsorbing and separating agent of the invention gives a high-purity, halogenated aromatic compound isomer. In the adsorbing and separating method of the invention, the adsorbent used is prevented from being deteriorated and its life can be prolonged. The adsorbent for separating halogenated aromatic compounds of the invention has a porosity o from 0.20 cc/cc to 0.37 cc/cc, a packing density of from 0.50 g/ml to 0.70 g/ml, and a grain size of from 0.1 mm to 1.0 mm. With the adsorbent, a halogenated aromatic compound isomer is separated and recovered; or a halogenated aromatic compound having a dissolved oxygen content of at most 15 ppm by weight is separated and recovered with an adsorbent. In the method, at least one, high-purity isomer can be efficiently separated and recovered from a mixture of halogenated aromatic compound isomers.

Abstract: Aromatic hydrocarbons are efficiently converted by bringing feedstock containing from 5 to 50% by weight of an aromatic hydrocarbon having an ethyl group and a C.sub.9 alkyl aromatic hydrocarbon into contact with a catalyst capable of disproportionation, trans-alkylation and dealkylation, a secondary particle diameter of a zeolite in the catalyst being 10 .mu.m or less.

Abstract: An improved process for producing xylene from feedstock containing C.sub.9 alkyl aromatic hydrocarbons with the aid of a catalyst capable of disproportionation, rearrangement, and dealkylation, wherein said improvement comprises performing the reaction in the presence of an aromatic hydrocarbon having one or more ethyl groups in an amount of 5 to 50 wt %.