Abstract: A process is provided which is capable of producing olefins stably and efficiently by a metathesis reaction of identical or different olefins while preventing the lowering in metathesis catalyst activity due to trace impurities such as heteroatom-containing compounds that are contained in a starting olefin. The olefin production process includes supplying a starting olefin containing more than 0 ppm by weight to not more than 10 ppm by weight of one or more kinds of heteroatom-containing compounds to a reactor that contains a metathesis catalyst and an isomerization catalyst, the metathesis catalyst including at least one metal element selected from the group consisting of tungsten, molybdenum and rhenium, the isomerization catalyst including calcined hydrotalcite or yttrium oxide, and performing a metathesis reaction of identical or different olefins.

Abstract: A method for manufacturing an olefin through reaction between the same type of or different types of raw material olefins to obtain an olefin having a structure different from the structure of the raw material olefins, the method including using a catalyst containing at least one type of metal element selected from the group consisting of tungsten, molybdenum, and rhenium together with other specific catalysts. In the method, side reactions of a metathesis reaction can be suppressed and the selectivity of a desired product can be increased by facilitating double bond isomerization of raw material olefins. Furthermore, the desired product can be obtained efficiently at a high productivity by maintaining the activity of a metathesis catalyst for a long term and suppressing deterioration of performance of a catalyst (isomerization catalyst) for facilitating double bond isomerization of the raw material olefins.

Abstract: In a process for producing olefins by a metathesis reaction comprising feeding an olefin gas to pass the olefin through a catalyst bed in the presence of hydrogen gas to convert the olefin into another kind of olefin, the catalyst bed having a catalyst including at least one metal selected from the group consisting of tungsten, molybdenum, rhenium, niobium, tantalum and vanadium, and a co-catalyst including a basic compound having at least one metal selected from the group consisting of Group Ia (alkali metals), Group IIa (alkaline earth metals), Group IIb and Group IIIa of the periodic table, the improvement lies in controlling the superficial velocity of the gas passing through the catalyst bed to 0.01 to 2.0 m/sec. According to the present invention, the presence of hydrogen gas dramatically increases the durability of the metathesis catalytic activity and the by-production of paraffins is suppressed.

Abstract: A process is provided which is capable of producing olefins stably and efficiently by a metathesis reaction of identical or different olefins while preventing the lowering in metathesis catalyst activity due to trace impurities such as heteroatom-containing compounds that are contained in a starting olefin. The olefin production process includes supplying a starting olefin containing more than 0 ppm by weight to not more than 10 ppm by weight of one or more kinds of heteroatom-containing compounds to a reactor that contains a metathesis catalyst and an isomerization catalyst, the metathesis catalyst including at least one metal element selected from the group consisting of tungsten, molybdenum and rhenium, the isomerization catalyst including calcined hydrotalcite or yttrium oxide, and performing a metathesis reaction of identical or different olefins.

Abstract: In a process for producing olefins by a metathesis reaction comprising feeding an olefin gas to pass the olefin through a catalyst bed in the presence of hydrogen gas to convert the olefin into another kind of olefin, the catalyst bed having a catalyst including at least one metal selected from the group consisting of tungsten, molybdenum, rhenium, niobium, tantalum and vanadium, and a co-catalyst including a basic compound having at least one metal selected from the group consisting of Group Ia (alkali metals), Group IIa (alkaline earth metals), Group IIb and Group IIIa of the periodic table, the improvement lies in controlling the superficial velocity of the gas passing through the catalyst bed to 0.01 to 2.0 m/sec. According to the present invention, the presence of hydrogen gas dramatically increases the durability of the metathesis catalytic activity and the by-production of paraffins is suppressed.

Abstract: An electronic apparatus comprising a radio transmitter is disclosed. In a computer system (1) having a radio transmission circuit (3) of a phase modulation type supplied with power from a power supply (4) of a switching type, the switching frequency of the power supply (4) is determined based on the comparison frequency for the sampling operation of a PLL circuit (10) of the radio transmitter, thereby removing the power noises generated from the switching regulator of the radio transmitter of a phase modulation type.

Abstract: An electronic apparatus comprising a radio transmitter is disclosed. In a computer system (1) having a radio transmission circuit (3) of a phase modulation type supplied with power from a power supply (4) of a switching type, the switching frequency of the power supply (4) is determined based on the comparison frequency for the sampling operation of a PLL circuit (10) of the radio transmitter, thereby removing the power noises generated from the switching regulator of the radio transmitter of a phase modulation type.

Abstract: A process is provided for the preparation of an indole from aniline or a derivative thereof and a polyhydric alcohol. The reaction is carried out in the presence of a catalyst composed of a carrier having a specific surface area of at least 10 m.sup.2 /g and silver supported on the carrier. The catalyst also contains as an additional component a specific amount of at least one element selected from Co, Fe and Ni. Deterioration in catalytic performance of the catalyst during the reaction and its regeneration are therefore minimized.

Abstract: Disclosed herein is to react an aniline and an ethylene glycol at a superatmospheric pressure in preparing an indole by subjecting the aniline and ethylene glycol to a gas-phase catalytic reaction in the presence of a catalyst, thereby improving the selectivity of the reaction and the service life of the catalyst.

Abstract: Disclosed herein is a preparation process for an indole, which process comprises subjecting an N-(.beta.-hydroxy)-alkylaniline, in the presence of a catalyst and at a super-atmospheric pressure, to a gas-phase catalytic reaction. The present process improves the selectivity of the reaction and the service life of the catalyst.

Abstract: In a process for preparing an indole by reacting an aniline with a diol, a catalyst the activity of which has been reduced through its use in the reaction is brought into contact with an inert gas containing 5 vol. % or less of oxygen so that the catalyst is regenerated for its repeated utilization. The activity of the regenerated catalyst is enhanced further when it is subjected to a reducing treatment for activation upon its reutilization.

Abstract: This invention relates to a process for the selective ortho-alkylation of a phenolic compound having at least one ortho-positioned hydrogen atom by catalytically reacting the phenolic compound with an alcohol in the vapor phase. In this process, the reaction of the phenolic compound with the alcohol is carried out at a temperature of from 300.degree. to 550.degree. C. in the presence of a catalyst containing manganese oxide, silicon oxide and one or more additives selected from group (A) consisting of germanium oxide, tin oxide and lead oxide, or a catalyst containing manganese oxide, silicon oxide, one or more additives selected from the aforesaid group (A), and one or more additives selected from group (B) consisting of alkali metal oxides and alkaline earth metal oxides.

Abstract: This invention relates to a process for the selective ortho-alkylation of a phenolic compound having at least one ortho-positioned hydrogen atom by catalytically reacting the phenolic compound with an alcohol in the vapor phase. In this process, the reaction of the phenolic compound with the alcohol is carried out at a temperature of from 300.degree. to 550.degree. C. in the presence of a catalyst containing manganese oxide and one or more additives selected from group (A) consisting of germanium oxide, tin oxide and lead oxide, or a catalyst containing manganese oxide, one or more additives selected from the aforesaid group (A), and one or more additives selected from group (B) consisting of alkali metal oxides and alkaline earth metal oxides. The catalyst used in this invention exhibits not only excellent catalytic activity in the selective ortho-alkylation of phenols, continuous stability of the activity, good shapeability and good mechanical strength but also effective utilization of alcohols.

Abstract: A process for producing selectively o-alkylated phenols wherein an anisole having at least one ortho positioned hydrogen atom is contacted with a mixed oxide catalyst in the vapor phase.

Abstract: A process for the production of alkyl phenols having at least one o-alkyl radical comprising catalytically reacting a phenolic compound having at least one o-positioned hydrogen atom with an alcohol in the vapor phase in the presence of a manganese oxide containing catalyst modified with a compound of at least one of the alkali metals.

Abstract: This invention relates to a process for the selective ortho-alkylation of a phenolic compound having at least one ortho-positioned a hydrogen atom by catalytically reacting the phenolic compound with an alcohol in the vapor phase. In this process, the reaction of the phenolic compound with the alcohol is carried out at a temperature of from 300.degree. to 550.degree. C. in the presence of a mixed oxide catalyst of manganese, silicon, and one or more additives selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide, and barium oxide. The catalyst used in this invention exhibits not only excellent catalytic activity in the selective ortho-alkylation of phenols but also continuous stability of the activity, good shapability, and good mechanical strength.

Abstract: The selective alkylation of a phenolic compound having a hydrogen atom in at least one of the ortho positions is achieved by reacting the phenolic compound with an alcohol in the vapor phase in the presence of a catalyst containing mixed oxides of chromium and tin. The catalyst can additionally contain iron oxide, sulfate radical, or a combination thereof.