A multi-stage dehydrogenation process including contacting, in a first stage, a feed stream comprising a hydrocarbon and steam with a dehydrogenation catalyst under dehydrogenation conditions to yield a first stage effluent, heating the first stage effluent, and contacting, in a second stage, the heated first stage effluent with a dehydrogenation catalyst under dehydrogenation conditions to yield a second stage effluent comprising a dehydrogenation product, wherein the first stage includes a first reactor and a second reactor arranged in parallel, and wherein the second stage includes a third reactor connected in series with the first reactor and the second reactor. A multi-stage dehydrogenation system for carrying out dehydrogenation is also provided.

A multi-stage dehydrogenation process including contacting, in a first stage, a feed stream comprising a hydrocarbon and steam with a dehydrogenation catalyst under dehydrogenation conditions to yield a first stage effluent, heating the first stage effluent, and contacting, in a second stage, the heated first stage effluent with a dehydrogenation catalyst under dehydrogenation conditions to yield a second stage effluent comprising a dehydrogenation product, wherein the first stage includes a first reactor and a second reactor arranged in parallel, and wherein the second stage includes a third reactor connected in series with the first reactor and the second reactor. A multi-stage dehydrogenation system for carrying out dehydrogenation is also provided.

A long-life catalyst which can be easily and inexpensively manufactured and has high activity and suppressed leakage of metal. A catalyst according to some embodiments includes: a substrate; and a first metal atom as a catalytic center. The substrate contains a non-metallic atom and a second metal atom, and the non-metallic atom is any one selected from the group consisting of a group 15 element, a group 16 element and a group 17 element.

A long-life catalyst which can be easily and inexpensively manufactured and has high activity and suppressed leakage of metal. A catalyst according to some embodiments includes: a substrate; and a first metal atom as a catalytic center. The substrate contains a non-metallic atom and a second metal atom, and the non-metallic atom is any one selected from the group consisting of a group 15 element, a group 16 element and a group 17 element.

A method for preparing alpha-methylstyrene according to one embodiment of the present disclosure includes dehydrating a dimethylbenzyl alcohol solution in a reactor under an acid catalyst to prepare alpha-methylstyrene, where a reaction product after the dehydration reaction comprises a first reaction product including a first alpha-methylstyrene; and a second reaction product including vapor (H.sub.2O), a second alpha-methylstyrene and unreacted materials; and separating the second alpha-methylstyrene and the unreacted materials comprised in the second reaction product and recirculating the second alpha-methylstyrene and the unreacted materials to the reactor, a temperature inside the reactor during the dehydration reaction is 135 C. or higher, and a content of the acid catalyst is from 100 ppm to 1,500 ppm based on a total weight of dimethylbenzyl alcohol of the dimethylbenzyl alcohol solution.

A method for preparing alpha-methylstyrene according to one embodiment of the present disclosure includes dehydrating a dimethylbenzyl alcohol solution in a reactor under an acid catalyst to prepare alpha-methylstyrene, where a reaction product after the dehydration reaction comprises a first reaction product including a first alpha-methylstyrene; and a second reaction product including vapor (H.sub.2O), a second alpha-methylstyrene and unreacted materials; and separating the second alpha-methylstyrene and the unreacted materials comprised in the second reaction product and recirculating the second alpha-methylstyrene and the unreacted materials to the reactor, a temperature inside the reactor during the dehydration reaction is 135 C. or higher, and a content of the acid catalyst is from 100 ppm to 1,500 ppm based on a total weight of dimethylbenzyl alcohol of the dimethylbenzyl alcohol solution.

A method for reducing the mutagenicity of polycyclic aromatic compounds (PAC's) having one or more bay regions which involves alkylating the PAC's with an alkylating agent in the presence of a catalyst to lower the mutagenicity down to as much as about 0.1. The resulting alkylated polycyclic aromatic compounds retain their physical and chemical properties for safe industrial use including as rubber processing oils, inks, etc.

A method for reducing the mutagenicity of polycyclic aromatic compounds (PAC's) having one or more bay regions which involves alkylating the PAC's with an alkylating agent in the presence of a catalyst to lower the mutagenicity down to as much as about 0.1. The resulting alkylated polycyclic aromatic compounds retain their physical and chemical properties for safe industrial use including as rubber processing oils, inks, etc.

Provided is a process for oxidizing an alkene. The process comprises contacting an alkene, and either an oxidizing electrophile comprising a main group element in oxidized form or an oxidant and a reduced form of the oxidizing electrophile, in a liquid medium comprising an oxygen acid and optionally one or more additives selected from a non-oxidizable liquid, a salt additive, a Lewis acid, and water, to provide an oxygenate and a reduced form of the oxidizing electrophile. The process optionally further comprises separating the oxygenate and the reduced form of the oxidizing electrophile. The oxygenate can be further hydrolyzed to form an alcohol, diol, or polyol.

Provided is a process for oxidizing an alkene. The process comprises contacting an alkene, and either an oxidizing electrophile comprising a main group element in oxidized form or an oxidant and a reduced form of the oxidizing electrophile, in a liquid medium comprising an oxygen acid and optionally one or more additives selected from a non-oxidizable liquid, a salt additive, a Lewis acid, and water, to provide an oxygenate and a reduced form of the oxidizing electrophile. The process optionally further comprises separating the oxygenate and the reduced form of the oxidizing electrophile. The oxygenate can be further hydrolyzed to form an alcohol, diol, or polyol.