The present disclosure provides a modified catalyst, and preparation method and a method for producing aromatic hydrocarbons by aromatization of olefins using the modified catalyst. The modified catalyst comprises an acidic molecular sieve and an olefin aromatization active metal component, the total acid amount of the catalyst as measured by NH.sub.3-TPD method is not higher than 0.35 mmol/g, and ratio of the strong acid to weak acid is within a range of 0.8-1.2.

Provided is an oxidizing composition, in which a liquid medium is substantially inert in the presence of an oxidizing electrophile contained in the liquid medium. The composition comprises (a) an oxidizing electrophile comprising a main group element in oxidized form and at least one conjugate anion of an oxygen acid; (b) a non-oxidizable liquid selected from a fluorinated hydrocarbon, a sulfone, a deactivated arene, a deactivated aliphatic, a deactivated heteroarene, a deactivated heteroaliphatic, and a combination thereof; and (c) optionally one or more salt additives. Further provided are a method of using the oxidizing composition to oxidize a substrate and a method of generating and/or regenerating an oxidizing electrophile comprising a main group element.

Provided is an oxidizing composition, in which a liquid medium is substantially inert in the presence of an oxidizing electrophile contained in the liquid medium. The composition comprises (a) an oxidizing electrophile comprising a main group element in oxidized form and at least one conjugate anion of an oxygen acid; (b) a non-oxidizable liquid selected from a fluorinated hydrocarbon, a sulfone, a deactivated arene, a deactivated aliphatic, a deactivated heteroarene, a deactivated heteroaliphatic, and a combination thereof; and (c) optionally one or more salt additives. Further provided are a method of using the oxidizing composition to oxidize a substrate and a method of generating and/or regenerating an oxidizing electrophile comprising a main group element.

A method for preparing a purified styrene composition includes providing a crude hydrocarbon composition containing styrene, subjecting the crude hydrocarbon composition to a distillation in a divided-wall column to produce an overhead hydrocarbon stream, a bottom hydrocarbon stream and a side hydrocarbon stream and subjecting the side hydrocarbon stream to at least one crystallization step to obtain a purified styrene composition.

A method for preparing a purified styrene composition includes providing a crude hydrocarbon composition containing styrene, subjecting the crude hydrocarbon composition to a distillation in a divided-wall column to produce an overhead hydrocarbon stream, a bottom hydrocarbon stream and a side hydrocarbon stream and subjecting the side hydrocarbon stream to at least one crystallization step to obtain a purified styrene composition.

Processes and systems for dehydrogenating ethylbenzene may include mixing a steam stream and an ethylbenzene stream to form a feed mixture. The ethylbenzene/steam feed mixture may then be fed to a dehydrogenation reactor containing an alkali metal promoted catalyst. A liquid, selected from an alkali metal liquid, an alkali metal compound liquid, or a liquid solution comprising an alkali metal, may be injected into a feed stream, such as the steam stream, the ethylbenzene stream, or the ethylbenzene/steam feed mixture. Following injection, the liquid vaporizes and disperses into the feed stream upstream of the dehydrogenation reactor. The liquid may be maintained as a liquid from a point upstream of injection to an injection nozzle. The liquid is dispersed through the injection nozzle, in liquid form, to form droplets of liquid dispersed in the feed stream, which evaporate and/or dissolve into the vaporous feed stream.

Processes and systems for dehydrogenating ethylbenzene may include mixing a steam stream and an ethylbenzene stream to form a feed mixture. The ethylbenzene/steam feed mixture may then be fed to a dehydrogenation reactor containing an alkali metal promoted catalyst. A liquid, selected from an alkali metal liquid, an alkali metal compound liquid, or a liquid solution comprising an alkali metal, may be injected into a feed stream, such as the steam stream, the ethylbenzene stream, or the ethylbenzene/steam feed mixture. Following injection, the liquid vaporizes and disperses into the feed stream upstream of the dehydrogenation reactor. The liquid may be maintained as a liquid from a point upstream of injection to an injection nozzle. The liquid is dispersed through the injection nozzle, in liquid form, to form droplets of liquid dispersed in the feed stream, which evaporate and/or dissolve into the vaporous feed stream.

A method for preparing a purified styrene composition with a styrene yield of at least 80%. The method comprises providing a crude composition containing styrene, and subjecting the crude composition to at least one crystallization step. The at least one crystallization step comprises at least one static crystallization stage and at least one dynamic crystallization stage.

A method for preparing a purified styrene composition with a styrene yield of at least 80%. The method comprises providing a crude composition containing styrene, and subjecting the crude composition to at least one crystallization step. The at least one crystallization step comprises at least one static crystallization stage and at least one dynamic crystallization stage.

A catalyst support comprising at least 95% silicon carbide, having surface areas of ≤10 m.sup.2/g and pore volumes of ≤1 cc/g. A method of producing a catalyst support, the method including mixing SiC particles of 0.1-20 microns, SiO.sub.2 and carbonaceous materials to form an extrusion, under inert atmospheres, heating the extrusion at temperatures of greater than 1400° C., and removing residual carbon from the heated support under temperatures below 1000° C. A catalyst on a carrier, comprising a carrier support having at least about 95% SiC, with a silver solution impregnated thereon comprising silver oxide, ethylenediamine, oxalic acid, monoethanolamine and cesium hydroxide. A process for oxidation reactions (e.g., for the production of ethylene oxide, or oxidation reactions using propane or methane), or for endothermic reactions (e.g., dehydrogenation of paraffins, of ethyl benzene, or cracking and hydrocracking hydrocarbons).