Method of producing aromatic hydrocarbons including: supplying a raw material stream to a C6 separation column, supplying an upper discharge stream from the C6 separation column to a first gasoline hydrogenation unit, and supplying a lower discharge stream from the C6 separation column to a C7 separation column; supplying an upper discharge stream from the C7 separation column to a hydrodealkylation reaction unit and supplying a lower discharge stream from the C7 separation column to a C8 separation column; separating benzene from discharged streams from the first gasoline hydrogenation unit and the hydrodealkylation reaction unit; removing a lower discharge stream from the C8 separation column and supplying an upper discharge stream from the C8 separation column to a second extractive distillation column; and separating styrene from a lower discharge stream of the second extractive distillation column and separating xylene from an upper discharge stream of the second extractive distillation column.

Method of producing aromatic hydrocarbons including: supplying a raw material stream to a C6 separation column, supplying an upper discharge stream from the C6 separation column to a first gasoline hydrogenation unit, and supplying a lower discharge stream from the C6 separation column to a C7 separation column; supplying an upper discharge stream from the C7 separation column to a hydrodealkylation reaction unit and supplying a lower discharge stream from the C7 separation column to a C8 separation column; separating benzene from discharged streams from the first gasoline hydrogenation unit and the hydrodealkylation reaction unit; removing a lower discharge stream from the C8 separation column and supplying an upper discharge stream from the C8 separation column to a second extractive distillation column; and separating styrene from a lower discharge stream of the second extractive distillation column and separating xylene from an upper discharge stream of the second extractive distillation column.

An apparatus for producing aromatic hydrocarbons including: a C6 separation column; a C7 separation column; a first gasoline hydrogenation unit; a C8 separation column; an extractive distillation column; a hydrodealkylation reaction unit; and a second gasoline hydrogenation unit.

An apparatus for producing aromatic hydrocarbons including: a C6 separation column; a C7 separation column; a first gasoline hydrogenation unit; a C8 separation column; an extractive distillation column; a hydrodealkylation reaction unit; and a second gasoline hydrogenation unit.

A method of producing aromatic hydrocarbons including: supplying a raw material stream to a C6 separation column, supplying an upper discharge stream from the C6 separation column to a first gasoline hydrogenation unit, and supplying a lower discharge stream from the C6 separation column to a C7 separation column; supplying an upper discharge stream from the C7 separation column to the first gasoline hydrogenation unit and supplying a lower discharge stream from the C7 separation column to a C8 separation column; separating benzene and toluene from a discharge stream from the first gasoline hydrogenation unit; removing a lower discharge stream from the C8 separation column and supplying an upper discharge stream from the C8 separation column to a second extractive distillation column; and separating styrene from a lower discharge stream from the second extractive distillation column and separating xylene from an upper discharge stream from the second extractive distillation column.

A method of producing aromatic hydrocarbons including: supplying a raw material stream to a C6 separation column, supplying an upper discharge stream from the C6 separation column to a first gasoline hydrogenation unit, and supplying a lower discharge stream from the C6 separation column to a C7 separation column; supplying an upper discharge stream from the C7 separation column to the first gasoline hydrogenation unit and supplying a lower discharge stream from the C7 separation column to a C8 separation column; separating benzene and toluene from a discharge stream from the first gasoline hydrogenation unit; removing a lower discharge stream from the C8 separation column and supplying an upper discharge stream from the C8 separation column to a second extractive distillation column; and separating styrene from a lower discharge stream from the second extractive distillation column and separating xylene from an upper discharge stream from the second extractive distillation column.

The present invention is directed to improved methods and systems for increasing the efficiency of a dehydrogenation section of an alkenyl aromatic hydrocarbon production facility, wherein an alkyl aromatic hydrocarbon, such as ethylbenzene, is dehydrogenated to produce an alkenyl aromatic hydrocarbon, such as styrene. The disclosed methods are more energy-efficient and cost effective than currently known methods for manufacturing styrene. The methods and systems advantageously utilize multiple reheat exchangers arranged in a series and/or parallel configuration that result in an energy consumption reduction and, consequently, a utility cost savings, as well as a reduction in styrene manufacturing plant investment costs.

The present invention is directed to improved methods and systems for increasing the efficiency of a dehydrogenation section of an alkenyl aromatic hydrocarbon production facility, wherein an alkyl aromatic hydrocarbon, such as ethylbenzene, is dehydrogenated to produce an alkenyl aromatic hydrocarbon, such as styrene. The disclosed methods are more energy-efficient and cost effective than currently known methods for manufacturing styrene. The methods and systems advantageously utilize multiple reheat exchangers arranged in a series and/or parallel configuration that result in an energy consumption reduction and, consequently, a utility cost savings, as well as a reduction in styrene manufacturing plant investment costs.

The present invention relates to additive composition for controlling and inhibition of polymerization of aromatic vinyl monomers including styrene comprising (a) one or more of nitroxide (i.e. nitroxyl) compounds, and characterized in that the said composition further comprises one or more of (b) aliphatic amines selected from a group comprising tertiary amines, secondary amines and primary amines. In one embodiment, the present invention also relates to method of use of presently provided composition. In another embodiment, the present invention also relates to method of controlling and inhibiting polymerization of aromatic vinyl monomers including styrene by employing presently provided composition. In still another embodiment, the present invention also relates to method of preparation of presently provided composition.

The present invention relates to additive composition for controlling and inhibition of polymerization of aromatic vinyl monomers including styrene comprising (a) one or more of nitroxide (i.e. nitroxyl) compounds, and characterized in that the said composition further comprises one or more of (b) aliphatic amines selected from a group comprising tertiary amines, secondary amines and primary amines. In one embodiment, the present invention also relates to method of use of presently provided composition. In another embodiment, the present invention also relates to method of controlling and inhibiting polymerization of aromatic vinyl monomers including styrene by employing presently provided composition. In still another embodiment, the present invention also relates to method of preparation of presently provided composition.