Many linear alpha olefin (LAO) syntheses form a range of LAO products when oligomerizing ethylene in the presence of a Ziegler-type catalyst. The range of products typically requires a plurality of distillation columns to separate the LAO products up to a desired carbon count, but such approaches may be energy- and capital-intensive. LAO product separation using at least one dividing wall column may lessen these burdens. Methods for separating LAOs may comprise: providing a pre-processed product stream comprising Cg+ linear alpha olefins (LAOs) to a first of a series of distillation columns, at least one member of the series of distillation columns comprising a dividing wall column; and separating an overhead stream comprising a first LAO from the dividing wall column and one or more side streams from the dividing wall column, each side stream comprising a different LAO that also differs from the first LAO.

Many linear alpha olefin (LAO) syntheses form a range of LAO products when oligomerizing ethylene in the presence of a Ziegler-type catalyst. The range of products typically requires a plurality of distillation columns to separate the LAO products up to a desired carbon count, but such approaches may be energy- and capital-intensive. LAO product separation using at least one dividing wall column may lessen these burdens. Methods for separating LAOs may comprise: providing a pre-processed product stream comprising Cg+ linear alpha olefins (LAOs) to a first of a series of distillation columns, at least one member of the series of distillation columns comprising a dividing wall column; and separating an overhead stream comprising a first LAO from the dividing wall column and one or more side streams from the dividing wall column, each side stream comprising a different LAO that also differs from the first LAO.

Many linear alpha olefin (LAO) syntheses form a range of LAO products when oligomerizing ethylene in the presence of a Ziegler-type catalyst. The range of products typically requires a plurality of distillation columns to separate the LAO products up to a desired carbon count, but such approaches may be energy- and capital-intensive. LAO product separation using at least one dividing wall column may lessen these burdens. Methods for separating LAOs may comprise: providing a pre-processed product stream comprising Cg+ linear alpha olefins (LAOs) to a first of a series of distillation columns, at least one member of the series of distillation columns comprising a dividing wall column; and separating an overhead stream comprising a first LAO from the dividing wall column and one or more side streams from the dividing wall column, each side stream comprising a different LAO that also differs from the first LAO.

The present invention pertains to a method for recovering a selective homogeneous hydrogenation catalyst and a method for reusing the recovered selective homogeneous hydrogenation catalyst. The method for recovering a selective homogeneous hydrogenation catalyst comprises: a step for synthesizing cyclododecene by selectively hydrogenating a first reaction solution containing cyclododecatriene, triphenylphosphine, formaldehyde, and ruthenium chloride, wherein a selective homogeneous hydrogenation catalyst is prepared during the selective hydrogenation reaction from the triphenylphosphine, formaldehyde, and ruthenium chloride to synthesize the cyclododecene; and a step for distilling and separating unreacted cyclododecatriene and cyclododecadiene, as well as the product cyclododecene, from a second reaction solution in which the cyclododecene synthesis has been completed, and recovering the selective homogeneous hydrogenation catalyst.

The present invention pertains to a method for recovering a selective homogeneous hydrogenation catalyst and a method for reusing the recovered selective homogeneous hydrogenation catalyst. The method for recovering a selective homogeneous hydrogenation catalyst comprises: a step for synthesizing cyclododecene by selectively hydrogenating a first reaction solution containing cyclododecatriene, triphenylphosphine, formaldehyde, and ruthenium chloride, wherein a selective homogeneous hydrogenation catalyst is prepared during the selective hydrogenation reaction from the triphenylphosphine, formaldehyde, and ruthenium chloride to synthesize the cyclododecene; and a step for distilling and separating unreacted cyclododecatriene and cyclododecadiene, as well as the product cyclododecene, from a second reaction solution in which the cyclododecene synthesis has been completed, and recovering the selective homogeneous hydrogenation catalyst.

The present invention pertains to a method for recovering a selective homogeneous hydrogenation catalyst and a method for reusing the recovered selective homogeneous hydrogenation catalyst. The method for recovering a selective homogeneous hydrogenation catalyst comprises: a step for synthesizing cyclododecene by selectively hydrogenating a first reaction solution containing cyclododecatriene, triphenylphosphine, formaldehyde, and ruthenium chloride, wherein a selective homogeneous hydrogenation catalyst is prepared during the selective hydrogenation reaction from the triphenylphosphine, formaldehyde, and ruthenium chloride to synthesize the cyclododecene; and a step for distilling and separating unreacted cyclododecatriene and cyclododecadiene, as well as the product cyclododecene, from a second reaction solution in which the cyclododecene synthesis has been completed, and recovering the selective homogeneous hydrogenation catalyst.

Systems and methods for separating a mixture comprising C.sub.4 hydrocarbons and a solvent have been disclosed. The mixture is produced as a bottom stream of a rectifier column. The mixture is processed in at least two heating and flash-evaporating cycles to remove at least some C.sub.4 hydrocarbons as vapor streams. The resulted liquid stream is further degassed in a degasser column to produce a recycle vapor stream and a lean solvent stream.

Systems and methods for separating a mixture comprising C.sub.4 hydrocarbons and a solvent have been disclosed. The mixture is produced as a bottom stream of a rectifier column. The mixture is processed in at least two heating and flash-evaporating cycles to remove at least some C.sub.4 hydrocarbons as vapor streams. The resulted liquid stream is further degassed in a degasser column to produce a recycle vapor stream and a lean solvent stream.

Systems and methods for separating a mixture comprising C.sub.4 hydrocarbons and a solvent have been disclosed. The mixture is produced as a bottom stream of a rectifier column. The mixture is processed in at least two heating and flash-evaporating cycles to remove at least some C.sub.4 hydrocarbons as vapor streams. The resulted liquid stream is further degassed in a degasser column to produce a recycle vapor stream and a lean solvent stream.

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.