A preparation method for optically active citronellal, which can obviously enhance the catalytic stability of an optically active transition metal catalyst for asymmetric hydrogenation of homogeneous catalysis and thereby achieve higher turnover numbers. In the preparation method for optically active citronellal, a substrate is subjected to an asymmetric hydrogenation reaction in the presence of the transition metal catalyst to generate the optically active citronellal, wherein the transition metal catalyst is obtained by reacting a transition metal compound with an optically active ligand containing two phosphorus atoms, and the raw material of the substrate is one of neral and geranial or a combination thereof to control the hydroxyl value to be less than or equal to 6 mgKOH/g and/or the iron content to be less than or equal to 50 ppm in the raw material of the substrate for the asymmetric hydrogenation reaction.

A preparation method for optically active citronellal, which can obviously enhance the catalytic stability of an optically active transition metal catalyst for asymmetric hydrogenation of homogeneous catalysis and thereby achieve higher turnover numbers. In the preparation method for optically active citronellal, a substrate is subjected to an asymmetric hydrogenation reaction in the presence of the transition metal catalyst to generate the optically active citronellal, wherein the transition metal catalyst is obtained by reacting a transition metal compound with an optically active ligand containing two phosphorus atoms, and the raw material of the substrate is one of neral and geranial or a combination thereof to control the hydroxyl value to be less than or equal to 6 mgKOH/g and/or the iron content to be less than or equal to 50 ppm in the raw material of the substrate for the asymmetric hydrogenation reaction.

A preparation method for optically active citronellal, which can obviously enhance the catalytic stability of an optically active transition metal catalyst for asymmetric hydrogenation of homogeneous catalysis and thereby achieve higher turnover numbers. In the preparation method for optically active citronellal, a substrate is subjected to an asymmetric hydrogenation reaction in the presence of the transition metal catalyst to generate the optically active citronellal, wherein the transition metal catalyst is obtained by reacting a transition metal compound with an optically active ligand containing two phosphorus atoms, and the raw material of the substrate is one of neral and geranial or a combination thereof to control the hydroxyl value to be less than or equal to 6 mgKOH/g and/or the iron content to be less than or equal to 50 ppm in the raw material of the substrate for the asymmetric hydrogenation reaction.

The present invention relates to processes for preparing isoprene and mono-olefins comprising at least six carbon atoms. In one aspect, a process comprises (a) hydroformylating a mixed C4 olefin stream, wherein the mixed C4 olefin stream comprises 1-butene, 2-butene, and optionally isobutene, with a hydroformylation catalyst, wherein the hydroformylation catalyst comprises rhodium with monodentate organophosphorous ligand and optionally polydentate organophosphorous ligand, to produce a mixture comprising linear and branched C5 aldehydes; (b) separating the branched C5 aldehydes from the linear C5 aldehydes to provide a branched C5 aldehyde stream and a linear C5 aldehyde stream; (c) dehydrating the branched C5 aldehydes in the branched C5 aldehyde stream using a dehydration catalyst to form a stream comprising isoprene; (d) hydrogenating the linear C5 aldehydes in the linear C5 aldehyde stream to form a C5 alcohol stream; (e) dehydrating the C5 alcohols in the C5 alcohol stream with a second dehydration catalyst to form a C5 olefin stream; (f) hydroformylating the C5 olefins in the C5 olefin stream to generate a C6 aldehyde stream; (g) hydrogenating the C6 aldehydes in the C6 aldehyde stream to form a C6 alcohol stream; and (h) dehydrating the C6 alcohols in the C6 alcohol stream with a third dehydration catalyst to form a C6 olefin stream.

The present invention relates to processes for preparing isoprene and mono-olefins comprising at least six carbon atoms. In one aspect, a process comprises (a) hydroformylating a mixed C4 olefin stream, wherein the mixed C4 olefin stream comprises 1-butene, 2-butene, and optionally isobutene, with a hydroformylation catalyst, wherein the hydroformylation catalyst comprises rhodium with monodentate organophosphorous ligand and optionally polydentate organophosphorous ligand, to produce a mixture comprising linear and branched C5 aldehydes; (b) separating the branched C5 aldehydes from the linear C5 aldehydes to provide a branched C5 aldehyde stream and a linear C5 aldehyde stream; (c) dehydrating the branched C5 aldehydes in the branched C5 aldehyde stream using a dehydration catalyst to form a stream comprising isoprene; (d) hydrogenating the linear C5 aldehydes in the linear C5 aldehyde stream to form a C5 alcohol stream; (e) dehydrating the C5 alcohols in the C5 alcohol stream with a second dehydration catalyst to form a C5 olefin stream; (f) hydroformylating the C5 olefins in the C5 olefin stream to generate a C6 aldehyde stream; (g) hydrogenating the C6 aldehydes in the C6 aldehyde stream to form a C6 alcohol stream; and (h) dehydrating the C6 alcohols in the C6 alcohol stream with a third dehydration catalyst to form a C6 olefin stream.

A method for preparing an aldehyde including forming a reaction product including an aldehyde by reacting an olefin-based compound with a synthetic gas in a hydroformylation reactor in the presence of a hydroformylation catalyst; introducing the reaction product including the aldehyde to a vaporizer; separating low-boiling point components of the reaction product from an upper part of a vaporizer catch pot included in the vaporizer; separating high-boiling point components of the reaction product from a lower part of the vaporizer catch pot; and recirculating at least a portion of the low-boiling point components separated from an upper part of the vaporizer catch pot back to the vaporizer.

A method for preparing an aldehyde including forming a reaction product including an aldehyde by reacting an olefin-based compound with a synthetic gas in a hydroformylation reactor in the presence of a hydroformylation catalyst; introducing the reaction product including the aldehyde to a vaporizer; separating low-boiling point components of the reaction product from an upper part of a vaporizer catch pot included in the vaporizer; separating high-boiling point components of the reaction product from a lower part of the vaporizer catch pot; and recirculating at least a portion of the low-boiling point components separated from an upper part of the vaporizer catch pot back to the vaporizer.

A method for preparing an aldehyde including forming a reaction product including an aldehyde by reacting an olefin-based compound with a synthetic gas in a hydroformylation reactor in the presence of a hydroformylation catalyst; introducing the reaction product including the aldehyde to a vaporizer; separating low-boiling point components of the reaction product from an upper part of a vaporizer catch pot included in the vaporizer; separating high-boiling point components of the reaction product from a lower part of the vaporizer catch pot; and recirculating at least a portion of the low-boiling point components separated from an upper part of the vaporizer catch pot back to the vaporizer.

A catalyst molded body, a production method thereof and a method for preparing cyclic ketone using the same, including: (a) producing a mixed powder including a catalyst powder and a binder; (b) producing a slurry by mixing an aqueous alkali hydroxide solution with the mixed powder; and obtaining a catalyst molded body by molding and heat-treating the slurry.

A catalyst molded body, a production method thereof and a method for preparing cyclic ketone using the same, including: (a) producing a mixed powder including a catalyst powder and a binder; (b) producing a slurry by mixing an aqueous alkali hydroxide solution with the mixed powder; and obtaining a catalyst molded body by molding and heat-treating the slurry.