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.

Embodiments of the present invention relate to processes to prepare a spent catalyst fluid from a hydroformylation process for precious metal recovery. In one embodiment, a process comprises (a) removing a spent catalyst fluid from an active hydroformylation reaction system, wherein the spent catalyst fluid comprises the hydroformylation reaction catalyst and is substantially free of non-hydrolyzable triorganophosphorous compounds; and (b) adding a non-hydrolyzable triorganophosphorous compound to the spent catalyst fluid from step (a) prior to storing the fluid or prior to shipping for precious metal recovery.

Disclosed herein are methods to rejuvenate a deactivated hydroformylation catalyst solution wherein the solution comprises rhodium, polyphosphoramidite ligands, and polyphosphoramidite ligand degradation products. In some embodiments, such methods comprise adding a peroxide to the deactivated hydroformylation catalyst solution.

Provided is a method of preparing an acrylonitrile dimer including: supplying an acrylonitrile monomer, a phosphorus-based catalyst, and an alcohol solvent to a reactor to perform a dimerization reaction to produce dimerized reactants (S10); cooling the dimerized reactants to crystallize the phosphorus-based catalyst (S20); separating the crystallized phosphorus-based catalyst (S30); and supplying the dimerized reactants from which the phosphorus-based catalyst is separated to a distillation column to separate the acrylonitrile dimer (S40).

Disclosed herein are methods of treating a hydroformylation catalyst solution wherein the solution comprises rhodium, polyphosphoramidite ligands, and polyphosphoramidite ligand degradation products and wherein the hydroformylation catalyst solution is used to hydroformylate an olefin in an operating hydroformylation unit. In some embodiments, such methods comprise contacting the catalyst solution with a peroxide in the operating hydroformylation unit.

Disclosed herein are methods to rejuvenate a deactivated hydroformylation catalyst solution wherein the solution comprises rhodium, polyphosphoramidite ligands, and polyphosphoramidite ligand degradation products. In some embodiments, such methods comprise adding a peroxide to the deactivated hydroformylation catalyst solution.

The invention relates to a process for separating one or more components from a mixture by a membrane separation in whichdepending on the component to be separatedan acid or a base is added to the mixture before the membrane separation.

Disclosed herein are methods to rejuvenate a deactivated hydroformylation catalyst solution wherein the solution comprises rhodium, polydentate phosphine ligands, and polydentate phosphine ligand degradation products. In one embodiment, such methods comprise adding a peroxide to the deactivated hydroformylation catalyst solution.

Disclosed herein are methods to rejuvenate a deactivated hydroformylation catalyst solution wherein the solution comprises rhodium, polydentate phosphine ligands, and polydentate phosphine ligand degradation products. In one embodiment, such methods comprise adding a peroxide to the deactivated hydroformylation catalyst solution.